[top]
000
FXUS62 KCHS 241451
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1051 AM EDT THU JUL 24 2008
.SYNOPSIS...
A WEAK COLD FRONT WILL STALL OUT WEST OF THE AREA TODAY AND
DISSIPATE TONIGHT. HIGH PRESSURE WILL EXTEND ACROSS THE REGION
THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A WEAKENING COLD FRONT APPEARS TO BE POSITIONED ACROSS THE UPSTATE
OF SOUTH CAROLINA AND NORTHERN GEORGIA THIS MORNING...WITH
NOTICEABLY LOWER DEWPOINT VALUES IN ITS WAKE. THE COLD FRONT IS EXPECTED
TO STALL AND DISSIPATE BEFORE REACHING THE FORECAST AREA TODAY.
MEANWHILE...A PRE-FRONTAL TROUGH...OR WHAT REMAINS OF THE LEE-SIDE
TROUGH...HAS MOVED INTO THE COASTAL PLAIN ALLOWING WINDS TO VEER
NORTHERLY.
WATER VAPOR IMAGERY DEPICTS VERY DRY AIR IN PLACE AT THE MID
LEVELS OVER THE AREA. FORECAST SOUNDINGS SHOW THAT THIS DRY AIR
WILL REMAIN IN PLACE THROUGH THE AFTERNOON...BUT ALSO SHOW A WEAK
CAP BELOW THE DRY AIR WITH A SHALLOW LAYER OF MOISTURE TRAPPED
BENEATH IT. THIS MOISTURE WILL BE SUFFICIENT TO PRODUCE A DECENT
CUMULUS FIELD THROUGH THE DAY.
IT APPEARS THAT IT WILL BE VERY DIFFICULT FOR ANY CONVECTION TO
DEVELOP THIS AFTERNOON GIVEN THE SHALLOW LOW LEVEL MOISTURE...VERY
DRY AIR IN THE MID LEVELS...AND WEAK CAPPING. HOWEVER...WITH HIGH
TEMPERATURES FORECAST TO BE IN THE LOWER-MID 90S AWAY FROM THE
COAST...DEWPOINTS IN THE UPPER 60S TO LOWER 70S AND GIVEN THE
CLIMATOLOGY FOR THIS TIME OF YEAR...IT IS HARD TO RULE OUT AN
ISOLATED SHOWER OR THUNDERSTORM DEVELOPING. WILL THEREFORE
MAINTAIN ISOLATED CONVECTION IN THE FORECAST FOR THE EASTERN 2/3
OF THE FORECAST AREA THIS AFTERNOON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
ANY LINGERING EVENING CONVECTION WILL QUICKLY DISSIPATE AFTER
SUNSET. WET GROUNDS FROM RECENT RAINFALLS...EXTENSIVE MID-LEVEL
DRY AIR AND LIGHT/CALM WINDS WILL SUPPORT THE DEVELOPMENT OF
PATCHY FOG AFTER MIDNIGHT. LOWS WILL RANGE FROM AROUND 70 WELL
INLAND TO THE UPPER 70S AT THE BEACHES.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY TROUGH WEDNESDAY WILL BE DOMINATED BY WEAK NORTHWESTERLY
FLOW ALOFT BETWEEN THE SOUTHERN PLAINS UPPER RIDGE AND AN UPPER
LEVEL TROUGH OVER THE GREAT LAKES/NORTHEASTERN STATES. AT THE
SURFACE...LEE SIDE TROUGHING MAINLY FROM CENTRAL NORTH CAROLINA TO
CENTRAL GEORGIA WILL BE COMMON.
BIGGEST CHALLENGE THIS FORECAST PERIOD IS THE POPS FOR FRIDAY AND
SATURDAY. ETA MOS AND GFS MOS ARE NOW IN AGREEMENT THAT POPS WILL BE
AT OR BELOW 10 PERCENT IN JUST ABOUT ALL AREAS BOTH DAYS. BASED ON
FORECAST SOUNDINGS...THIS SEEMS REASONABLE GIVEN DECENT CAP WITH 700
MB TEMPERATURES NEAR 8 CELSIUS AND DRY AIR ALOFT ESPECIALLY ON
FRIDAY. ADJUSTED POPS DOWN ON BOTH DAYS FROM THE PREVIOUS
FORECAST...BUT KEPT THEM ABOVE GUIDANCE ENOUGH TO MAINTAIN SLIGHT
CHANCE POPS BOTH AFTERNOONS. HAVE SOME CONCERN THAT THE MODELS
MAINTAIN THE DRIER AIR ALOFT TOO LONG AND THIS RESULTS IN LOWER POPS
THAN WOULD NORMALLY BE THE CASE. IN ADDITION...HAVE SOME CONCERN
THAT THERE WILL BE ENOUGH CONVERGENCE ALONG THE SEA BREEZE TO
OVERCOME THE CAP IN A FEW LOCATIONS BOTH DAYS.
DEEPER MOISTURE IS EXPECTED TO RETURN SATURDAY NIGHT AND REMAIN WITH
US THROUGH AT LEAST WEDNESDAY. THIS COMBINED WITH SURFACE DEWPOINTS
AT LEAST IN THE LOWER TO MID 70S AND UPPER LEVEL DISTURBANCES MOVING
ACROSS THE AREA SHOULD BE ENOUGH TO RESULT IN MAINLY SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AN EXPANDING CUMULUS AND/OR STRATO-CUMULUS FIELD HAS RESULTED IN
TEMPORARY MVFR CEILINGS AT BOTH KCHS AND KSAV AT TIMES THIS
MORNING...BUT EXPECT CEILINGS TO LIFT TO VFR LEVELS OR DISSIPATE
BY MIDDAY. VFR CONDITIONS WILL THEN PREVAIL...ALTHOUGH SOME PATCHY
GROUND FOG COULD DEVELOP TONIGHT.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS WILL PREVAIL.
&&
.MARINE...
A SOMEWHAT VARIABLE OR EVEN OFFSHORE FLOW WILL BECOME MORE
SOUTHERLY AS THE DAY PROGRESSES...WITH A WEAK LEE-SIDE TROUGH
EXPECTED TO PERSIST JUST INLAND FROM THE COAST AND A DISSIPATING
COLD FRONT REMAINING WELL INLAND. THE LACK OF A STRONG GRADIENT
SHOULD KEEP WINDS GENERALLY AROUND 10 KT OR LESS OVER THE COASTAL
WATERS TODAY AND TONIGHT WITH SEAS 3 FT OR LESS.
A FAIRLY TRANQUIL PERIOD IS EXPECTED FROM FRIDAY THROUGH MONDAY
AS A WEAK PRESSURE GRADIENT DOMINATES AND RESULTS IN MAINLY
SOUTHERLY TO SOUTHWESTERLY WINDS AT OR BELOW 15 KNOTS. SEAS WILL
BE AOB 3 FEET WITHIN 20 MILES OF THE COAST AND AOB 4 FEET IN
AMZ374.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
JAQ
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000
FXUS62 KCAE 241415
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
1015 AM EDT THU JUL 24 2008
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN TODAY AND FRIDAY AHEAD OF ANOTHER
COLD FRONT THAT WILL REACH THE AREA LATE SATURDAY OR SUNDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE ALONG WITH DRIER AIR WILL CONTINUE TO BUILD INTO THE
REGION THIS AFTERNOON. SATELLITE IMAGERY SHOWS SOME REMAINING FOG
AND LOW LEVEL CLOUDINESS ALONG THE EASTERN MIDLANDS AND COASTAL
AREAS WHICH SHOULD BURN OFF OVER THE NEXT HOUR OR TWO. EXPECT
MOSTLY SUNNY SKIES THROUGH THE AFTERNOON WITH LIGHT WINDS. HAVE
LOWERED DEWPOINTS SEVERAL DEGREES TO ACCOUNT FOR THE DRIER AIR AND
LOWERED CLOUD COVERAGE. UPDATE OUT SHORTLY FOR CHANGES NOTED AND
TO REMOVE MENTION OF FOG.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
COLD FRONT WILL REACH THE COAST THIS MORNING THEN STALL OFF THE
COAST THIS EVENING AND INTO FRIDAY. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT THROUGH FRIDAY. DRY AIRMASS IN PLACE WILL KEEP
POPS LOW THROUGH THE PERIOD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
GFS HAS A LITTLE DEEPER UPPER LEVEL TROF OVER THE AREA DURING THE
PERIOD SUGGESTING A BETTER THREAT FOR AIRMASS THUNDERSTORMS.
HOWEVER, NAM HAS BEEN PERFORMING BETTER LATELY AND LIFTS THE
COASTAL TROF FURTHER N WITH THE H5 RIDGE NUDGING FURTHER EAST INTO
THE AREA THROUGH SATURDAY BUT THEN BRINGS A DIGGING S/WV INTO THE
TN VLY SUNDAY INTO MONDAY. WILL HAVE SLIGHT CHC POPS FOR SAT AND
CHC POPS SUN/MON. TEMPS FOR THE WEEKEND WILL BE SLIGHTLY ABOVE
CLIMATOLOGY BUT WILL BE BACK TO NORMAL MONDAY THROUGH WEDNESDAY.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AREAS OF FOG AND STRATUS THAT DEVELOPED EARLY THIS MORNING WILL
DISSIPATE BY MID MORNING. OTHERWISE...EXPECT VFR CONDITIONS
TODAY...AS DRIER AIR FILTERS IN BEHIND A FRONT.
EXTENDED OUTLOOK...NO SIGNIFICANT IMPACTS TO AVIATION EXPECTED
THURSDAY THROUGH MONDAY.
$$
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
000
FXUS62 KCHS 241134
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
722 AM EDT THU JUL 24 2008
.SYNOPSIS...
A WEAK COLD FRONT WILL STALL OUT WEST OF THE AREA TODAY AND
DISSIPATE TONIGHT. HIGH PRESSURE WILL EXTEND ACROSS THE REGION
THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY MORNING SURFACE ANALYSIS SHOWS A WEAKENING COLD FRONT
MOVING THROUGH THE WESTERN CAROLINAS AND NORTHERN GEORGIA WITH A
PRONOUNCED LEE-SIDE TROUGH STRETCHING FROM CENTRAL GEORGIA THROUGH
THE CENTRAL MIDLANDS AND INTO EASTERN NORTH CAROLINA. ISOLATED
SHOWERS PERSIST ACROSS THE EASTERN MIDLANDS WHERE LOW-LEVEL
CONVERGENCE IS BEING ENHANCED BY A WEAK MESO-LOW THAT HAS FORMED
BETWEEN AUGUSTA AND COLUMBIA. THIS ACTIVITY HAS SHOWN SIGNS OF
WEAKENING DURING THE PAST HOUR BUT A BRIEF SHOWER CAN NOT BE RULED
OUT FROM HAMPTON COUNTY UP TO BERKELEY COUNTY THROUGH SUNRISE. THE
LEE-SIDE TROUGH AND EMBEDDED MESO LOW WILL DRIFT TO THE COAST
TODAY AS THE COLD FRONT MEANDERS EAST AND EVENTUALLY STALLS OUT
ACROSS THE EASTERN MIDLANDS AND THE CENTRAL SAVANNAH RIVER AREA.
THE PROSPECTS FOR MEASURABLE RAINFALL LOOKS RATHER BLEAK TODAY AS
THE UPPER TROUGH CURRENTLY MOVING ACROSS THE CAROLINAS IS FORECAST
TO SHIFT OFFSHORE BY SUNRISE. WEAK DNVA IN THE WAKE OF THE UPPER
TROUGH COUPLED WITH EXTENSIVE/DEEP DRY AIR THAT IS PROPAGATING
QUICKLY IN FROM THE WEST /PER WATER VAPOR TRENDS/ WILL TEND TO
CURTAIL CONVECTION DESPITE TEMPERATURES RISING INTO THE LOWER 90S.
PLAN TO MAINTAIN SLIGHT CHANCE POPS FROM MID AFTERNOON INTO EARLY
EVENING EXCEPT FOR THE FAR INTERIOR CORRIDOR FROM MILLEN AND
ALLENDALE OVER TO SMOAKS AND HARLEYVILLE WHERE POPS WILL REMAIN
LESS THAN 15 PERCENT. THIS REGIME IS SUPPORTED BY BOTH THE
GFS...THE SREF MEAN AND TO SOME EXTENT THE NAM...BUT THE NAM MASS
FIELDS APPEAR TO BE HEAVILY CONTAMINATED BY CONVECTIVE FEEDBACK
ALONG THE SEA BREEZE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
ANY LINGERING EVENING CONVECTION WILL QUICKLY DISSIPATE AFTER
SUNSET. WET GROUNDS FROM RECENT RAINFALLS...EXTENSIVE MID-LEVEL
DRY AIR AND LIGHT/CALM WINDS WILL SUPPORT THE DEVELOPMENT OF
PATCHY FOG AFTER MIDNIGHT. LOWS WILL RANGE FROM AROUND 70 WELL
INLAND TO THE UPPER 70S AT THE BEACHES.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY TROUGH WEDNESDAY WILL BE DOMINATED BY WEAK NORTHWESTERLY
FLOW ALOFT BETWEEN THE SOUTHERN PLAINS UPPER RIDGE AND AN UPPER
LEVEL TROUGH OVER THE GREAT LAKES/NORTHEASTERN STATES. AT THE
SURFACE...LEE SIDE TROUGHING MAINLY FROM CENTRAL NORTH CAROLINA TO
CENTRAL GEORGIA WILL BE COMMON.
BIGGEST CHALLENGE THIS FORECAST PERIOD IS THE POPS FOR FRIDAY AND
SATURDAY. ETA MOS AND GFS MOS ARE NOW IN AGREEMENT THAT POPS WILL BE
AT OR BELOW 10 PERCENT IN JUST ABOUT ALL AREAS BOTH DAYS. BASED ON
FORECAST SOUNDINGS...THIS SEEMS REASONABLE GIVEN DECENT CAP WITH 700
MB TEMPERATURES NEAR 8 CELSIUS AND DRY AIR ALOFT ESPECIALLY ON
FRIDAY. ADJUSTED POPS DOWN ON BOTH DAYS FROM THE PREVIOUS
FORECAST...BUT KEPT THEM ABOVE GUIDANCE ENOUGH TO MAINTAIN SLIGHT
CHANCE POPS BOTH AFTERNOONS. HAVE SOME CONCERN THAT THE MODELS
MAINTAIN THE DRIER AIR ALOFT TOO LONG AND THIS RESULTS IN LOWER POPS
THAN WOULD NORMALLY BE THE CASE. IN ADDITION...HAVE SOME CONCERN
THAT THERE WILL BE ENOUGH CONVERGENCE ALONG THE SEA BREEZE TO
OVERCOME THE CAP IN A FEW LOCATIONS BOTH DAYS.
DEEPER MOISTURE IS EXPECTED TO RETURN SATURDAY NIGHT AND REMAIN WITH
US THROUGH AT LEAST WEDNESDAY. THIS COMBINED WITH SURFACE DEWPOINTS
AT LEAST IN THE LOWER TO MID 70S AND UPPER LEVEL DISTURBANCES MOVING
ACROSS THE AREA SHOULD BE ENOUGH TO RESULT IN MAINLY SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
KCHS - PATCHY GROUND FOG LURKING AROUND THE ASOS VISIBILITY SENSOR
WILL QUICKLY BURN OFF BY 12Z. WE ARE CAREFULLY WATCHING AN
EXPANDING AREA OF STRATUS THAT IS WORKING SLOWLY SOUTH FROM THE PEE
DEE REGION THIS MORNING. THE MONCKS CORNER ASOS HAS BEEN REPORTING
SCT006 FOR THE PAST HOUR OR SO WHILE FARTHER NORTH CEILINGS HAVE
BEEN AROUND 400-600 FT. NOW THAT THE SUN IS UP EXPECT THE STRATUS TO
SLOWLY BURN OFF OVER THE NEXT FEW HOURS SO NO MENTION WILL BE
INCLUDED WITH THE 12Z TAF SET. THIS WILL BE CAREFULLY MONITORED
HOWEVER. OTHERWISE EXPECT VFR CONDITIONS TO PREVAIL. COULD SEE SOME
PATCHY GROUND FOG DEVELOP AGAIN TONIGHT.
KSAV - SATELLITE IMAGERY SHOWS THE BAND OF LOW CLOUDS WHICH HAS
PLAGUED THE SAV TERMINAL SINCE 10Z IS SHOWING SIGNS OF
DISSIPATING. WILL CARRY MVFR CIGS AROUND 1500 FT THROUGH 13Z WITH
A QUICK IMPROVEMENT TO VFR THEREAFTER. PATCHY GROUND FOG
COULD DEVELOP AGAIN TONIGHT.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS WILL PREVAIL.
&&
.MARINE...
WINDS ACROSS THE SOUTH CAROLINA WATERS ARE BEING HEAVILY
INFLUENCES BY CONVECTION THAT IS LINGERING OFF THE CHARLESTON
COUNTY. THESE INFLUENCES SHOULD DIMINISH OVER THE NEXT FEW HOURS
AS THE CONVECTIVE COMPLEX PUSHES FARTHER OFFSHORE. ACROSS THE
GEORGIA WATERS...A BIT OF A SURGE CONTINUES BUT SPEEDS HAVE
RECENTLY DROPPED BELOW SMALL CRAFT ADVISORY CRITERIA. WILL
THEREFORE CANCEL THE ADVISORY A FEW HOURS EARLY. OTHERWISE EXPECT
WINDS TO RECOVER MORE SOUTHERLY TODAY AS A COLD FRONT REMAINS WELL
TO THE WEST AND A WEAK LEE-SIDE TROUGH MEANDERS JUST INLAND FROM
THE COAST. SOUTHERLY WINDS WILL PERSIST INTO TONIGHT BUT BOTH
SPEEDS AND THE RESULTING SEAS WILL REMAIN WELL BELOW ADVISORY
CRITERIA.
A FAIRLY TRANQUIL PERIOD IS EXPECTED FROM FRIDAY THROUGH MONDAY
AS A WEAK PRESSURE GRADIENT DOMINATES AND RESULTS IN MAINLY
SOUTHERLY TO SOUTHWESTERLY WINDS AT OR BELOW 15 KNOTS. SEAS WILL
BE AOB 3 FEET WITHIN 20 MILES OF THE COAST AND AOB 4 FEET IN
AMZ374.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
000
FXUS62 KCAE 241129
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
729 AM EDT THU JUL 24 2008
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN TODAY AND FRIDAY AHEAD OF ANOTHER
COLD FRONT THAT WILL REACH THE AREA LATE SATURDAY OR SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE BEGINING TO BUILD IN FROM THE NORTHWEST. SURFACE
COLD FRONT SHOULD BE EAST OF THE AREA BY 12Z. PATCHY FOG.
&&
.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
COLD FRONT WILL REACH THE COAST THIS MORNING THEN STALL OFF THE
COAST THIS EVENING AND INTO FRIDAY. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT THROUGH FRIDAY. DRY AIRMASS IN PLACE WILL KEEP
POPS LOW THROUGH THE PERIOD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
GFS HAS A LITTLE DEEPER UPPER LEVEL TROF OVER THE AREA DURING THE
PERIOD SUGGESTING A BETTER THREAT FOR AIRMASS THUNDERSTORMS.
HOWEVER, NAM HAS BEEN PERFORMING BETTER LATELY AND LIFTS THE
COASTAL TROF FURTHER N WITH THE H5 RIDGE NUDGING FURTHER EAST INTO
THE AREA THROUGH SATURDAY BUT THEN BRINGS A DIGGING S/WV INTO THE
TN VLY SUNDAY INTO MONDAY. WILL HAVE SLIGHT CHC POPS FOR SAT AND
CHC POPS SUN/MON. TEMPS FOR THE WEEKEND WILL BE SLIGHTLY ABOVE
CLIMATOLOGY BUT WILL BE BACK TO NORMAL MONDAY THROUGH WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AREAS OF FOG AND STRATUS THAT DEVELOPED EARLY THIS MORNING WILL
DISSIPATE BY MID MORNING. OTHERWISE...EXPECT VFR CONDITIONS
TODAY...AS DRIER AIR FILTERS IN BEHIND A FRONT.
EXTENDED OUTLOOK...NO SIGNIFICANT IMPACTS TO AVIATION EXPECTED
THURSDAY THROUGH MONDAY.
$$
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCHS 241122
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
722 AM EDT THU JUL 24 2008
.SYNOPSIS...
A WEAK COLD FRONT WILL STALL OUT WEST OF THE AREA TODAY AND
DISSIPATE TONIGHT. HIGH PRESSURE WILL EXTEND ACROSS THE REGION
THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY MORNING SURFACE ANALYSIS SHOWS A WEAKENING COLD FRONT
MOVING THROUGH THE WESTERN CAROLINAS AND NORTHERN GEORGIA WITH A
PRONOUNCED LEE-SIDE TROUGH STRETCHING FROM CENTRAL GEORGIA THROUGH
THE CENTRAL MIDLANDS AND INTO EASTERN NORTH CAROLINA. ISOLATED
SHOWERS PERSIST ACROSS THE EASTERN MIDLANDS WHERE LOW-LEVEL
CONVERGENCE IS BEING ENHANCED BY A WEAK MESO-LOW THAT HAS FORMED
BETWEEN AUGUSTA AND COLUMBIA. THIS ACTIVITY HAS SHOWN SIGNS OF
WEAKENING DURING THE PAST HOUR BUT A BRIEF SHOWER CAN NOT BE RULED
OUT FROM HAMPTON COUNTY UP TO BERKELEY COUNTY THROUGH SUNRISE. THE
LEE-SIDE TROUGH AND EMBEDDED MESO LOW WILL DRIFT TO THE COAST
TODAY AS THE COLD FRONT MEANDERS EAST AND EVENTUALLY STALLS OUT
ACROSS THE EASTERN MIDLANDS AND THE CENTRAL SAVANNAH RIVER AREA.
THE PROSPECTS FOR MEASURABLE RAINFALL LOOKS RATHER BLEAK TODAY AS
THE UPPER TROUGH CURRENTLY MOVING ACROSS THE CAROLINAS IS FORECAST
TO SHIFT OFFSHORE BY SUNRISE. WEAK DNVA IN THE WAKE OF THE UPPER
TROUGH COUPLED WITH EXTENSIVE/DEEP DRY AIR THAT IS PROPAGATING
QUICKLY IN FROM THE WEST /PER WATER VAPOR TRENDS/ WILL TEND TO
CURTAIL CONVECTION DESPITE TEMPERATURES RISING INTO THE LOWER 90S.
PLAN TO MAINTAIN SLIGHT CHANCE POPS FROM MID AFTERNOON INTO EARLY
EVENING EXCEPT FOR THE FAR INTERIOR CORRIDOR FROM MILLEN AND
ALLENDALE OVER TO SMOAKS AND HARLEYVILLE WHERE POPS WILL REMAIN
LESS THAN 15 PERCENT. THIS REGIME IS SUPPORTED BY BOTH THE
GFS...THE SREF MEAN AND TO SOME EXTENT THE NAM...BUT THE NAM MASS
FIELDS APPEAR TO BE HEAVILY CONTAMINATED BY CONVECTIVE FEEDBACK
ALONG THE SEA BREEZE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
ANY LINGERING EVENING CONVECTION WILL QUICKLY DISSIPATE AFTER
SUNSET. WET GROUNDS FROM RECENT RAINFALLS...EXTENSIVE MID-LEVEL
DRY AIR AND LIGHT/CALM WINDS WILL SUPPORT THE DEVELOPMENT OF
PATCHY FOG AFTER MIDNIGHT. LOWS WILL RANGE FROM AROUND 70 WELL
INLAND TO THE UPPER 70S AT THE BEACHES.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY TROUGH WEDNESDAY WILL BE DOMINATED BY WEAK NORTHWESTERLY
FLOW ALOFT BETWEEN THE SOUTHERN PLAINS UPPER RIDGE AND AN UPPER
LEVEL TROUGH OVER THE GREAT LAKES/NORTHEASTERN STATES. AT THE
SURFACE...LEE SIDE TROUGHING MAINLY FROM CENTRAL NORTH CAROLINA TO
CENTRAL GEORGIA WILL BE COMMON.
BIGGEST CHALLENGE THIS FORECAST PERIOD IS THE POPS FOR FRIDAY AND
SATURDAY. ETA MOS AND GFS MOS ARE NOW IN AGREEMENT THAT POPS WILL BE
AT OR BELOW 10 PERCENT IN JUST ABOUT ALL AREAS BOTH DAYS. BASED ON
FORECAST SOUNDINGS...THIS SEEMS REASONABLE GIVEN DECENT CAP WITH 700
MB TEMPERATURES NEAR 8 CELSIUS AND DRY AIR ALOFT ESPECIALLY ON
FRIDAY. ADJUSTED POPS DOWN ON BOTH DAYS FROM THE PREVIOUS
FORECAST...BUT KEPT THEM ABOVE GUIDANCE ENOUGH TO MAINTAIN SLIGHT
CHANCE POPS BOTH AFTERNOONS. HAVE SOME CONCERN THAT THE MODELS
MAINTAIN THE DRIER AIR ALOFT TOO LONG AND THIS RESULTS IN LOWER POPS
THAN WOULD NORMALLY BE THE CASE. IN ADDITION...HAVE SOME CONCERN
THAT THERE WILL BE ENOUGH CONVERGENCE ALONG THE SEA BREEZE TO
OVERCOME THE CAP IN A FEW LOCATIONS BOTH DAYS.
DEEPER MOISTURE IS EXPECTED TO RETURN SATURDAY NIGHT AND REMAIN WITH
US THROUGH AT LEAST WEDNESDAY. THIS COMBINED WITH SURFACE DEWPOINTS
AT LEAST IN THE LOWER TO MID 70S AND UPPER LEVEL DISTURBANCES MOVING
ACROSS THE AREA SHOULD BE ENOUGH TO RESULT IN MAINLY SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
KCHS - PATCHY GROUND FOG LURKING AROUND THE ASOS VISIBILITY SENSOR
WILL QUICKLY BURN OFF BY 12Z. WE ARE CAREFULLY WATCHING AN
EXPANDING AREA OF STRATUS THAT IS WORKING SLOWLY SOUTH FROM THE
PEE REGION THIS MORNING. THE MONCKS CORNER ASOS HAS BEEN REPORTING
SCT006 FOR THE PAST HOUR OR SO WHILE FARTHER NORTH CEILINGS HAVE
BEEN AROUND 400-600 FT. NOW THAT THE SUN IS UP EXPECT THE STRATUS
TO SLOWLY BURN OFF OVER THE NEXT FEW HOURS SO NO MENTION WILL BE
INCLUDED WITH THE 12Z TAF SET. THIS WILL BE CAREFULLY MONITORED
HOWEVER. OTHERWISE EXPECT VFR CONDITIONS TO PREVAIL. COULD SEE
SOME PATCHY GROUND FOG DEVELOP AGAIN TONIGHT.
KSAV - SATELLITE IMAGERY SHOWS THE BAND OF LOW CLOUDS WHICH HAS
PLAGUED THE SAV TERMINAL SINCE 10Z IS SHOWING SIGNS OF
DISSIPATING. WILL CARRY MVFR CIGS AROUND 1500 FT THROUGH 13Z WITH
A QUICK IMPROVEMENT TO VFR THEREAFTER. PATCHY GROUND FOG
COULD DEVELOP AGAIN TONIGHT.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS WILL PREVAIL.
&&
.MARINE...
WINDS ACROSS THE SOUTH CAROLINA WATERS ARE BEING HEAVILY
INFLUENCES BY CONVECTION THAT IS LINGERING OFF THE CHARLESTON
COUNTY. THESE INFLUENCES SHOULD DIMINISH OVER THE NEXT FEW HOURS
AS THE CONVECTIVE COMPLEX PUSHES FARTHER OFFSHORE. ACROSS THE
GEORGIA WATERS...A BIT OF A SURGE CONTINUES BUT SPEEDS HAVE
RECENTLY DROPPED BELOW SMALL CRAFT ADVISORY CRITERIA. WILL
THEREFORE CANCEL THE ADVISORY A FEW HOURS EARLY. OTHERWISE EXPECT
WINDS TO RECOVER MORE SOUTHERLY TODAY AS A COLD FRONT REMAINS WELL
TO THE WEST AND A WEAK LEE-SIDE TROUGH MEANDERS JUST INLAND FROM
THE COAST. SOUTHERLY WINDS WILL PERSIST INTO TONIGHT BUT BOTH
SPEEDS AND THE RESULTING SEAS WILL REMAIN WELL BELOW ADVISORY
CRITERIA.
A FAIRLY TRANQUIL PERIOD IS EXPECTED FROM FRIDAY THROUGH MONDAY
AS A WEAK PRESSURE GRADIENT DOMINATES AND RESULTS IN MAINLY
SOUTHERLY TO SOUTHWESTERLY WINDS AT OR BELOW 15 KNOTS. SEAS WILL
BE AOB 3 FEET WITHIN 20 MILES OF THE COAST AND AOB 4 FEET IN
AMZ374.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
[top]
000
FXUS62 KFFC 240940
AFDFFC
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
539 AM EDT THU JUL 24 2008
.SHORT TERM /TODAY THROUGH SATURDAY/...
CURRENT SATELLITE LOOP SHOWS CLOUDS CLEARING THE AREA AS FRONTAL
BOUNDARY PUSHES INTO N GA. THE MODELS ARE ALL SHOWING THIS FRONT
MOVING SOUTH THROUGH THE STATE TODAY. THIS FRONT IS EXPECTED TO MOVE
ALL THE WAY INTO N FL BUT IT IT VERY HARD FOR FRONTS TO MAKE IT THAT
FAR SOUTH THIS TIME OF YEAR. THINKING THIS FRONT WILL STALL
SOMEWHERE ACROSS S GA TONIGHT. WILL KEEP SLIGHT CHANCE POPS IN
ACROSS THE SOUTHERN CWA FOR THIS AFTERNOON. A WEAK RIDGE OF HIGH
PRESSURE BUILD IN JUST BEHIND THIS FRONT TODAY AND STAYS OVER THE
AREA THROUGH FRI. THIS RIDGE SHOULD KEEP MOST OFF NORTH AND CENTRAL
GA DRY TODAY AND FRI BUT ANOTHER WAVE PUSHES SE OUT OF THE MID MS
VALLEY TODAY AND INTO N AL/N GA BY 18Z FRI - 00Z SAT. MOS GUIDANCE
ONCE TO KEEP THE AREA DRY FRI BUT HAVE PUT IN A SLIGHT CHANCE FOR N
AND WESTERN SECTIONS OF THE STATE. THIS WAVE WILL MAKE ITS WAY
ACROSS THE AREA SAT BRINGING MORE SHRA/TSRA TO THE REGION. STAYED
CLOSE TO MOS ON TEMPERATURES THROUGH THE SHORT TERM.
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE PATTERN LOOKS TO REMAIN CONSISTENT THROUGH THE EXTENDED PERIOD
WITH WAVES MOVING SE IN THE UPPER LEVEL NW FLOW. THE MODELS SHOW A
FRONT STALLING ACROSS S GA SAT NIGHT/SUN AND THEN ANOTHER ONE MOVES
INTO THE AREA TUE. WILL KEEP A CHANCE OF AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE EXTENDED. NORTHWEST
FLOW WILL KEEP TEMPERATURES NEAR SEASONAL NORMS AS WELL.
01
&&
.AVIATION...
GPS PRECIPITABLE WATER MEASUREMENTS FROM ATL INDICATING THAT AIRMASS
CONTINUES TO DRY QUICKLY THIS MORNING...THOUGH RESIDUAL LOW LEVEL
MOISTURE STILL HANGING ON FOR THE NEXT FEW HOURS. FRONTAL BOUNDARY
JUST NORTH OF AN RYY TO AHN LINE WITH A NARROW BAND OF LOW STRATUS
IMMEDIATELY POST-FRONTAL. THE 09Z OBSERVATION AT VPC WAS ONLY SITE
INDICATING FEW006...SO DO NOT ANTICIPATE CLOUD COVERAGE WILL BE
GREAT ENOUGH TO REACH IFR. VISIBILITIES DOWN TO AN MVFR 3-5SM IN
SPOTS ALONG AND AHEAD OF THE FRONT ACROSS N GA...THOUGH ATL SHOULD
REMAIN 6SM OR BETTER THROUGH THE MORNING. DRIER AIR IS PUSHING INTO
EXTREME N GA THIS MORNING AS HIGH PRESSURE BUILDS IN. AS AIRMASS
BEGINS TO MIX MORE DEEPLY BY LATE MORNING...ANY CLOUD DECK SHOULD
QUICKLY LIFT/DISSIPATE. EXPECT SKC/SCT250 THROUGH MUCH OF THE NEXT
24 HOURS AS DRYING LIGHT NW WINDS CONTINUE.
RRH
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 93 64 93 69 91 / 0 5 10 10 30
ATLANTA 90 68 92 69 89 / 0 5 10 10 30
BLAIRSVILLE 88 61 85 63 85 / 5 5 20 20 40
CARTERSVILLE 89 60 91 67 89 / 5 5 20 10 40
COLUMBUS 90 70 94 71 92 / 20 0 20 10 30
GAINESVILLE 91 67 90 69 88 / 5 5 10 20 30
MACON 94 68 97 71 95 / 10 0 10 10 30
ROME 91 62 92 69 91 / 5 5 20 20 40
PEACHTREE CITY 91 61 92 65 89 / 5 0 10 10 30
VIDALIA 94 70 96 70 96 / 20 0 10 10 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
000
FXUS62 KCAE 240809 AAA
AFDCAE
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE COLUMBIA SC
409 AM EDT THU JUL 24 2008
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN TODAY AND FRIDAY AHEAD OF ANOTHER
COLD FRONT THAT WILL REACH THE AREA LATE SATURDAY OR SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
HIGH PRESSURE BEGINING TO BUILD IN FROM THE NORTHWEST. SURFACE
COLD FRONT SHOULD BE EAST OF THE AREA BY 12Z. PATCHY FOG.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
COLD FRONT WILL REACH THE COAST THIS MORNING THEN STALL OFF THE
COAST THIS EVENING AND INTO FRIDAY. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT THROUGH FRIDAY. DRY AIRMASS IN PLACE WILL KEEP
POPS LOW THROUGH THE PERIOD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
GFS HAS A LITTLE DEEPER UPPER LEVEL TROF OVER THE AREA DURING THE
PERIOD SUGGESTING A BETTER THREAT FOR AIRMASS THUNDERSTORMS.
HOWEVER, NAM HAS BEEN PERFORMING BETTER LATELY AND LIFTS THE
COASTAL TROF FURTHER N WITH THE H5 RIDGE NUDGING FURTHER EAST INTO
THE AREA THROUGH SATURDAY BUT THEN BRINGS A DIGGING S/WV INTO THE
TN VLY SUNDAY INTO MONDAY. WILL HAVE SLIGHT CHC POPS FOR SAT AND
CHC POPS SUN/MON. TEMPS FOR THE WEEKEND WILL BE SLIGHTLY ABOVE
CLIMATOLOGY BUT WILL BE BACK TO NORMAL MONDAY THROUGH WEDNESDAY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
WILL EXPECT ANY REMAINING SHOWER ACTIVITY TO DISSIPATE TOWARDS
DAYBREAK. AREA OF HIGH LEVEL CLOUDINESS WILL CLEAR OUT BY DAYBREAK
AS WELL. THIS WILL LEAD TO SOME FOG OR STRATUS POSSIBILITIES FOR
TAF SITES. DRIER AIR AND HIGH PRESSURE WILL FILTER IN LATER
TODAY...WITH NE WINDS...AND LITTLE CLOUD COVER.
EXTENDED OUTLOOK...NO SIGNIFICANT IMPACTS TO AVIATION EXPECTED
THURSDAY THROUGH MONDAY.
$$
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KFFC 240748
AFDFFC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
348 AM EDT THU JUL 24 2008
.SHORT TERM /TODAY THROUGH SATURDAY/...
CURRENT SATELLITE LOOP SHOWS CLOUDS CLEARING THE AREA AS FRONTAL
BOUNDARY PUSHES INTO N GA. THE MODELS ARE ALL SHOWING THIS FRONT
MOVING SOUTH THROUGH THE STATE TODAY. THIS FRONT IS EXPECTED TO MOVE
ALL THE WAY INTO N FL BUT IT IT VERY HARD FOR FRONTS TO MAKE IT THAT
FAR SOUTH THIS TIME OF YEAR. THINKING THIS FRONT WILL STALL
SOMEWHERE ACROSS S GA TONIGHT. WILL KEEP SLIGHT CHANCE POPS IN
ACROSS THE SOUTHERN CWA FOR THIS AFTERNOON. A WEAK RIDGE OF HIGH
PRESSURE BUILD IN JUST BEHIND THIS FRONT TODAY AND STAYS OVER THE
AREA THROUGH FRI. THIS RIDGE SHOULD KEEP MOST OFF NORTH AND CENTRAL
GA DRY TODAY AND FRI BUT ANOTHER WAVE PUSHES SE OUT OF THE MID MS
VALLEY TODAY AND INTO N AL/N GA BY 18Z FRI - 00Z SAT. MOS GUIDANCE
ONCE TO KEEP THE AREA DRY FRI BUT HAVE PUT IN A SLIGHT CHANCE FOR N
AND WESTERN SECTIONS OF THE STATE. THIS WAVE WILL MAKE ITS WAY
ACROSS THE AREA SAT BRINGING MORE SHRA/TSRA TO THE REGION. STAYED
CLOSE TO MOS ON TEMPERATURES THROUGH THE SHORT TERM.
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE PATTERN LOOKS TO REMAIN CONSISTENT THROUGH THE EXTENDED PERIOD
WITH WAVES MOVING SE IN THE UPPER LEVEL NW FLOW. THE MODELS SHOW A
FRONT STALLING ACROSS S GA SAT NIGHT/SUN AND THEN ANOTHER ONE MOVES
INTO THE AREA TUE. WILL KEEP A CHANCE OF AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS EACH DAY THROUGH THE EXTENDED. NORTHWEST
FLOW WILL KEEP TEMPERATURES NEAR SEASONAL NORMS AS WELL.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 93 64 93 69 91 / 0 5 10 10 30
ATLANTA 90 68 92 69 89 / 0 5 10 10 30
BLAIRSVILLE 88 61 85 63 85 / 5 5 20 20 40
CARTERSVILLE 89 60 91 67 89 / 5 5 20 10 40
COLUMBUS 90 70 94 71 92 / 20 0 20 10 30
GAINESVILLE 91 67 90 69 88 / 5 5 10 20 30
MACON 94 68 97 71 95 / 10 0 10 10 30
ROME 91 62 92 69 91 / 5 5 20 20 40
PEACHTREE CITY 91 61 92 65 89 / 5 0 10 10 30
VIDALIA 94 70 96 70 96 / 20 0 10 10 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
000
FXUS62 KCHS 240728
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
328 AM EDT THU JUL 24 2008
.SYNOPSIS...
A WEAK COLD FRONT WILL STALL OUT WEST OF THE AREA TODAY AND
DISSIPATE TONIGHT. HIGH PRESSURE WILL EXTEND ACROSS THE REGION
THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
EARLY MORNING SURFACE ANALYSIS SHOWS A WEAKENING COLD FRONT
MOVING THROUGH THE WESTERN CAROLINAS AND NORTHERN GEORGIA WITH A
PRONOUNCED LEE-SIDE TROUGH STRETCHING FROM CENTRAL GEORGIA THROUGH
THE CENTRAL MIDLANDS AND INTO EASTERN NORTH CAROLINA. ISOLATED
SHOWERS PERSIST ACROSS THE EASTERN MIDLANDS WHERE LOW-LEVEL
CONVERGENCE IS BEING ENHANCED BY A WEAK MESO-LOW THAT HAS FORMED
BETWEEN AUGUSTA AND COLUMBIA. THIS ACTIVITY HAS SHOWN SIGNS OF
WEAKENING DURING THE PAST HOUR BUT A BRIEF SHOWER CAN NOT BE RULED
OUT FROM HAMPTON COUNTY UP TO BERKELEY COUNTY THROUGH SUNRISE. THE
LEE-SIDE TROUGH AND EMBEDDED MESO LOW WILL DRIFT TO THE COAST
TODAY AS THE COLD FRONT MEANDERS EAST AND EVENTUALLY STALLS OUT
ACROSS THE EASTERN MIDLANDS AND THE CENTRAL SAVANNAH RIVER AREA.
THE PROSPECTS FOR MEASURABLE RAINFALL LOOKS RATHER BLEAK TODAY AS
THE UPPER TROUGH CURRENTLY MOVING ACROSS THE CAROLINAS IS FORECAST
TO SHIFT OFFSHORE BY SUNRISE. WEAK DNVA IN THE WAKE OF THE UPPER
TROUGH COUPLED WITH EXTENSIVE/DEEP DRY AIR THAT IS PROPAGATING
QUICKLY IN FROM THE WEST /PER WATER VAPOR TRENDS/ WILL TEND TO
CURTAIL CONVECTION DESPITE TEMPERATURES RISING INTO THE LOWER 90S.
PLAN TO MAINTAIN SLIGHT CHANCE POPS FROM MID AFTERNOON INTO EARLY
EVENING EXCEPT FOR THE FAR INTERIOR CORRIDOR FROM MILLEN AND
ALLENDALE OVER TO SMOAKS AND HARLEYVILLE WHERE POPS WILL REMAIN
LESS THAN 15 PERCENT. THIS REGIME IS SUPPORTED BY BOTH THE
GFS...THE SREF MEAN AND TO SOME EXTENT THE NAM...BUT THE NAM MASS
FIELDS APPEAR TO BE HEAVILY CONTAMINATED BY CONVECTIVE FEEDBACK
ALONG THE SEA BREEZE.
&&
.SHORT TERM /TONIGHT/...
ANY LINGERING EVENING CONVECTION WILL QUICKLY DISSIPATE AFTER
SUNSET. WET GROUNDS FROM RECENT RAINFALLS...EXTENSIVE MID-LEVEL
DRY AIR AND LIGHT/CALM WINDS WILL SUPPORT THE DEVELOPMENT OF
PATCHY FOG AFTER MIDNIGHT. LOWS WILL RANGE FROM AROUND 70 WELL
INLAND TO THE UPPER 70S AT THE BEACHES.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY TROUGH WEDNESDAY WILL BE DOMINATED BY WEAK NORTHWESTERLY
FLOW ALOFT BETWEEN THE SOUTHERN PLAINS UPPER RIDGE AND AN UPPER
LEVEL TROUGH OVER THE GREAT LAKES/NORTHEASTERN STATES. AT THE
SURFACE...LEE SIDE TROUGHING MAINLY FROM CENTRAL NORTH CAROLINA TO
CENTRAL GEORGIA WILL BE COMMON.
BIGGEST CHALLENGE THIS FORECAST PERIOD IS THE POPS FOR FRIDAY AND
SATURDAY. ETA MOS AND GFS MOS ARE NOW IN AGREEMENT THAT POPS WILL BE
AT OR BELOW 10 PERCENT IN JUST ABOUT ALL AREAS BOTH DAYS. BASED ON
FORECAST SOUNDINGS...THIS SEEMS REASONABLE GIVEN DECENT CAP WITH 700
MB TEMPERATURES NEAR 8 CELSIUS AND DRY AIR ALOFT ESPECIALLY ON
FRIDAY. ADJUSTED POPS DOWN ON BOTH DAYS FROM THE PREVIOUS
FORECAST...BUT KEPT THEM ABOVE GUIDANCE ENOUGH TO MAINTAIN SLIGHT
CHANCE POPS BOTH AFTERNOONS. HAVE SOME CONCERN THAT THE MODELS
MAINTAIN THE DRIER AIR ALOFT TOO LONG AND THIS RESULTS IN LOWER POPS
THAN WOULD NORMALLY BE THE CASE. IN ADDITION...HAVE SOME CONCERN
THAT THERE WILL BE ENOUGH CONVERGENCE ALONG THE SEA BREEZE TO
OVERCOME THE CAP IN A FEW LOCATIONS BOTH DAYS.
DEEPER MOISTURE IS EXPECTED TO RETURN SATURDAY NIGHT AND REMAIN WITH
US THROUGH AT LEAST WEDNESDAY. THIS COMBINED WITH SURFACE DEWPOINTS
AT LEAST IN THE LOWER TO MID 70S AND UPPER LEVEL DISTURBANCES MOVING
ACROSS THE AREA SHOULD BE ENOUGH TO RESULT IN MAINLY SCATTERED
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
KCHS - THE MAIN LINE OF SHOWERS AND THUNDERSTORMS HAS PUSHED EAST
OF THE TERMINAL ALTHOUGH SOME ISOLATED ACTIVITY REMAINS ACROSS THE
MIDLANDS. THIS ACTIVITY IS EXPECTED TO DISSIPATE BEFORE REACHING
THE CHS AIRSPACE...BUT TRENDS WILL BE CAREFULLY WATCHED IN CASE AN
AMENDMENT IS NEEDED TO INCLUDE PCPN IN THE CHS TAF. MID-HIGH LEVEL
CLOUDINESS WILL GRADUALLY THIN OUT THIS MORNING BUT THERE SHOULD
BE ENOUGH PRECLUDE SIGNIFICANT FOG FORMATION THROUGH SUNRISE. THE
FOG POTENTIAL IS NOT NON-ZERO SINCE THE GROUNDS ARE WET FROM EARLIER
RAINS. WILL CARRY A TEMPO 5SM BR GROUP FROM 09-12Z TO COVER THIS
POSSIBILITY. OTHERWISE VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24
HOURS.
KSAV - EXTENSIVE MID-HIGH LEVEL CLOUDINESS REMAINS IN PLACE THIS
MORNING. SATELLITE AND SURFACE OBSERVATIONS INDICATE A BROKEN DECK
AROUND 4000-5000 FT IS SLOWLY EXPANDING IN COVERAGE FROM VDI-TBR.
THIS AREA OF ENHANCED CLOUD COVER SHOULD REACH THE SAV TERMINAL
BY 09Z AND REMAIN IN PLACE THROUGH SUNRISE. THIS SHOULD PRECLUDE
SIGNIFICANT FOG DEVELOPMENT SO FOG WILL BE REMOVED FROM THE SAV
TAF WITH THE 06Z CYCLE. VFR CONDITIONS WILL PREVAIL FOR THE NEXT
24 HOURS.
EXTENDED AVIATION OUTLOOK...A CHANCE OF MVFR VSBYS EACH MORNING
DUE TO HIGH LOW LEVEL MOISTURE AND LIGHT WINDS...OTHERWISE VFR
CONDITIONS EXPECTED OUTSIDE OF MAINLY AFTERNOON/EVENING CONVECTION.
&&
.MARINE...
WINDS ACROSS THE SOUTH CAROLINA WATERS ARE BEING HEAVILY
INFLUENCES BY CONVECTION THAT IS LINGERING OFF THE CHARLESTON
COUNTY. THESE INFLUENCES SHOULD DIMINISH OVER THE NEXT FEW HOURS
AS THE CONVECTIVE COMPLEX PUSHES FARTHER OFFSHORE. ACROSS THE
GEORGIA WATERS...A BIT OF A SURGE CONTINUES BUT SPEEDS HAVE
RECENTLY DROPPED BELOW SMALL CRAFT ADVISORY CRITERIA. WILL
THEREFORE CANCEL THE ADVISORY A FEW HOURS EARLY. OTHERWISE EXPECT
WINDS TO RECOVER MORE SOUTHERLY TODAY AS A COLD FRONT REMAINS WELL
TO THE WEST AND A WEAK LEE-SIDE TROUGH MEANDERS JUST INLAND FROM
THE COAST. SOUTHERLY WINDS WILL PERSIST INTO TONIGHT BUT BOTH
SPEEDS AND THE RESULTING SEAS WILL REMAIN WELL BELOW ADVISORY
CRITERIA.
A FAIRLY TRANQUIL PERIOD IS EXPECTED FROM FRIDAY THROUGH MONDAY
AS A WEAK PRESSURE GRADIENT DOMINATES AND RESULTS IN MAINLY
SOUTHERLY TO SOUTHWESTERLY WINDS AT OR BELOW 15 KNOTS. SEAS WILL
BE AOB 3 FEET WITHIN 20 MILES OF THE COAST AND AOB 4 FEET IN
AMZ374.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST/MTE
000
FXUS62 KCAE 240609
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
209 AM EDT THU JUL 24 2008
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN TODAY AND FRIDAY AHEAD OF ANOTHER
COLD FRONT THAT WILL REACH THE AREA LATE SATURDAY OR SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
HIGH PRESSURE BEGINING TO BUILD IN FROM THE NORTHWEST. SURFACE
COLD FRONT SHOULD BE EAST OF THE AREA BY 12Z. PATCHY FOG.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
COLD FRONT WILL REACH THE COAST THIS MORNING THEN STALL OFF THE
COAST THIS EVENING AND INTO FRIDAY. HIGH PRESSURE WILL BUILD IN
BEHIND THE FRONT THROUGH FRIDAY. DRY AIRMASS IN PLACE WILL KEEP
POPS LOW THROUGH THE PERIOD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
GFS HAS A LITTLE DEEPER UPPER LEVEL TROF OVER THE AREA DURING THE
PERIOD SUGGESTING A BETTER THREAT FOR AIRMASS THUNDERSTORMS.
HOWEVER, NAM HAS BEEN PERFORMING BETTER LATELY AND LIFTS THE
COASTAL TROF FURTHER N WITH THE H5 RIDGE NUDGING FURTHER EAST INTO
THE AREA THROUGH SATURDAY BUT THEN BRINGS A DIGGING S/WV INTO THE
TN VLY SUNDAY INTO MONDAY. WILL HAVE SLIGHT CHC POPS FOR SAT AND
CHC POPS SUN/MON. TEMPS FOR THE WEEKEND WILL BE SLIGHTLY ABOVE
CLIMATOLOGY BUT WILL BE BACK TO NORMAL MONDAY THROUGH WEDNESDAY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
BATCH OF SHOWERS AND THUNDERSTORMS JUST WEST OF CAE
CURRENTLY...MOVING SE. WILL EXPECT TSRA ACTIVITY TO GRADUALLY
DISSIPATE OR MOVE OUT OF THE FORECAST AREA LATER TONIGHT.
DRIER AIR AND HIGH PRESSURE WILL FILTER IN THURSDAY...WITH NE
WINDS...AND LITTLE CLOUD COVER.
EXTENDED OUTLOOK...NO SIGNIFICANT IMPACTS TO AVIATION EXPECTED
THURSDAY THROUGH MONDAY.
$$
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...02
NEAR TERM...02
SHORT TERM...02
LONG TERM...02
AVIATION...31
000
FXUS62 KCHS 240528
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
128 AM EDT THU JUL 24 2008
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT WILL
APPROACH FROM THE NORTHWEST OVERNIGHT. THE WEAKENING FRONT WILL
STALL JUST NORTHWEST OF THE AREA THURSDAY BEFORE DISSIPATING.
ATLANTIC HIGH PRESSURE WILL REMAIN THROUGH THE MIDDLE OF NEXT
WEEK...WITH WEAK LOW PRESSURE ACROSS INLAND AREAS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MULTICELL CLUSTERS OF THUNDERSTORMS WILL CONTINUE TO ADVANCE E/SE
ACROSS THE FORECAST AREA OVERNIGHT...EXITING TO THE E/NE LATE.
WILL CONTINUE TO DIVIDE POPS INTO TWO PERIODS...WITH POPS
INITIALLY TAPERED FROM CHANCE/LIKELY ACROSS THE NORTHERN 2/3 OF
THE FORECAST AREA TO SLIGHT CHANCE S...THEN...WILL GRADUATE POPS
FROM SLIGHT CHANCE/CHANCE N/NE TO POPS BELOW 15 PERCENT W/SW
FOR THE BALANCE OF THE NIGHT.
DUE TO MESOSCALE BOUNDARY INTERACTIONS AND RESIDUAL INSTABILITY CANNOT
RULE OUT AN AN ADDITIONAL ISOLATED PULSE SEVERE THUNDERSTORM WITH
DAMAGING WET MICROBURSTS. HOWEVER...DUE TO DIURNAL STABILIZATION THE
THREAT FOR SEVERE THUNDERSTORMS WILL CONTINUE TO WANE TONIGHT.
RESIDUAL CLOUD COVER PRODUCED BY EVENING CONVECTION WILL LIMIT
THE AMOUNT OF COOLING WHICH WILL TAKE PLACE TONIGHT...AND EXPECT
LOWS IN THE LOWER TO MID 70S AWAY FROM THE COAST...AND INTO THE
UPPER 70S/NEAR 80 AT THE COAST.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM FRIDAY/...
A COLD FRONT APPEARS TO STALL AND DISSIPATE JUST NORTHWEST OF THE
FORECAST AREA ON THURSDAY. A SOUTHERLY FLOW SHOULD PERSIST AT THE
SURFACE...BUT THE LOW TO MID LEVEL FLOW SHOULD BECOME NORTHWEST
ALLOWING SOME DRIER AIR TO ADVECT INTO THE AREA. WHILE THE DEEP
MOISTURE WILL NO LONGER BE IN PLACE...THERE WILL BE ENOUGH LOW
LEVEL MOISTURE TO WARRANT FORECASTING A SLIGHT CHANCE OF
SHOWERS/THUNDERSTORMS DURING THE AFTERNOON ACROSS MUCH OF THE
FORECAST AREA. ANY CONVECTION WILL COME TO AN END WITH THE LOSS OF
DAYTIME HEATING THURSDAY EVENING.
DEPENDING ON THE AMOUNT OF RESIDUAL CLOUDINESS IN PLACE...HIGHS
COULD REACH THE LOWER 90S AWAY FROM THE COAST ON THURSDAY. LOWS
THURSDAY NIGHT SHOULD FALL INTO THE UPPER 60S TO LOWER 70S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A MEAN UPPER LEVEL TROUGH WILL PERSIST FROM EASTERN CANADA SOUTHWARD
THROUGH THE MID ATLANTIC STATES...WHILE MEAN UPPER LEVEL RIDGING
PERSISTS ACROSS THE SOUTHWEST AND SOUTHERN PLAINS STATES.
MODELS CONTINUE TO DIFFER IN THE DETAILS DURING THE EXTENDED
PERIOD. GFS IS MORE AGGRESSIVE WITH SHORTWAVE ENERGY ROUNDING THE
BASE OF THE UPPER TROUGH...MAINTAINING DEEPER LEVEL MOISTURE
ACROSS THE FORECAST AREA. DESPITE MODEL DISAGREEMENT IN SOME OF
THE TIMING AND STRENGTH OF SYNOPTIC FEATURES....THE GENERAL SURFACE
PATTERN IS CONSISTENT BETWEEN THE MODELS. AN ATLANTIC RIDGE WILL
LINGER OVER THE MARINE ZONES...WITH A SURFACE TROUGH PERSISTING
INLAND. A GRADUAL INCREASE IN MOISTURE THROUGH EARLY NEXT
WEEK...IN ADDITION TO THE SERIES OF SHORTWAVES MOVING INTO THE
SOUTHEAST STATES...WILL MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON AND EARLY EVENING HOURS THROUGH
NEXT WEDNESDAY.
ANOTHER FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST LATE IN
THE WEEKEND THROUGH EARLY NEXT WEEK. CONSIDERING THE TIME OF YEAR
AND MODEL SOLUTIONS...THE FRONTAL BOUNDARY WILL LIKELY STALL JUST
NORTH OF THE REGION. LACKING ANY FRONTAL PASSAGE...SHOWER AND
THUNDERSTORM ACTIVITY IS EXPECTED TO REMAIN MOSTLY DIURNAL IN
NATURE. BEST CHANCE FOR CONVECTION WILL BE WITHIN SEABREEZE
FORCING AND INSTABILITY DURING THE AFTERNOON/EVENINGS...DIMINISHING
TO A SLIGHT CHANCE OR LESS OVERNIGHT.
AFTERNOON HEAT INDICES ARE EXPECTED TO TREND UPWARDS EACH DAY AS
LOW LEVEL MOISTURE INCREASES THROUGH THE PERIOD. HEAT INDICES IN SOME
LOCATIONS COULD EXCEED 105 DEGREES FROM SUNDAY THROUGH AT LEAST
TUESDAY...AS DEWPOINTS WILL REMAIN IN THE MID 70S DURING THE
AFTERNOON HOURS.
&&
.AVIATION /05Z THURSDAY THROUGH MONDAY/...
KCHS - THE MAIN LINE OF SHOWERS AND THUNDERSTORMS HAS PUSHED EAST
OF THE TERMINAL ALTHOUGH SOME ISOLATED ACTIVITY REMAINS ACROSS THE
MIDLANDS. THIS ACTIVITY IS EXPECTED TO DISSIPATE BEFORE REACHING
THE CHS AIRSPACE...BUT TRENDS WILL BE CAREFULLY WATCHED IN CASE AN
AMENDMENT IS NEEDED TO INCLUDE PCPN IN THE CHS TAF. MID-HIGH LEVEL
CLOUDINESS WILL GRADUALLY THIN OUT THIS MORNING BUT THERE SHOULD
BE ENOUGH PRECLUDE SIGNIFICANT FOG FORMATION THROUGH SUNRISE. THE
FOG POTENTIAL IS NOT NON-ZERO SINCE THE GROUNDS ARE WET FROM EARLIER
RAINS. WILL CARRY A TEMPO 5SM BR GROUP FROM 09-12Z TO COVER THIS
POSSIBILITY. OTHERWISE VFR CONDITIONS WILL PREVAIL FOR THE NEXT 24
HOURS.
KSAV - EXTENSIVE MID-HIGH LEVEL CLOUDINESS REMAINS IN PLACE THIS
MORNING. SATELLITE AND SURFACE OBSERVATIONS INDICATE A BROKEN DECK
AROUND 4000-5000 FT IS SLOWLY EXPANDING IN COVERAGE FROM VDI-TBR.
THIS AREA OF ENHANCED CLOUD COVER SHOULD REACH THE SAV TERMINAL
BY 09Z AND REMAIN IN PLACE THROUGH SUNRISE. THIS SHOULD PRECLUDE
SIGNIFICANT FOG DEVELOPMENT SO FOG WILL BE REMOVED FROM THE SAV
TAF WITH THE 06Z CYCLE. VFR CONDITIONS WILL PREVAIL FOR THE NEXT
24 HOURS.
EXTENDED AVIATION OUTLOOK...A CHANCE OF MVFR VSBYS EACH MORNING
DUE TO HIGH LOW LEVEL MOISTURE AND LIGHT WINDS...OTHERWISE VFR
CONDITIONS EXPECTED OUTSIDE OF MAINLY AFTERNOON/EVENING CONVECTION.
&&
.MARINE...
EAST OF AN INLAND SURFACE TROUGH...THE SURFACE PRESSURE GRADIENT
REMAINED TIGHT ACROSS THE COASTAL WATERS...SUPPORTING SMALL CRAFT
ADVISORY WINDS ACROSS SC COASTAL WATERS NORTH OF EDISTO
BEACH...OUTSIDE CHARLESTON HARBOR...AND ACROSS THE OUTER GA
WATERS. PER WEDNESDAY EVENING TRENDS...WILL EXTEND SCAS FOR AMZ350
AND AMZ374 UNTIL 6 AM. SYNOPTIC WINDS WILL BE ALTERED BY SHOWERS/
THUNDERSTORMS OVERNIGHT.
THE MARINE ZONES WILL REMAIN ON THE WESTERN PERIPHERY OF ATLANTIC
HIGH PRESSURE THROUGH THE EXTENDED PERIOD. WINDS WILL GENERALLY
MAINTAIN A SOUTHERLY COMPONENT INTO NEXT WEEK. SPEEDS WILL REMAIN
AT OR BELOW 15 KNOTS OUTSIDE OF ANY THUNDERSTORM ACTIVITY...WITH
SEAS AT OR BELOW 4 FEET.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR
AMZ350-374.
&&
$$
ST
000
FXUS62 KCAE 240514
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
114 AM EDT THU JUL 24 2008
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA OVERNIGHT. HIGH PRESSURE WILL
BUILD IN THURSDAY AND FRIDAY AHEAD OF ANOTHER COLD FRONT THAT WILL
REACH THE AREA ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SHORT WAVE CROSSING THE CENTRAL APPALACHIANS THIS EVENING.
WIDESPREAD CONVECTION NOW CROSSING THE EASTERN THIRD OF THE
MIDLANDS AND SHOULD BE EAST OF THE FORECAST AREA BETWEEN 11 PM AND
MIDNIGHT...THEN CLOUDS BREAKING UP. ISOLATED TO SCATTERED
CONVECTION POSSIBLE OVERNIGHT.
SURFACE COLD FRONT SHOULD BE EAST OF THE AREA BY 12Z. DRIER AIR
FILTERING IN FOR THURSDAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
FRONTAL SYSTEM WILL SLOWLY CROSS THE AREA DURING THE DAY ON
THURSDAY AND STALL OFF THE COAST THURSDAY EVENING AND INTO FRIDAY.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON FRIDAY. DRY
AIRMASS IN PLACE WILL KEEP POPS LOW THROUGH THE PERIOD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MODELS ARE IN AGREEMENT WITH ANOTHER FRONT APPROACHING SATURDAY
EVENING THAT WILL STALL ACROSS THE REGION...OR JUST OFF THE
COAST...THROUGH MID WEEK. HAVE DECIDED TO KEEP ISOLATED CHANCE
POPS THROUGH WEDNESDAY AS DIURNAL THUNDERSTORM ACTIVITY WILL BE POSSIBLE.
TEMPS FOR THE WEEKEND WILL BE SLIGHTLY ABOVE CLIMATOLOGY BUT WILL
BE BACK TO NORMAL MONDAY THROUGH WEDNESDAY.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
BATCH OF SHOWERS AND THUNDERSTORMS JUST WEST OF CAE
CURRENTLY...MOVING SE. WILL EXPECT TSRA ACTIVITY TO GRADUALLY
DISSIPATE OR MOVE OUT OF THE FORECAST AREA LATER TONIGHT.
DRIER AIR AND HIGH PRESSURE WILL FILTER IN THURSDAY...WITH NE
WINDS...AND LITTLE CLOUD COVER.
EXTENDED OUTLOOK...NO SIGNIFICANT IMPACTS TO AVIATION EXPECTED
THURSDAY THROUGH MONDAY.
$$
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCAE 240157
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
957 PM EDT WED JUL 23 2008
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA OVERNIGHT. HIGH PRESSURE WILL
BUILD IN THURSDAY AND FRIDAY AHEAD OF ANOTHER COLD FRONT THAT WILL
REACH THE AREA ON SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
SHORT WAVE CROSSING THE CENTRAL APPALACHIANS THIS EVENING.
WIDESPREAD CONVECTION NOW CROSSING THE EASTERN THIRD OF THE
MIDLANDS AND SHOULD BE EAST OF THE FORECAST AREA BETWEEN 11 PM AND
MIDNIGHT...THEN CLOUDS BREAKING UP. ISOLATED TO SCATTERED
CONVECTION POSSIBLE OVERNIGHT.
SURFACE COLD FRONT SHOULD BE EAST OF THE AREA BY 12Z. DRIER AIR
FILTERING IN FOR THURSDAY.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
FRONTAL SYSTEM WILL SLOWLY CROSS THE AREA DURING THE DAY ON
THURSDAY AND STALL OFF THE COAST THURSDAY EVENING AND INTO FRIDAY.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON FRIDAY. DRY
AIRMASS IN PLACE WILL KEEP POPS LOW THROUGH THE PERIOD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MODELS ARE IN AGREEMENT WITH ANOTHER FRONT APPROACHING SATURDAY
EVENING THAT WILL STALL ACROSS THE REGION...OR JUST OFF THE
COAST...THROUGH MID WEEK. HAVE DECIDED TO KEEP ISOLATED CHANCE
POPS THROUGH WEDNESDAY AS DIURNAL THUNDERSTORM ACTIVITY WILL BE POSSIBLE.
TEMPS FOR THE WEEKEND WILL BE SLIGHTLY ABOVE CLIMATOLOGY BUT WILL
BE BACK TO NORMAL MONDAY THROUGH WEDNESDAY.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
SCATTERED THUNDERSTORMS CURRENTLY PUSHING THROUGH THE AREA WILL
AFFECT CAE/CUB/OGB AND CAN EXPECT MVFR VISIBILITIES DROPPING
TEMPORARILY TO IFR THROUGH 01Z. CONDITIONS WILL LAST A BIT
LONGER...TIL AROUND 03Z AT OGB. AGS/DNL WILL NOT BE AFFECTED BY
THE STORMS.
A FRONTAL BOUNDARY WILL SLIP THROUGH OVERNIGHT BUT
WINDS WILL BE LIGHT ENOUGH THAT THE ONLY NOTICEABLE FEATURE WILL
BE DRIER AIR WORKING IN. WINDS WILL BECOME MORE NORTHEASTERLY ON
THURSDAY AS MIXING OCCURS. PLENTY OF DRY AIR IN THE LOW AND MID
LEVELS THURSDAY WILL PREVENT MUCH CLOUD COVER.
EXTENDED OUTLOOK...AT THIS TIME NO SIGNIFICANT IMPACTS TO AVIATION
EXPECTED FRIDAY EVENING THROUGH SUNDAY.
$$
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
NEAR TERM...10
000
FXUS62 KCHS 240149
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
949 PM EDT WED JUL 23 2008
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT WILL
APPROACH FROM THE NORTHWEST OVERNIGHT. THE WEAKENING FRONT WILL
STALL JUST NORTHWEST OF THE AREA THURSDAY BEFORE DISSIPATING.
ATLANTIC HIGH PRESSURE WILL REMAIN THROUGH THE MIDDLE OF NEXT
WEEK...WITH WEAK LOW PRESSURE ACROSS INLAND AREAS.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
MULTICELL CLUSTERS OF THUNDERSTORMS WILL CONTINUE TO ADVANCE E/SE
ACROSS THE FORECAST AREA OVERNIGHT...EXITING TO THE E/NE LATE.
WILL CONTINUE TO DIVIDE POPS INTO TWO PERIODS...WITH POPS
INITIALLY TAPERED FROM CHANCE/LIKELY ACROSS THE NORTHERN 2/3 OF
THE FORECAST AREA TO SLIGHT CHANCE S...THEN...WILL GRADUATE POPS
FROM SLIGHT CHANCE/CHANCE N/NE TO POPS BELOW 15 PERCENT W/SW
FOR THE BALANCE OF THE NIGHT.
DUE TO MESOSCALE BOUNDARY INTERACTIONS AND RESIDUAL INSTABILITY CANNOT
RULE OUT AN AN ADDITIONAL ISOLATED PULSE SEVERE THUNDERSTORM WITH
DAMAGING WET MICROBURSTS. HOWEVER...DUE TO DIURNAL STABILIZATION THE
THREAT FOR SEVERE THUNDERSTORMS WILL CONTINUE TO WANE TONIGHT.
RESIDUAL CLOUD COVER PRODUCED BY EVENING CONVECTION WILL LIMIT
THE AMOUNT OF COOLING WHICH WILL TAKE PLACE TONIGHT...AND EXPECT
LOWS IN THE LOWER TO MID 70S AWAY FROM THE COAST...AND INTO THE
UPPER 70S/NEAR 80 AT THE COAST.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
A COLD FRONT APPEARS TO STALL AND DISSIPATE JUST NORTHWEST OF THE
FORECAST AREA ON THURSDAY. A SOUTHERLY FLOW SHOULD PERSIST AT THE
SURFACE...BUT THE LOW TO MID LEVEL FLOW SHOULD BECOME NORTHWEST
ALLOWING SOME DRIER AIR TO ADVECT INTO THE AREA. WHILE THE DEEP
MOISTURE WILL NO LONGER BE IN PLACE...THERE WILL BE ENOUGH LOW
LEVEL MOISTURE TO WARRANT FORECASTING A SLIGHT CHANCE OF
SHOWERS/THUNDERSTORMS DURING THE AFTERNOON ACROSS MUCH OF THE
FORECAST AREA. ANY CONVECTION WILL COME TO AN END WITH THE LOSS OF
DAYTIME HEATING THURSDAY EVENING.
DEPENDING ON THE AMOUNT OF RESIDUAL CLOUDINESS IN PLACE...HIGHS
COULD REACH THE LOWER 90S AWAY FROM THE COAST ON THURSDAY. LOWS
THURSDAY NIGHT SHOULD FALL INTO THE UPPER 60S TO LOWER 70S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A MEAN UPPER LEVEL TROUGH WILL PERSIST FROM EASTERN CANADA SOUTHWARD
THROUGH THE MID ATLANTIC STATES...WHILE MEAN UPPER LEVEL RIDGING
PERSISTS ACROSS THE SOUTHWEST AND SOUTHERN PLAINS STATES.
MODELS CONTINUE TO DIFFER IN THE DETAILS DURING THE EXTENDED
PERIOD. GFS IS MORE AGGRESSIVE WITH SHORTWAVE ENERGY ROUNDING THE
BASE OF THE UPPER TROUGH...MAINTAINING DEEPER LEVEL MOISTURE
ACROSS THE FORECAST AREA. DESPITE MODEL DISAGREEMENT IN SOME OF
THE TIMING AND STRENGTH OF SYNOPTIC FEATURES....THE GENERAL SURFACE
PATTERN IS CONSISTENT BETWEEN THE MODELS. AN ATLANTIC RIDGE WILL
LINGER OVER THE MARINE ZONES...WITH A SURFACE TROUGH PERSISTING
INLAND. A GRADUAL INCREASE IN MOISTURE THROUGH EARLY NEXT
WEEK...IN ADDITION TO THE SERIES OF SHORTWAVES MOVING INTO THE
SOUTHEAST STATES...WILL MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON AND EARLY EVENING HOURS THROUGH
NEXT WEDNESDAY.
ANOTHER FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST LATE IN
THE WEEKEND THROUGH EARLY NEXT WEEK. CONSIDERING THE TIME OF YEAR
AND MODEL SOLUTIONS...THE FRONTAL BOUNDARY WILL LIKELY STALL JUST
NORTH OF THE REGION. LACKING ANY FRONTAL PASSAGE...SHOWER AND
THUNDERSTORM ACTIVITY IS EXPECTED TO REMAIN MOSTLY DIURNAL IN
NATURE. BEST CHANCE FOR CONVECTION WILL BE WITHIN SEABREEZE
FORCING AND INSTABILITY DURING THE AFTERNOON/EVENINGS...DIMINISHING
TO A SLIGHT CHANCE OR LESS OVERNIGHT.
AFTERNOON HEAT INDICES ARE EXPECTED TO TREND UPWARDS EACH DAY AS
LOW LEVEL MOISTURE INCREASES THROUGH THE PERIOD. HEAT INDICES IN SOME
LOCATIONS COULD EXCEED 105 DEGREES FROM SUNDAY THROUGH AT LEAST
TUESDAY...AS DEWPOINTS WILL REMAIN IN THE MID 70S DURING THE
AFTERNOON HOURS.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
THUNDERSTORMS COULD DIRECTLY IMPACT KCHS AND KSAV WITH BRIEF IFR
OR LOWER CONDITIONS AND GUSTY/SHIFTING WINDS BEFORE 06Z. EXPECT
TAF AMENDMENTS TO ADDRESS NEAR TERM CONVECTIVE TRENDS.
LATER TONIGHT INTO EARLY THURSDAY...LOW LEVEL MOISTURE MAY SUPPORT
BRIEF MVFR OR LOWER VISIBILITY AT EITHER TERMINAL. HOWEVER...MID/HIGH
LEVEL CLOUDS PRODUCED BY CONVECTION MAY LIMIT THIS POTENTIAL.
ISOLATED SHOWERS/THUNDERSTORMS MAY AGAIN DEVELOP ON THE SEA BREEZE
THURSDAY AFTERNOON. HOWEVER...THE SEA BREEZE MAY STRUGGLE TO PUSH
INLAND...AND LIMITED MENTION OF CBS TO KSAV AFTER 20Z.
EXTENDED AVIATION OUTLOOK...A CHANCE OF MVFR VSBYS EACH MORNING
DUE TO HIGH LOW LEVEL MOISTURE AND LIGHT WINDS...OTHERWISE VFR
CONDITIONS EXPECTED OUTSIDE OF MAINLY AFTERNOON/EVENING CONVECTION.
&&
.MARINE...
EAST OF AN INLAND SURFACE TROUGH...THE SURFACE PRESSURE GRADIENT
REMAINED TIGHT ACROSS THE COASTAL WATERS...SUPPORTING SMALL CRAFT
ADVISORY WINDS ACROSS SC COASTAL WATERS NORTH OF EDISTO
BEACH...OUTSIDE CHARLESTON HARBOR...AND ACROSS THE OUTER GA
WATERS. PER WEDNESDAY EVENING TRENDS...WILL EXTEND SCAS FOR AMZ350
AND AMZ374 UNTIL 6 AM. SYNOPTIC WINDS WILL BE ALTERED BY SHOWERS/
THUNDERSTORMS OVERNIGHT.
THE MARINE ZONES WILL REMAIN ON THE WESTERN PERIPHERY OF ATLANTIC
HIGH PRESSURE THROUGH THE EXTENDED PERIOD. WINDS WILL GENERALLY
MAINTAIN A SOUTHERLY COMPONENT INTO NEXT WEEK. SPEEDS WILL REMAIN
AT OR BELOW 15 KNOTS OUTSIDE OF ANY THUNDERSTORM ACTIVITY...WITH
SEAS AT OR BELOW 4 FEET.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR
AMZ350-374.
&&
$$
000
FXUS62 KCAE 240027
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
827 PM EDT WED JUL 23 2008
.SYNOPSIS...
FRONTAL SYSTEM APPROACHING FROM THE NORTHWEST WILL BRING INCREASED
CHANCES OF PRECIPITATION THIS EVENING. HIGH PRESSURE WILL BUILD
IN THURSDAY AND FRIDAY AHEAD OF ANOTHER COLD FRONT THAT WILL REACH
THE AREA ON SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
SURFACE TROUGH WILL PROVIDE FORCING FOR DEVELOPMENT FOR POSSIBLE SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING. ADDITIONALLY...SPC HAS
SC AND GA IN A SLIGHT RISK FOR SEVERE STORMS. MODERATE TO STRONG
INSTABILITY IN PLACE ACROSS THE REGION WITH LI VALUES AROUND
-6. PWS UPWARDS OF 1.75 INCHES WITH WEAK WIND SHEAR. SBCAPE AROUND
1500 J/KG ACROSS THE SOUTHERN AND CENTRAL MIDLANDS AND NEAR 2000
J/KG IN THE NORTH CENTRAL MIDLANDS. GREATEST THREAT POTENTIAL FROM
THUNDERSTORMS WILL BE HAIL AND LOCALLY HEAVY RAINFALL. HAVE KEPT
LIKELY POPS BUT INCREASED TO CATEGORICAL IN THE NORTH CENTRAL AREA
DUE TO BEST UPPER LEVEL SUPPORT FOR CONVECTION.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
FRONTAL SYSTEM WILL SLOWLY CROSS THE AREA DURING THE DAY ON
THURSDAY AND STALL OFF THE COAST THURSDAY EVENING AND INTO FRIDAY.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON FRIDAY. DRY
AIRMASS IN PLACE WILL KEEP POPS LOW THROUGH THE PERIOD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MODELS ARE IN AGREEMENT WITH ANOTHER FRONT APPROACHING SATURDAY
EVENING THAT WILL STALL ACROSS THE REGION...OR JUST OFF THE
COAST...THROUGH MID WEEK. HAVE DECIDED TO KEEP ISOLATED CHANCE
POPS THROUGH WEDNESDAY AS DIURNAL THUNDERSTORM ACTIVITY WILL BE POSSIBLE.
TEMPS FOR THE WEEKEND WILL BE SLIGHTLY ABOVE CLIMATOLOGY BUT WILL
BE BACK TO NORMAL MONDAY THROUGH WEDNESDAY.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
SCATTERED THUNDERSTORMS CURRENTLY PUSHING THROUGH THE AREA WILL
AFFECT CAE/CUB/OGB AND CAN EXPECT MVFR VISIBILITIES DROPPING
TEMPORARILY TO IFR THROUGH 01Z. CONDITIONS WILL LAST A BIT
LONGER...TIL AROUND 03Z AT OGB. AGS/DNL WILL NOT BE AFFECTED BY
THE STORMS.
A FRONTAL BOUNDARY WILL SLIP THROUGH OVERNIGHT BUT
WINDS WILL BE LIGHT ENOUGH THAT THE ONLY NOTICEABLE FEATURE WILL
BE DRIER AIR WORKING IN. WINDS WILL BECOME MORE NORTHEASTERLY ON
THURSDAY AS MIXING OCCURS. PLENTY OF DRY AIR IN THE LOW AND MID
LEVELS THURSDAY WILL PREVENT MUCH CLOUD COVER.
EXTENDED OUTLOOK...AT THIS TIME NO SIGNIFICANT IMPACTS TO AVIATION
EXPECTED FRIDAY EVENING THROUGH SUNDAY.
$$
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AVIATION...HC
000
FXUS62 KFFC 240004
AFDFFC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
804 PM EDT WED JUL 23 2008
.UPDATE...
MADE A QUICK UPDATE TO LOWER POPS ACROSS EXTREME NORTH. LATEST SURFACE
ANALYSIS SHOWS FRONT ENTERING NORTH GEORGIA...WITH DRIER AIR
KNOCKING ON THE DOORSTEP...NOTED BY DEWPOINTS IN THE 50S OVER
TENNESSEE. THUS...SHOULD NOT SEE ANY ADDITIONAL CONVECTIVE
DEVELOPMENT ACROSS THAT AREA THIS EVENING. LEFT CHANCE POPS
ELSEWHERE. NO CHANGES MADE TO TEMPERATURES.
&&
.PREV DISCUSSION... /ISSUED 530 PM EDT WED JUL 23 2008/
SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
FRONTAL BOUNDARY EVIDENT ON VISIBLE SATELLITE THIS AFTERNOON
ACROSS TENNESSEE. SHOWERS AND THUNDERSTORMS BEGINNING TO DEVELOP
ALONG FRONT...AS WELL AS ACROSS PORTIONS OF CENTRAL GEORGIA IN
ASSOCIATION WITH LEFTOVER OUTFLOW BOUNDARY FROM CONVECTION ON
TUESDAY. OVERALL...CONVECTION HAS BEEN SLOW TO DEVELOP TODAY
RELATIVE TO TUESDAY...DUE TO CLOUD COVER KEEPING THE LOWER LEVELS
OF THE ATMOSPHERE RELATIVELY COOL AND STABLE. STILL EXPECT CHANCES
FOR SHOWERS AND THUNDERSTORMS TO INCREASE ACROSS ALL OF NORTH AND
CENTRAL GEORGIA LATE THIS AFTERNOON INTO THE EVENING AS FRONT
APPROACHES. HIGHEST POPS WILL BE ACROSS CENTRAL GEORGIA WHERE
BETTER INSTABILITY AND SURFACE TROUGH ARE IN PLACE. THREAT FOR
SEVERE THUNDERSTORMS APPEARS LESS THIS EVENING RELATIVE TO TUESDAY
AS FREEZING LEVEL HAS RISEN SLIGHTLY AND ATMOSPHERE IS MORE
SATURATED...WITH LESS POTENTIAL FOR DOWNBURSTS.
NAM/GFS HAVE DIFFERENT SCENARIOS FOR WHAT THE FRONTAL BOUNDARY
WILL DO ONCE IT ARRIVES IN GEORGIA. NAM PUSHES THE FRONT THROUGH
THE STATE ALL THE WAY THROUGH GEORGIA AND INTO FLORIDA...WHILE
THE GFS STALLS THE BOUNDARY ACROSS CENTRAL GEORGIA...CONTINUING
CHANCES FOR SHOWERS AND THUNDERSTORMS FOR THURSDAY AND EVEN
POSSIBLY FRIDAY. LEANED HEAVILY TOWARDS THE GFS SOLUTION AS
CHANCES OF A FRONT MAKING IT ALL THE WAY TO FLORIDA IN LATE JULY
ARE LOW. ON FRIDAY THE GFS DEVELOPS A SIGNIFICANT AREA OF
CONVECTION...POSSIBLY AN MCS...ACROSS THE TENNESSEE RIVER VALLEY
AND RAPIDLY PUSHES THE SYSTEM INTO ALABAMA AND WEST GEORGIA FRIDAY
EVENING. NAM SHOWS A SIMILAR SYSTEM...HOWEVER MUCH FARTHER
NORTH...AND WITH A MORE EASTERLY TRAJECTORY ACROSS THE OHIO RIVER
VALLEY. LEANED TOWARDS NAM SOLUTION IN THIS CASE AS THAT IS A MORE
FAVORED AREA FOR SUCH SYSTEMS. HOWEVER DID SHOW SOME INCREASE IN
POPS ACROSS WEST GEORGIA FRIDAY AFTERNOON AS A COMPROMISE BETWEEN
THE TWO SOLUTIONS. GENERALLY STAYED CLOSE TO MOS ON TEMPERATURES.
SOME DRIER AIR MAY WORK INTO NORTH GEORGIA TONIGHT WITH COOLER
TEMPERATURES THAN HAVE BEEN SEEN THERE IN SEVERAL DAYS. TEMPERATURES
SHOULD QUICKLY WARM TO THE 90S ON THURSDAY...PARTICULARLY ACROSS
NORTH GEORGIA WHERE H8 TEMPERATURES APPROACH +20 DEGREES C.
LONG TERM /SATURDAY THROUGH WEDNESDAY/...
NO SIGNIFICANT CHANGE OF PATTERN APPEARS LIKELY THROUGH THE
EXTENDED PERIOD. UPPER RIDGE REMAINS ANCHORED ACROSS THE SOUTH
CENTRAL PART OF THE UNITED STATES...EVENTUALLY GETTING PUSHED
FARTHER WEST...ACROSS THE DESERT SOUTHWEST EARLY NEXT WEEK. THIS
SCENARIO WILL KEEP GEORGIA IN NORTHWEST FLOW THROUGH THE EXTENDED
PERIOD WITH CHANCES FOR PRECIP EVERY DAY AS DISTURBANCES RIDE THE
NORTHWEST FLOW ALONG THE PERIPHERY OF THE UPPER-RIDGE. THIS
PATTERN SHOULD KEEP TEMPERATURES IN THE EXTENDED NEAR SEASONAL
AVERAGES.
FIRE WEATHER...
FRONTAL BOUNDARY APPROACHING NORTH AND CENTRAL GEORGIA
TONIGHT...INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS. FRONT
FRONT SHOULD STALL SOMEWHERE ACROSS CENTRAL GEORGIA ON
THURSDAY...RESULTING IN CONTINUED CHANCES FOR SHOWERS AND
THUNDERSTORMS ACROSS CENTRAL GEORGIA...WITH DRIER CONDITIONS
ACROSS THE NORTHERN PORTION OF THE STATE.
AVIATION...
THUNDERSTORMS SLOW TO DEVELOP SO FAR THIS AFTERNOON. COVERAGE
ISOLATED AT BEST. HOWEVER...WITH FRONT/TROUGH IN THE AREA...EXPECT
TO SEE AT LEAST SCATTERED ACTIVITY ACROSS THE AREA THROUGH THE
EVENING. AT THIS POINT...LEANING TOWARD GOING WITH VCTS ALL TAF
SITES UNTIL AROUND 02Z/04Z. HOWEVER...DO HAVE SOME CONCERN THAT
COULD SEE ISOLATED SHOWERS CONTINUE PASS MIDNIGHT WITH FRONT/TROUGH
IN THE AREA. OUTSIDE OF T-STORM AREAS...VFR CONDITIONS SHOULD
PREVAIL OVERNIGHT AND INTO THURSDAY. HAZE/PATCHY FOG MAY RESTRICT
VSBYS 3 TO 5 MILES LATE TONIGHT/EARLY THURSDAY. ISOLATED TO
SCATTERED T-STORMS AGAIN THURSDAY AFTERNOON...ESPECIALLY
ACROSS CENTRAL GEORGIA. PLAN TO GO WITH VCTS FOR NOW. WINDS A HARD
CALL WITH BOUNDARY(S) IN THE AREA. WILL GENERALLY VARY FROM WEST TO
NORTHWEST OVERNIGHT...THEN NORTHWEST TO NORTH THURSDAY.
049
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 67 94 67 92 68 / 30 10 5 20 10
ATLANTA 68 90 71 90 70 / 30 10 5 20 20
BLAIRSVILLE 62 88 61 88 64 / 10 10 10 20 20
CARTERSVILLE 63 91 62 89 67 / 20 10 10 20 20
COLUMBUS 71 91 73 92 73 / 40 30 20 30 20
GAINESVILLE 66 89 66 88 69 / 30 10 5 20 20
MACON 70 91 69 94 71 / 40 30 20 20 10
ROME 65 93 67 92 69 / 10 10 10 30 20
PEACHTREE CITY 64 91 65 90 67 / 30 10 5 20 20
VIDALIA 71 92 69 92 70 / 40 30 20 20 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MSR
000
FXUS62 KCHS 232333
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
733 PM EDT WED JUL 23 2008
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT WILL
APPROACH FROM THE NORTHWEST TONIGHT. THE WEAKENING FRONT WILL
STALL JUST NORTHWEST OF THE AREA THURSDAY BEFORE DISSIPATING.
ATLANTIC HIGH PRESSURE WILL REMAIN THROUGH THE MIDDLE OF NEXT
WEEK...WITH WEAK LOW PRESSURE ACROSS INLAND AREAS.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
EARLY WEDNESDAY EVENING...THUNDERSTORMS WERE FIRING ALONG VARIOUS
BOUNDARIES ACROSS S/W COUNTIES OF THE FORECAST AREA...WHILE
ONGOING MULTICELL CLUSTERS WERE ADVANCING FROM THE MIDLANDS INTO
INLAND COUNTIES OF THE FORECAST AREA. ADJUSTED EVENING POPS TO
LIKELY INLAND THIS EVENING...TAPERED TO SLIGHT CHANCE ACROSS FAR
N/E COUNTIES...THEN...TRANSITIONED TO SLIGHT CHANCE TO CHANCE POPS
OVERNIGHT AS RESIDUAL SHOWERS/THUNDERSTORMS PUSH TOWARD THE
COAST/COASTAL WATERS. MAY YET NEED TO RAISE POPS
OVERNIGHT...ESPECIALLY ACROSS N/E COUNTIES...IF ONGOING
MULTICELLULAR CONVECTION PERSISTS.
THE HIGHEST POTENTIAL FOR ISOLATED DAMAGING WET MICROBURSTS AND
LARGE HAIL WILL EXIST UNTIL AROUND MIDNIGHT...THEN...DIURNAL
STABILIZATION SHOULD LIMIT THE POTENTIAL FOR SEVERE THUNDERSTORMS
OVERNIGHT.
RESIDUAL CLOUD COVER PRODUCED BY EVENING CONVECTION WILL LIMIT
THE AMOUNT OF COOLING WHICH WILL TAKE PLACE TONIGHT...AND EXPECT
LOWS IN THE LOWER TO MID 70S AWAY FROM THE COAST...AND INTO THE
UPPER 70S/NEAR 80 AT THE COAST.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
A COLD FRONT APPEARS TO STALL AND DISSIPATE JUST NORTHWEST OF THE
FORECAST AREA ON THURSDAY. A SOUTHERLY FLOW SHOULD PERSIST AT THE
SURFACE...BUT THE LOW TO MID LEVEL FLOW SHOULD BECOME NORTHWEST
ALLOWING SOME DRIER AIR TO ADVECT INTO THE AREA. WHILE THE DEEP
MOISTURE WILL NO LONGER BE IN PLACE...THERE WILL BE ENOUGH LOW
LEVEL MOISTURE TO WARRANT FORECASTING A SLIGHT CHANCE OF
SHOWERS/THUNDERSTORMS DURING THE AFTERNOON ACROSS MUCH OF THE
FORECAST AREA. ANY CONVECTION WILL COME TO AN END WITH THE LOSS OF
DAYTIME HEATING THURSDAY EVENING.
DEPENDING ON THE AMOUNT OF RESIDUAL CLOUDINESS IN PLACE...HIGHS
COULD REACH THE LOWER 90S AWAY FROM THE COAST ON THURSDAY. LOWS
THURSDAY NIGHT SHOULD FALL INTO THE UPPER 60S TO LOWER 70S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A MEAN UPPER LEVEL TROUGH WILL PERSIST FROM EASTERN CANADA SOUTHWARD
THROUGH THE MID ATLANTIC STATES...WHILE MEAN UPPER LEVEL RIDGING
PERSISTS ACROSS THE SOUTHWEST AND SOUTHERN PLAINS STATES.
MODELS CONTINUE TO DIFFER IN THE DETAILS DURING THE EXTENDED
PERIOD. GFS IS MORE AGGRESSIVE WITH SHORTWAVE ENERGY ROUNDING THE
BASE OF THE UPPER TROUGH...MAINTAINING DEEPER LEVEL MOISTURE
ACROSS THE FORECAST AREA. DESPITE MODEL DISAGREEMENT IN SOME OF
THE TIMING AND STRENGTH OF SYNOPTIC FEATURES....THE GENERAL SURFACE
PATTERN IS CONSISTENT BETWEEN THE MODELS. AN ATLANTIC RIDGE WILL
LINGER OVER THE MARINE ZONES...WITH A SURFACE TROUGH PERSISTING
INLAND. A GRADUAL INCREASE IN MOISTURE THROUGH EARLY NEXT
WEEK...IN ADDITION TO THE SERIES OF SHORTWAVES MOVING INTO THE
SOUTHEAST STATES...WILL MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON AND EARLY EVENING HOURS THROUGH
NEXT WEDNESDAY.
ANOTHER FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST LATE IN
THE WEEKEND THROUGH EARLY NEXT WEEK. CONSIDERING THE TIME OF YEAR
AND MODEL SOLUTIONS...THE FRONTAL BOUNDARY WILL LIKELY STALL JUST
NORTH OF THE REGION. LACKING ANY FRONTAL PASSAGE...SHOWER AND
THUNDERSTORM ACTIVITY IS EXPECTED TO REMAIN MOSTLY DIURNAL IN
NATURE. BEST CHANCE FOR CONVECTION WILL BE WITHIN SEABREEZE
FORCING AND INSTABILITY DURING THE AFTERNOON/EVENINGS...DIMINISHING
TO A SLIGHT CHANCE OR LESS OVERNIGHT.
AFTERNOON HEAT INDICES ARE EXPECTED TO TREND UPWARDS EACH DAY AS
LOW LEVEL MOISTURE INCREASES THROUGH THE PERIOD. HEAT INDICES IN SOME
LOCATIONS COULD EXCEED 105 DEGREES FROM SUNDAY THROUGH AT LEAST
TUESDAY...AS DEWPOINTS WILL REMAIN IN THE MID 70S DURING THE
AFTERNOON HOURS.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
MOST FORECAST ATTENTION WILL FOCUS ON CONVECTIVE TRENDS TONIGHT.
INCLUDED CBS AT BOTH TERMINALS THIS EVENING...WITH OCCASIONAL
SHOWERS AT KSAV...BUT EITHER TERMINAL COULD BE DIRECTLY IMPACTED
BY STRONGER THUNDERSTORMS WITH BRIEF IFR OR LOWER CONDITIONS
AND GUSTY/SHIFTING WINDS...ESPECIALLY AFTER 01-02Z. EXPECT
AMENDMENTS TO ADDRESS NEAR TERM CONVECTIVE TRENDS.
LATER TONIGHT INTO EARLY THURSDAY...LOW LEVEL MOISTURE MAY SUPPORT
BRIEF MVFR OR LOWER VISIBILITY AT EITHER TERMINAL. HOWEVER...MID/HIGH
LEVEL CLOUDS PRODUCED BY CONVECTION MAY LIMIT THIS POTENTIAL.
ISOLATED SHOWERS/THUNDERSTORMS MAY AGAIN DEVELOP ON THE SEA BREEZE
THURSDAY AFTERNOON. HOWEVER...THE SEA BREEZE MAY STRUGGLE TO PUSH
INLAND...AND LIMITED MENTION OF CBS TO KSAV AFTER 20Z.
EXTENDED AVIATION OUTLOOK...A CHANCE OF MVFR VSBYS EACH MORNING
DUE TO HIGH LOW LEVEL MOISTURE AND LIGHT WINDS...OTHERWISE VFR
CONDITIONS EXPECTED OUTSIDE OF MAINLY AFTERNOON/EVENING CONVECTION.
&&
.MARINE...
AS SURFACE PRESSURE FELL INLAND...THE SURFACE PRESSURE GRADIENT HAD
TIGHTENED ACROSS COASTAL WATERS. PER RECENT OBSERVATION TRENDS...
ISSUED A SMALL CRAFT ADVISORY UNTIL MIDNIGHT FOR SC COASTAL
WATERS NORTH OF EDISTO BEACH...INCLUDING CHARLESTON HARBOR...AND
FOR THE OUTER GA WATERS. WILL CONTINUE TO ASSESS TRENDS THIS
EVENING...AND MAY YET NEED TO EXTEND THE SCAS INTO THE OVERNIGHT
HOURS. ALSO...SYNOPTIC WINDS WILL BE ALTERED BY SHOWERS/
THUNDERSTORMS TONIGHT.
THE MARINE ZONES WILL REMAIN ON THE WESTERN PERIPHERY OF ATLANTIC
HIGH PRESSURE THROUGH THE EXTENDED PERIOD. WINDS WILL GENERALLY
MAINTAIN A SOUTHERLY COMPONENT INTO NEXT WEEK. SPEEDS WILL REMAIN
AT OR BELOW 15 KNOTS OUTSIDE OF ANY THUNDERSTORM ACTIVITY...WITH
SEAS AT OR BELOW 4 FEET.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR AMZ330-350-
374.
&&
$$
000
FXUS62 KCHS 232211
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
611 PM EDT WED JUL 23 2008
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT WILL
APPROACH FROM THE NORTHWEST TONIGHT. THE WEAKENING FRONT WILL
STALL JUST NORTHWEST OF THE AREA THURSDAY BEFORE DISSIPATING.
ATLANTIC HIGH PRESSURE WILL REMAIN THROUGH THE MIDDLE OF NEXT
WEEK...WITH WEAK LOW PRESSURE ACROSS INLAND AREAS.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
THE FORECAST AREA HAS GENERALLY REMAINED FREE OF ANY CONVECTION
INTO WEDNESDAY EVENING...WHILE SHOWERS AND THUNDERSTORMS HAVE BECOME
WIDESPREAD ELSEWHERE IN THE CAROLINAS AND GEORGIA. THE CONVECTION
ACROSS SOUTHERN GEORGIA AND NORTHERN FLORIDA HAS LIKELY ROBBED
SOME OF THE AVAILABLE MOISTURE TODAY...WHILE CLOUD COVER HAS
HELPED TO STABILIZE THE ATMOSPHERE SOME OVER THE FORECAST AREA.
WATER VAPOR IMAGERY DEPICTS A RATHER HIGHLY AMPLIFIED UPPER LEVEL
TROUGH OVER THE OHIO VALLEY...WITH A POTENT SHORT WAVE ROTATING
AROUND THE BASE. THE SOUTHERN END OF THIS SHORT WAVE WILL MOVE
FROM THE SOUTHERN APPALACHIANS LATE THIS AFTERNOON TO THE COASTAL
PLAIN OF THE CAROLINAS TONIGHT.
PRECIPITATION WILL BE DIFFICULT TO FORECAST TONIGHT GIVEN COMPLEX
MESOSCALE AND SYNOPTIC FEATURES INFLUENCING CONVECTIVE FORMATION
AND MOVEMENT. HOWEVER...THERE SHOULD BE A GOOD CHANCE OF
CONVECTION THIS EVENING...FIRST OVER SOUTHEAST GA BASED ON CURRENT
RADAR TRENDS...THEN OVER SOUTHEAST SC AS THE SHORTWAVE AND
ASSOCIATED CONVECTION DROP SOUTHEAST TOWARD THE AREA. WHILE IT IS
POSSIBLE THAT THE CONVECTION AHEAD OF THE SHORT WAVE COULD
ORGANIZE INTO A MESOSCALE CONVECTIVE SYSTEM...THE TIMING COULD BE
TOO LATE TO TAKE ADVANTAGE OF WHATEVER MEAGER INSTABILITY IS IN
PLACE. THE FORECAST AREA REMAINS IN A SLIGHT RISK FOR SEVERE
WEATHER...BUT THINK ANY SEVERE THREAT WILL BE ISOLATED...WITH
DAMAGING WINDS AND MARGINALLY SEVERE HAIL POSSIBLE. FREQUENT
LIGHTNING AND LOCALLY HEAVY RAINFALL WILL ALSO ACCOMPANY ANY
THUNDERSTORMS.
CHANCES OF RAINFALL WILL COME TO AN END ACROSS INTERIOR SOUTHEAST
GA LATE TONIGHT AS THE SHORT WAVE MOVES TO THE COAST...HOWEVER
WILL MAINTAIN SLIGHT CHANCE OR LOW CHANCE POPS ELSEWHERE TO
ACCOUNT FOR ANY LINGERING PRECIPITATION.
A GOOD DEAL OF CLOUD COVER WILL LIMIT THE AMOUNT OF COOLING WHICH
WILL TAKE PLACE TONIGHT...AND EXPECT LOWS IN THE LOWER TO MID 70S
AWAY FROM THE COAST.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
A COLD FRONT APPEARS TO STALL AND DISSIPATE JUST NORTHWEST OF THE
FORECAST AREA ON THURSDAY. A SOUTHERLY FLOW SHOULD PERSIST AT THE
SURFACE...BUT THE LOW TO MID LEVEL FLOW SHOULD BECOME NORTHWEST
ALLOWING SOME DRIER AIR TO ADVECT INTO THE AREA. WHILE THE DEEP
MOISTURE WILL NO LONGER BE IN PLACE...THERE WILL BE ENOUGH LOW
LEVEL MOISTURE TO WARRANT FORECASTING A SLIGHT CHANCE OF
SHOWERS/THUNDERSTORMS DURING THE AFTERNOON ACROSS MUCH OF THE
FORECAST AREA. ANY CONVECTION WILL COME TO AN END WITH THE LOSS OF
DAYTIME HEATING THURSDAY EVENING.
DEPENDING ON THE AMOUNT OF RESIDUAL CLOUDINESS IN PLACE...HIGHS
COULD REACH THE LOWER 90S AWAY FROM THE COAST ON THURSDAY. LOWS
THURSDAY NIGHT SHOULD FALL INTO THE UPPER 60S TO LOWER 70S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A MEAN UPPER LEVEL TROUGH WILL PERSIST FROM EASTERN CANADA SOUTHWARD
THROUGH THE MID ATLANTIC STATES...WHILE MEAN UPPER LEVEL RIDGING
PERSISTS ACROSS THE SOUTHWEST AND SOUTHERN PLAINS STATES.
MODELS CONTINUE TO DIFFER IN THE DETAILS DURING THE EXTENDED
PERIOD. GFS IS MORE AGGRESSIVE WITH SHORTWAVE ENERGY ROUNDING THE
BASE OF THE UPPER TROUGH...MAINTAINING DEEPER LEVEL MOISTURE
ACROSS THE FORECAST AREA. DESPITE MODEL DISAGREEMENT IN SOME OF
THE TIMING AND STRENGTH OF SYNOPTIC FEATURES....THE GENERAL SURFACE
PATTERN IS CONSISTENT BETWEEN THE MODELS. AN ATLANTIC RIDGE WILL
LINGER OVER THE MARINE ZONES...WITH A SURFACE TROUGH PERSISTING
INLAND. A GRADUAL INCREASE IN MOISTURE THROUGH EARLY NEXT
WEEK...IN ADDITION TO THE SERIES OF SHORTWAVES MOVING INTO THE
SOUTHEAST STATES...WILL MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON AND EARLY EVENING HOURS THROUGH
NEXT WEDNESDAY.
ANOTHER FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST LATE IN
THE WEEKEND THROUGH EARLY NEXT WEEK. CONSIDERING THE TIME OF YEAR
AND MODEL SOLUTIONS...THE FRONTAL BOUNDARY WILL LIKELY STALL JUST
NORTH OF THE REGION. LACKING ANY FRONTAL PASSAGE...SHOWER AND
THUNDERSTORM ACTIVITY IS EXPECTED TO REMAIN MOSTLY DIURNAL IN
NATURE. BEST CHANCE FOR CONVECTION WILL BE WITHIN SEABREEZE
FORCING AND INSTABILITY DURING THE AFTERNOON/EVENINGS...DIMINISHING
TO A SLIGHT CHANCE OR LESS OVERNIGHT.
AFTERNOON HEAT INDICES ARE EXPECTED TO TREND UPWARDS EACH DAY AS
LOW LEVEL MOISTURE INCREASES THROUGH THE PERIOD. HEAT INDICES IN SOME
LOCATIONS COULD EXCEED 105 DEGREES FROM SUNDAY THROUGH AT LEAST
TUESDAY...AS DEWPOINTS WILL REMAIN IN THE MID 70S DURING THE
AFTERNOON HOURS.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
MAIN CONCERN WILL BE POTENTIAL FOR THUNDERSTORM DEVELOPMENT INTO
THIS EVENING. WITH LOW CONFIDENCE IN TIMING AND COVERAGE...HAVE
JUST A MENTION OF CB UNTIL RADAR TRENDS BECOME MORE EVIDENT. WILL
CONTINUE TO MONITOR THE SITUATION.
FOR TONIGHT...FOG DEVELOPMENT SHOULD BE MINIMAL AS CLOUD COVER
WILL BE IN PLACE AND SURFACE WINDS WILL BE UP CLOSE TO 10 KNOTS
BEFORE SUBSIDING JUST BEFORE DAYBREAK. IF EITHER TERMINAL
EXPERIENCES ANY SHOWER ACTIVITY THIS EVENING...FOG MAY DEVELOP AND
REDUCE VISIBILITIES TO MVFR LEVELS DUE TO THE RESIDUAL MOISTURE.
EXTENDED AVIATION OUTLOOK...A CHANCE OF MVFR VSBYS EACH MORNING
DUE TO HIGH LOW LEVEL MOISTURE AND LIGHT WINDS...OTHERWISE VFR
CONDITIONS EXPECTED OUTSIDE OF MAINLY AFTERNOON/EVENING CONVECTION.
&&
.MARINE...
AS SURFACE PRESSURE FELL INLAND...THE SURFACE PRESSURE GRADIENT HAD
TIGHTENED ACROSS COASTAL WATERS. PER RECENT OBSERVATION TRENDS...
ISSUED A SMALL CRAFT ADVISORY UNTIL MIDNIGHT FOR SC COASTAL
WATERS NORTH OF EDISTO BEACH...INCLUDING CHARLESTON HARBOR...AND
FOR THE OUTER GA WATERS. WILL CONTINUE TO ASSESS TRENDS THIS
EVENING...AND MAY YET NEED TO EXTEND THE SCAS INTO THE OVERNIGHT
HOURS.
THE MARINE ZONES WILL REMAIN ON THE WESTERN PERIPHERY OF ATLANTIC
HIGH PRESSURE THROUGH THE EXTENDED PERIOD. WINDS WILL GENERALLY
MAINTAIN A SOUTHERLY COMPONENT INTO NEXT WEEK. SPEEDS WILL REMAIN
AT OR BELOW 15 KNOTS OUTSIDE OF ANY THUNDERSTORM ACTIVITY...WITH
SEAS AT OR BELOW 4 FEET.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR AMZ330-350-
374.
&&
$$
000
FXUS62 KFFC 232130 AAA
AFDFFC
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
530 PM EDT WED JUL 23 2008
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
FRONTAL BOUNDARY EVIDENT ON VISIBLE SATELLITE THIS AFTERNOON
ACROSS TENNESSEE. SHOWERS AND THUNDERSTORMS BEGINNING TO DEVELOP
ALONG FRONT...AS WELL AS ACROSS PORTIONS OF CENTRAL GEORGIA IN
ASSOCIATION WITH LEFTOVER OUTFLOW BOUNDARY FROM CONVECTION ON
TUESDAY. OVERALL...CONVECTION HAS BEEN SLOW TO DEVELOP TODAY
RELATIVE TO TUESDAY...DUE TO CLOUD COVER KEEPING THE LOWER LEVELS
OF THE ATMOSPHERE RELATIVELY COOL AND STABLE. STILL EXPECT CHANCES
FOR SHOWERS AND THUNDERSTORMS TO INCREASE ACROSS ALL OF NORTH AND
CENTRAL GEORGIA LATE THIS AFTERNOON INTO THE EVENING AS FRONT
APPROACHES. HIGHEST POPS WILL BE ACROSS CENTRAL GEORGIA WHERE
BETTER INSTABILITY AND SURFACE TROUGH ARE IN PLACE. THREAT FOR
SEVERE THUNDERSTORMS APPEARS LESS THIS EVENING RELATIVE TO TUESDAY
AS FREEZING LEVEL HAS RISEN SLIGHTLY AND ATMOSPHERE IS MORE
SATURATED...WITH LESS POTENTIAL FOR DOWNBURSTS.
NAM/GFS HAVE DIFFERENT SCENARIOS FOR WHAT THE FRONTAL BOUNDARY
WILL DO ONCE IT ARRIVES IN GEORGIA. NAM PUSHES THE FRONT THROUGH
THE STATE ALL THE WAY THROUGH GEORGIA AND INTO FLORIDA...WHILE
THE GFS STALLS THE BOUNDARY ACROSS CENTRAL GEORGIA...CONTINUING
CHANCES FOR SHOWERS AND THUNDERSTORMS FOR THURSDAY AND EVEN
POSSIBLY FRIDAY. LEANED HEAVILY TOWARDS THE GFS SOLUTION AS
CHANCES OF A FRONT MAKING IT ALL THE WAY TO FLORIDA IN LATE JULY
ARE LOW. ON FRIDAY THE GFS DEVELOPS A SIGNIFICANT AREA OF
CONVECTION...POSSIBLY AN MCS...ACROSS THE TENNESSEE RIVER VALLEY
AND RAPIDLY PUSHES THE SYSTEM INTO ALABAMA AND WEST GEORGIA FRIDAY
EVENING. NAM SHOWS A SIMILAR SYSTEM...HOWEVER MUCH FARTHER
NORTH...AND WITH A MORE EASTERLY TRAJECTORY ACROSS THE OHIO RIVER
VALLEY. LEANED TOWARDS NAM SOLUTION IN THIS CASE AS THAT IS A MORE
FAVORED AREA FOR SUCH SYSTEMS. HOWEVER DID SHOW SOME INCREASE IN
POPS ACROSS WEST GEORGIA FRIDAY AFTERNOON AS A COMPROMISE BETWEEN
THE TWO SOLUTIONS. GENERALLY STAYED CLOSE TO MOS ON TEMPERATURES.
SOME DRIER AIR MAY WORK INTO NORTH GEORGIA TONIGHT WITH COOLER
TEMPERATURES THAN HAVE BEEN SEEN THERE IN SEVERAL DAYS. TEMPERATURES
SHOULD QUICKLY WARM TO THE 90S ON THURSDAY...PARTICULARLY ACROSS
NORTH GEORGIA WHERE H8 TEMPERATURES APPROACH +20 DEGREES C.
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
NO SIGNIFICANT CHANGE OF PATTERN APPEARS LIKELY THROUGH THE
EXTENDED PERIOD. UPPER RIDGE REMAINS ANCHORED ACROSS THE SOUTH
CENTRAL PART OF THE UNITED STATES...EVENTUALLY GETTING PUSHED
FARTHER WEST...ACROSS THE DESERT SOUTHWEST EARLY NEXT WEEK. THIS
SCENARIO WILL KEEP GEORGIA IN NORTHWEST FLOW THROUGH THE EXTENDED
PERIOD WITH CHANCES FOR PRECIP EVERY DAY AS DISTURBANCES RIDE THE
NORTHWEST FLOW ALONG THE PERIPHERY OF THE UPPER-RIDGE. THIS
PATTERN SHOULD KEEP TEMPERATURES IN THE EXTENDED NEAR SEASONAL
AVERAGES.
&&
.FIRE WEATHER...
FRONTAL BOUNDARY APPROACHING NORTH AND CENTRAL GEORGIA
TONIGHT...INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS. FRONT
FRONT SHOULD STALL SOMEWHERE ACROSS CENTRAL GEORGIA ON
THURSDAY...RESULTING IN CONTINUED CHANCES FOR SHOWERS AND
THUNDERSTORMS ACROSS CENTRAL GEORGIA...WITH DRIER CONDITIONS
ACROSS THE NORTHERN PORTION OF THE STATE.
&&
.AVIATION...
THUNDERSTORMS SLOW TO DEVELOP SO FAR THIS AFTERNOON. COVERAGE
ISOLATED AT BEST. HOWEVER...WITH FRONT/TROUGH IN THE AREA...EXPECT
TO SEE AT LEAST SCATTERED ACTIVITY ACROSS THE AREA THROUGH THE
EVENING. AT THIS POINT...LEANING TOWARD GOING WITH VCTS ALL TAF
SITES UNTIL AROUND 02Z/04Z. HOWEVER...DO HAVE SOME CONCERN THAT
COULD SEE ISOLATED SHOWERS CONTINUE PASS MIDNIGHT WITH FRONT/TROUGH
IN THE AREA. OUTSIDE OF T-STORM AREAS...VFR CONDITIONS SHOULD
PREVAIL OVERNIGHT AND INTO THURSDAY. HAZE/PATCHY FOG MAY RESTRICT
VSBYS 3 TO 5 MILES LATE TONIGHT/EARLY THURSDAY. ISOLATED TO
SCATTERED T-STORMS AGAIN THURSDAY AFTERNOON...ESPECIALLY
ACROSS CENTRAL GEORGIA. PLAN TO GO WITH VCTS FOR NOW. WINDS A HARD
CALL WITH BOUNDARY(S) IN THE AREA. WILL GENERALLY VARY FROM WEST TO
NORTHWEST OVERNIGHT...THEN NORTHWEST TO NORTH THURSDAY.
049
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 67 94 67 92 68 / 30 10 5 20 10
ATLANTA 68 90 71 90 70 / 20 10 5 20 20
BLAIRSVILLE 62 88 61 88 64 / 20 10 10 20 20
CARTERSVILLE 63 91 62 89 67 / 20 10 10 20 20
COLUMBUS 71 91 73 92 73 / 40 30 20 30 20
GAINESVILLE 66 89 66 88 69 / 30 10 5 20 20
MACON 70 91 69 94 71 / 40 30 20 20 10
ROME 65 93 67 92 69 / 20 10 10 30 20
PEACHTREE CITY 64 91 65 90 67 / 20 10 5 20 20
VIDALIA 71 92 69 92 70 / 50 30 20 20 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MSR
000
FXUS62 KCHS 232008
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
408 PM EDT WED JUL 23 2008
.SYNOPSIS...
AN UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT WILL
APPROACH FROM THE NORTHWEST TONIGHT. THE WEAKENING FRONT WILL
STALL JUST NORTHWEST OF THE AREA THURSDAY BEFORE DISSIPATING.
ATLANTIC HIGH PRESSURE WILL REMAIN THROUGH THE MIDDLE OF NEXT
WEEK...WITH WEAK LOW PRESSURE ACROSS INLAND AREAS.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
THE FORECAST AREA HAS GENERALLY REMAINED FREE OF ANY CONVECTION
FOR MOST OF THE AFTERNOON...WHILE SHOWERS AND THUNDERSTORMS HAVE
BECOME WIDESPREAD ELSEWHERE IN THE CAROLINAS AND GEORGIA. THE
CONVECTION ACROSS SOUTHERN GEORGIA AND NORTHERN FLORIDA HAS LIKELY
ROBBED SOME OF THE AVAILABLE MOISTURE TODAY...WHILE CLOUD COVER
HAS HELPED TO STABILIZE THE ATMOSPHERE SOME OVER THE FORECAST
AREA.
WATER VAPOR IMAGERY DEPICTS A RATHER HIGHLY AMPLIFIED UPPER LEVEL
TROUGH OVER THE OHIO VALLEY...WITH A POTENT SHORT WAVE ROTATING
AROUND THE BASE. THE SOUTHERN END OF THIS SHORT WAVE WILL MOVE
FROM THE SOUTHERN APPALACHIANS LATE THIS AFTERNOON TO THE COASTAL
PLAIN OF THE CAROLINAS TONIGHT.
PRECIPITATION WILL BE DIFFICULT TO FORECAST TONIGHT GIVEN COMPLEX
MESOSCALE AND SYNOPTIC FEATURES INFLUENCING CONVECTIVE FORMATION
AND MOVEMENT. HOWEVER...THERE SHOULD BE A GOOD CHANCE OF
CONVECTION THIS EVENING...FIRST OVER SOUTHEAST GA BASED ON CURRENT
RADAR TRENDS...THEN OVER SOUTHEAST SC AS THE SHORTWAVE AND
ASSOCIATED CONVECTION DROP SOUTHEAST TOWARD THE AREA. WHILE IT IS
POSSIBLE THAT THE CONVECTION AHEAD OF THE SHORT WAVE COULD
ORGANIZE INTO A MESOSCALE CONVECTIVE SYSTEM...THE TIMING COULD BE
TOO LATE TO TAKE ADVANTAGE OF WHATEVER MEAGER INSTABILITY IS IN
PLACE. THE FORECAST AREA REMAINS IN A SLIGHT RISK FOR SEVERE
WEATHER...BUT THINK ANY SEVERE THREAT WILL BE ISOLATED...WITH
DAMAGING WINDS AND MARGINALLY SEVERE HAIL POSSIBLE. FREQUENT
LIGHTNING AND LOCALLY HEAVY RAINFALL WILL ALSO ACCOMPANY ANY
THUNDERSTORMS.
CHANCES OF RAINFALL WILL COME TO AN END ACROSS INTERIOR SOUTHEAST
GA LATE TONIGHT AS THE SHORT WAVE MOVES TO THE COAST...HOWEVER
WILL MAINTAIN SLIGHT CHANCE OR LOW CHANCE POPS ELSEWHERE TO
ACCOUNT FOR ANY LINGERING PRECIPITATION.
A GOOD DEAL OF CLOUD COVER WILL LIMIT THE AMOUNT OF COOLING WHICH
WILL TAKE PLACE TONIGHT...AND EXPECT LOWS IN THE LOWER TO MID 70S
AWAY FROM THE COAST.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
A COLD FRONT APPEARS TO STALL AND DISSIPATE JUST NORTHWEST OF THE
FORECAST AREA ON THURSDAY. A SOUTHERLY FLOW SHOULD PERSIST AT THE
SURFACE...BUT THE LOW TO MID LEVEL FLOW SHOULD BECOME NORTHWEST
ALLOWING SOME DRIER AIR TO ADVECT INTO THE AREA. WHILE THE DEEP
MOISTURE WILL NO LONGER BE IN PLACE...THERE WILL BE ENOUGH LOW
LEVEL MOISTURE TO WARRANT FORECASTING A SLIGHT CHANCE OF
SHOWERS/THUNDERSTORMS DURING THE AFTERNOON ACROSS MUCH OF THE
FORECAST AREA. ANY CONVECTION WILL COME TO AN END WITH THE LOSS OF
DAYTIME HEATING THURSDAY EVENING.
DEPENDING ON THE AMOUNT OF RESIDUAL CLOUDINESS IN PLACE...HIGHS
COULD REACH THE LOWER 90S AWAY FROM THE COAST ON THURSDAY. LOWS
THURSDAY NIGHT SHOULD FALL INTO THE UPPER 60S TO LOWER 70S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A MEAN UPPER LEVEL TROUGH WILL PERSIST FROM EASTERN CANADA SOUTHWARD
THROUGH THE MID ATLANTIC STATES...WHILE MEAN UPPER LEVEL RIDGING
PERSISTS ACROSS THE SOUTHWEST AND SOUTHERN PLAINS STATES.
MODELS CONTINUE TO DIFFER IN THE DETAILS DURING THE EXTENDED
PERIOD. GFS IS MORE AGGRESSIVE WITH SHORTWAVE ENERGY ROUNDING THE
BASE OF THE UPPER TROUGH...MAINTAINING DEEPER LEVEL MOISTURE
ACROSS THE FORECAST AREA. DESPITE MODEL DISAGREEMENT IN SOME OF
THE TIMING AND STRENGTH OF SYNOPTIC FEATURES....THE GENERAL SURFACE
PATTERN IS CONSISTENT BETWEEN THE MODELS. AN ATLANTIC RIDGE WILL
LINGER OVER THE MARINE ZONES...WITH A SURFACE TROUGH PERSISTING
INLAND. A GRADUAL INCREASE IN MOISTURE THROUGH EARLY NEXT
WEEK...IN ADDITION TO THE SERIES OF SHORTWAVES MOVING INTO THE
SOUTHEAST STATES...WILL MAINTAIN A CHANCE OF SHOWERS AND
THUNDERSTORMS DURING THE AFTERNOON AND EARLY EVENING HOURS THROUGH
NEXT WEDNESDAY.
ANOTHER FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST LATE IN
THE WEEKEND THROUGH EARLY NEXT WEEK. CONSIDERING THE TIME OF YEAR
AND MODEL SOLUTIONS...THE FRONTAL BOUNDARY WILL LIKELY STALL JUST
NORTH OF THE REGION. LACKING ANY FRONTAL PASSAGE...SHOWER AND
THUNDERSTORM ACTIVITY IS EXPECTED TO REMAIN MOSTLY DIURNAL IN
NATURE. BEST CHANCE FOR CONVECTION WILL BE WITHIN SEABREEZE
FORCING AND INSTABILITY DURING THE AFTERNOON/EVENINGS...DIMINISHING
TO A SLIGHT CHANCE OR LESS OVERNIGHT.
AFTERNOON HEAT INDICES ARE EXPECTED TO TREND UPWARDS EACH DAY AS
LOW LEVEL MOISTURE INCREASES THROUGH THE PERIOD. HEAT INDICES IN SOME
LOCATIONS COULD EXCEED 105 DEGREES FROM SUNDAY THROUGH AT LEAST
TUESDAY...AS DEWPOINTS WILL REMAIN IN THE MID 70S DURING THE
AFTERNOON HOURS.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
MAIN CONCERN WILL BE POTENTIAL FOR THUNDERSTORM DEVELOPMENT INTO
THIS EVENING. WITH LOW CONFIDENCE IN TIMING AND COVERAGE...HAVE
JUST A MENTION OF CB UNTIL RADAR TRENDS BECOME MORE EVIDENT. WILL
CONTINUE TO MONITOR THE SITUATION.
FOR TONIGHT...FOG DEVELOPMENT SHOULD BE MINIMAL AS CLOUD COVER
WILL BE IN PLACE AND SURFACE WINDS WILL BE UP CLOSE TO 10 KNOTS
BEFORE SUBSIDING JUST BEFORE DAYBREAK. IF EITHER TERMINAL
EXPERIENCES ANY SHOWER ACTIVITY THIS EVENING...FOG MAY DEVELOP AND
REDUCE VISIBILITIES TO MVFR LEVELS DUE TO THE RESIDUAL MOISTURE.
EXTENDED AVIATION OUTLOOK...A CHANCE OF MVFR VSBYS EACH MORNING
DUE TO HIGH LOW LEVEL MOISTURE AND LIGHT WINDS...OTHERWISE VFR
CONDITIONS EXPECTED OUTSIDE OF MAINLY AFTERNOON/EVENING CONVECTION.
&&
.MARINE...
THE SURFACE PRESSURE GRADIENT HAS TIGHTENED SIGNIFICANTLY OVER THE
COASTAL WATERS THIS AFTERNOON AHEAD OF AN APPROACHING COLD FRONT
AND STRENGTHENING LEE-SIDE TROUGH. A SOUTH-SOUTHWEST SURGE HAS
DEVELOPED AS A RESULT...WITH SUSTAINED WINDS OF 15 TO 20 KT
ACROSS PORTIONS OF THE SOUTH CAROLINA NEAR SHORE WATERS AND THE
GEORGIA OFFSHORE WATERS...AND IN ASSOCIATION WITH ANY PASSING
OUTFLOW BOUNDARIES. THIS SURGE IS LIKELY TO CONTINUE...OR POSSIBLY
EVEN STRENGTHEN SOME INTO THE EARLY OVERNIGHT HOURS...BEFORE WINDS
SUBSIDE TO 10-15 KT LATE TONIGHT. WILL NEED TO CLOSELY MONITOR
CONDITIONS THIS EVENING AS WINDS ANY STRONGER WOULD REQUIRE A
SMALL CRAFT ADVISORY.
THE MARINE ZONES WILL REMAIN ON THE WESTERN PERIPHERY OF ATLANTIC
HIGH PRESSURE THROUGH THE EXTENDED PERIOD. WINDS WILL GENERALLY
MAINTAIN A SOUTHERLY COMPONENT INTO NEXT WEEK. SPEEDS WILL REMAIN
AT OR BELOW 15 KNOTS OUTSIDE OF ANY THUNDERSTORM ACTIVITY...WITH
SEAS AT OR BELOW 4 FEET.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
JAQ/WMM
000
FXUS62 KFFC 231934
AFDFFC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
334 PM EDT WED JUL 23 2008
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
FRONTAL BOUNDARY EVIDENT ON VISIBLE SATELLITE THIS AFTERNOON
ACROSS TENNESSEE. SHOWERS AND THUNDERSTORMS BEGINNING TO DEVELOP
ALONG FRONT...AS WELL AS ACROSS PORTIONS OF CENTRAL GEORGIA IN
ASSOCIATION WITH LEFTOVER OUTFLOW BOUNDARY FROM CONVECTION ON
TUESDAY. OVERALL...CONVECTION HAS BEEN SLOW TO DEVELOP TODAY
RELATIVE TO TUESDAY...DUE TO CLOUD COVER KEEPING THE LOWER LEVELS
OF THE ATMOSPHERE RELATIVELY COOL AND STABLE. STILL EXPECT CHANCES
FOR SHOWERS AND THUNDERSTORMS TO INCREASE ACROSS ALL OF NORTH AND
CENTRAL GEORGIA LATE THIS AFTERNOON INTO THE EVENING AS FRONT
APPROACHES. HIGHEST POPS WILL BE ACROSS CENTRAL GEORGIA WHERE
BETTER INSTABILITY AND SURFACE TROUGH ARE IN PLACE. THREAT FOR
SEVERE THUNDERSTORMS APPEARS LESS THIS EVENING RELATIVE TO TUESDAY
AS FREEZING LEVEL HAS RISEN SLIGHTLY AND ATMOSPHERE IS MORE
SATURATED...WITH LESS POTENTIAL FOR DOWNBURSTS.
NAM/GFS HAVE DIFFERENT SCENARIOS FOR WHAT THE FRONTAL BOUNDARY
WILL DO ONCE IT ARRIVES IN GEORGIA. NAM PUSHES THE FRONT THROUGH
THE STATE ALL THE WAY THROUGH GEORGIA AND INTO FLORIDA...WHILE
THE GFS STALLS THE BOUNDARY ACROSS CENTRAL GEORGIA...CONTINUING
CHANCES FOR SHOWERS AND THUNDERSTORMS FOR THURSDAY AND EVEN
POSSIBLY FRIDAY. LEANED HEAVILY TOWARDS THE GFS SOLUTION AS
CHANCES OF A FRONT MAKING IT ALL THE WAY TO FLORIDA IN LATE JULY
ARE LOW. ON FRIDAY THE GFS DEVELOPS A SIGNIFICANT AREA OF
CONVECTION...POSSIBLY AN MCS...ACROSS THE TENNESSEE RIVER VALLEY
AND RAPIDLY PUSHES THE SYSTEM INTO ALABAMA AND WEST GEORGIA FRIDAY
EVENING. NAM SHOWS A SIMILAR SYSTEM...HOWEVER MUCH FARTHER
NORTH...AND WITH A MORE EASTERLY TRAJECTORY ACROSS THE OHIO RIVER
VALLEY. LEANED TOWARDS NAM SOLUTION IN THIS CASE AS THAT IS A MORE
FAVORED AREA FOR SUCH SYSTEMS. HOWEVER DID SHOW SOME INCREASE IN
POPS ACROSS WEST GEORGIA FRIDAY AFTERNOON AS A COMPROMISE BETWEEN
THE TWO SOLUTIONS. GENERALLY STAYED CLOSE TO MOS ON TEMPERATURES.
SOME DRIER AIR MAY WORK INTO NORTH GEORGIA TONIGHT WITH COOLER
TEMPERATURES THAN HAVE BEEN SEEN THERE IN SEVERAL DAYS. TEMPERATURES
SHOULD QUICKLY WARM TO THE 90S ON THURSDAY...PARTICULARLY ACROSS
NORTH GEORGIA WHERE H8 TEMPERATURES APPROACH +20 DEGREES C.
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
NO SIGNIFICANT CHANGE OF PATTERN APPEARS LIKELY THROUGH THE
EXTENDED PERIOD. UPPER RIDGE REMAINS ANCHORED ACROSS THE SOUTH
CENTRAL PART OF THE UNITED STATES...EVENTUALLY GETTING PUSHED
FARTHER WEST...ACROSS THE DESERT SOUTHWEST EARLY NEXT WEEK. THIS
SCENARIO WILL KEEP GEORGIA IN NORTHWEST FLOW THROUGH THE EXTENDED
PERIOD WITH CHANCES FOR PRECIP EVERY DAY AS DISTURBANCES RIDE THE
NORTHWEST FLOW ALONG THE PERIPHERY OF THE UPPER-RIDGE. THIS
PATTERN SHOULD KEEP TEMPERATURES IN THE EXTENDED NEAR SEASONAL
AVERAGES.
&&
.FIRE WEATHER...
FRONTAL BOUNDARY APPROACHING NORTH AND CENTRAL GEORGIA
TONIGHT...INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS. FRONT
FRONT SHOULD STALL SOMEWHERE ACROSS CENTRAL GEORGIA ON
THURSDAY...RESULTING IN CONTINUED CHANCES FOR SHOWERS AND
THUNDERSTORMS ACROSS CENTRAL GEORGIA...WITH DRIER CONDITIONS
ACROSS THE NORTHERN PORTION OF THE STATE.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 67 94 67 92 68 / 30 10 5 20 10
ATLANTA 68 90 71 90 70 / 20 10 5 20 20
BLAIRSVILLE 62 88 61 88 64 / 20 10 10 20 20
CARTERSVILLE 63 91 62 89 67 / 20 10 10 20 20
COLUMBUS 71 91 73 92 73 / 40 30 20 30 20
GAINESVILLE 66 89 66 88 69 / 30 10 5 20 20
MACON 70 91 69 94 71 / 40 30 20 20 10
ROME 65 93 67 92 69 / 20 10 10 30 20
PEACHTREE CITY 64 91 65 90 67 / 20 10 5 20 20
VIDALIA 71 92 69 92 70 / 50 30 20 20 10
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MSR
000
FXUS62 KCAE 231911
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
311 PM EDT WED JUL 23 2008
.SYNOPSIS...
FRONTAL SYSTEM APPROACHING FROM THE NORTHWEST WILL BRING INCREASED
CHANCES OF PRECIPITATION THIS EVENING. HIGH PRESSURE WILL BUILD
IN THURSDAY AND FRIDAY AHEAD OF ANOTHER COLD FRONT THAT WILL REACH
THE AREA ON SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
SURFACE TROUGH WILL PROVIDE FORCING FOR DEVELOPMENT FOR POSSIBLE SEVERE
THUNDERSTORMS THIS AFTERNOON AND EVENING. ADDITIONALLY...SPC HAS
SC AND GA IN A SLIGHT RISK FOR SEVERE STORMS. MODERATE TO STRONG
INSTABILITY IN PLACE ACROSS THE REGION WITH LI VALUES AROUND
-6. PWS UPWARDS OF 1.75 INCHES WITH WEAK WIND SHEAR. SBCAPE AROUND
1500 J/KG ACROSS THE SOUTHERN AND CENTRAL MIDLANDS AND NEAR 2000
J/KG IN THE NORTH CENTRAL MIDLANDS. GREATEST THREAT POTENTIAL FROM
THUNDERSTORMS WILL BE HAIL AND LOCALLY HEAVY RAINFALL. HAVE KEPT
LIKELY POPS BUT INCREASED TO CATEGORICAL IN THE NORTH CENTRAL AREA
DUE TO BEST UPPER LEVEL SUPPORT FOR CONVECTION.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
FRONTAL SYSTEM WILL SLOWLY CROSS THE AREA DURING THE DAY ON THURSDAY
AND STALL OFF THE COAST THURSDAY EVENING AND INTO FRIDAY. HIGH
PRESSURE WILL BUILD IN BEHIND THE FRONT ON FRIDAY. DRY AIRMASS IN
PLACE WILL KEEP POPS LOW THROUGH THE PERIOD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MODELS ARE IN AGREEMENT WITH ANOTHER FRONT APPROACHING SATURDAY
EVENING THAT WILL STALL ACROSS THE REGION...OR JUST OFF THE
COAST...THROUGH MID WEEK. HAVE DECIDED TO KEEP ISOLATED CHANCE
POPS THROUGH WEDNESDAY AS DIURNAL THUNDERSTORM ACTIVITY WILL BE POSSIBLE.
TEMPS FOR THE WEEKEND WILL BE SLIGHTLY ABOVE CLIMATOLOGY BUT WILL
BE BACK TO NORMAL MONDAY THROUGH WEDNESDAY.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
WEAK SFC TROUGH DRAPED ACROSS THE STATE WITH COLD FRONT APPROACHING
FROM THE OH VALLEY. GENERALLY VFR CONDITIONS THROUGH THE TAF PERIOD
EXCEPT SOME MVFR CIGS/VSBYS IN VCNTY OF STRONGER STORMS. GIVEN
TIMING ISSUES WILL JUST MENTION CB IN TAFS. CONVECTION SHOULD
SUBSIDE DURING THE EVENING HOURS ESPECIALLY AFTER 04Z. SOME CLOUDS
WILL LINGER OVERNIGHT WITH SKIES BECOMING MOSTLY CLEAR AFTER SUNRISE
THURSDAY AS THE COLD FRONT PUSHES TOWARDS THE COAST.
EXTENDED OUTLOOK...AT THIS TIME NO SIGNIFICANT IMPACTS TO AVIATION
EXPECTED THURSDAY THROUGH SUNDAY.
$$
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...DG
NEAR TERM...DG
SHORT TERM...DG
LONG TERM...DG
AVIATION...BC
000
FXUS62 KCHS 231744
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
144 PM EDT WED JUL 23 2008
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL PERSIST ACROSS INLAND AREAS TODAY.
A DECAYING FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST
TONIGHT AND STALL JUST NORTHWEST OF THE AREA THURSDAY BEFORE
DISSIPATING. ATLANTIC HIGH PRESSURE WILL REMAIN THROUGH NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SATELLITE IMAGERY SHOWS PLENTY OF RESIDUAL CLOUDINESS OVER THE
AREA THIS MORNING FROM YESTERDAY/S CONVECTION...ESPECIALLY OVER
SOUTHEAST GEORGIA. WHILE THERE ARE AND WILL CONTINUE TO BE SOME
BREAKS IN THE MID-HIGH LEVEL CLOUD COVER THROUGH THE DAY...EXPECT
ANY AREAS WITH CLEARING TO QUICKLY FILL IN WITH A DECENT CUMULUS
FIELD THIS AFTERNOON AS CONVECTIVE TEMPERATURES ARE REACHED.
A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY.
MEANWHILE...A LEE-SIDE TROUGH IS IN PLACE FROM THE PIEDMONT OF
NORTH AND SOUTH CAROLINA TO CENTRAL GEORGIA. IN ADDITION...THERE ARE
MANY OUTFLOW BOUNDARIES IN PLACE ACROSS THE REGION. ALL OF THESE
BOUNDARIES WILL ACT TO BE A FOCUS FOR CONVECTION AS THE AFTERNOON
PROGRESSES. LIFT WILL BE ENHANCED AS THE TRAILING END OF A POTENT
SHORT WAVE OVER THE OHIO VALLEY SHIFTS ACROSS THE SOUTHERN
APPALACHIANS THIS AFTERNOON THEN CONTINUES TOWARD THE COAST LATE
IN THE DAY.
ISOLATED CONVECTION WILL BE POSSIBLE THROUGH MIDDAY...THEN EXPECT
THE COVERAGE TO INCREASE TO SCATTERED OR NUMEROUS BY LATE THIS
AFTERNOON. THE CONVECTION COULD BECOME MORE ORGANIZED LATE THIS
AFTERNOON AS THE SHORT WAVE APPROACHES...POSSIBLY DEVELOPING INTO A
MESOSCALE CONVECTIVE SYSTEM WHICH COULD THEN SHIFT SOUTHEAST
THROUGH THE AREA.
THE 12Z KCHS SOUNDING SHOWS WEAK TO MODERATE INSTABILITY IN PLACE
ACROSS THE AREA. CAPE VALUES ARE AROUND 3000 J/KG WHILE TOTAL
TOTALS ARE AROUND 51. LAPSE RATES ARE MARGINAL AT BEST...AT AROUND
6 C/KM. WIND FIELDS ARE NOT ALL THAT IMPRESSIVE...BUT MODEL
SOUNDINGS DO SHOW AN INVERTED-V STRUCTURE SUGGESTING SOME LOCALLY
DAMAGING WINDS ARE POSSIBLE IN ANY THUNDERSTORM WHICH BECOMES
SEVERE. WET BULB ZERO HEIGHTS ARE OVER 13000 FT...SO MARGINALLY
SEVERE HAIL SHOULD POSSIBLE IN ONLY THE STRONGEST STORMS.
PRECIPITABLE WATER VALUES NEAR 2 INCHES COULD RESULT IN LOCALLY
HEAVY RAINFALL...AND LOCALIZED FLOODING WOULD BE POSSIBLE UNDER SLOW
MOVING STORMS. SINCE THE FORECAST AREA HAS BEEN PLACED IN A SLIGHT
RISK BY THE STORM PREDICTION CENTER...WILL KEEP THE MENTION OF
ISOLATED SEVERE THUNDERSTORMS IN THE HAZARDOUS WEATHER OUTLOOK.
HAVE ALSO ENHANCED THE WORDING IN THE FORECAST TO SHOW GUSTY
WINDS...HEAVY RAIN AND FREQUENT LIGHTNING ARE ALL POSSIBLE THIS
AFTERNOON.
HIGHS WILL BE TEMPERED BY THE CLOUD COVER...RANGING FROM THE
LOWER 90S INLAND TO THE MID 80S CLOSER TO THE COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
SHOWER AND THUNDERSTORM COVERAGE THIS EVENING WILL BE DEPENDENT
ON THE DEGREE OF CONVECTIVE ORGANIZATION THAT CAN OCCUR THIS
AFTERNOON. WILL KEEP 50-60 PERCENT POPS GOING THROUGH LATE EVENING
AWAY FROM THE COAST WITH POPS TRENDING INTO THE CHANCE CATEGORY
ACROSS THE COASTAL WATERS. WILL KEEP AT LEAST A SLIGHT CHANCE OF
RAIN GOING AFTER MIDNIGHT AS A DECAYING FRONTAL BOUNDARY LINKS UP
WITH THE LEE-SIDE TROUGH AND MEANDERS TOWARDS THE COAST. LOWS
TONIGHT WILL BE IN THE LOWER 70S...EXCEPT MID 70S NEAR THE COAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
A MEAN UPPER LEVEL TROF WILL PERSIST FROM EASTERN
CANADA SOUTHWARD THROUGH THE EASTERN PORTION OF THE COUNTY FROM
THURSDAY THROUGH TUESDAY WHILE MEAN UPPER LEVEL RIDGING PERSISTS
ACROSS THE ROCKIES. AT THE SURFACE...A LEE SIDE TROF TO THE
NORTHWEST OF OUR COUNTY WARNING AREA WILL PERSIST FOR MUCH OF THE
TIME.
THERE ARE SIGNIFICANT DIFFERENCES ON THE HANDLING OF A WEAK COLD
FRONT ON THURSDAY. THE NAM BRINGS THE FRONT THROUGH MUCH OF OUR
FORECAST AREA ON THURSDAY BEFORE IT GETS HUNG UP NEAR THE COAST BY
LATE IN THE DAY. THE GFS STALLS THE FRONT OUT FROM CENTRAL NORTH
CAROLINA TO CENTRAL GEORGIA THURSDAY BEFORE QUICKLY LIFTING IT BACK
NORTH. RECENT TRENDS OF THE GFS HAVE BEEN TO STALL THE FRONT OUT A
LITTLE FARTHER NORTH. ECMWF SOLUTION IS VERY SIMILAR TO THAT OF THE
GFS.FEELING IS THAT GFS/ECMWF HAS A BETTER HANDLE ON THE FRONTAL
POSITION AND MOVEMENT AS IT IS QUITE DIFFICULT TO GET A FRONT
THROUGH HERE DURING THE PEAK OF SUMMER. IN ADDITION...FEEL THAT GFS
HAS A BETTER HANDLE ON THE MOISTURE FIELDS AND A THREAT FOR
PRECIPITATION THURSDAY AND FRIDAY AFTERNOON/EVENING AS IT APPEARS
THAT THE NAM DRIES THINGS OUT TOO MUCH. AS A RESULT...GENERALLY
FOLLOWED THE GFS/MAV GUIDANCE FAIRLY CLOSELY THROUGH THE PERIOD.
EXPECT THE SEA BREEZE TO BE ACTIVE ON MOST DAYS AND GENERALLY HAVE
POPS NOT TOO FAR FROM THE CLIMATOLOGICAL NORM. THINK THE STRONG AREA
OF LOW PRESSURE FORECAST BY 00Z GFS TO MOVE THROUGH THE CAROLINAS ON
TUESDAY SEEMS TO BE OVERDONE.
AFTERNOON HEAT INDICES SHOULD BE NEAR 100 AWAY FROM THE COAST ON
THURSDAY AND THEN RISE A LITTLE EACH DAY AS TEMPERATURES AND
ESPECIALLY DEWPOINT TEMPERATURES SLOWLY TREND UPWARDS. FROM SUNDAY
THROUGH TUESDAY...HEAT INDICES IS SOME LOCATIONS ARE FORECAST TO
EXCEED 105 DEGREES AS DEWPOINTS IN THE MID TO PERHAPS EVEN UPPER 70S
WILL BE COMMON.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VISIBLE SATELLITE SHOWS INCREASING CLOUDINESS OVER THE AREA AND IS
EXPECTED TO CONTINUE THROUGH THE AFTERNOON. MAIN CONCERN WILL BE
THUNDERSTORM DEVELOPMENT ALONG THE SEA BREEZE. EXPECT KCHS HAS THE
HIGHER CHANCE FOR SEEING ANY ACTIVITY INTO THIS EVENING. WITH LOW
CONFIDENCE IN TIMING AND LOCATION HAVE JUST MENTION OF CB UNTIL
RADAR TRENDS BECOME MORE EVIDENT. WILL CONTINUE TO MONITOR THE
SITUATION.
FOR TONIGHT...FOG DEVELOPMENT SHOULD BE MINIMAL AS CLOUD COVER
WILL BE IN PLACE AND SURFACE WINDS WILL BE UP CLOSE TO 10 KNOTS
BEFORE SUBSIDING JUST BEFORE DAYBREAK. AGAIN...IF KCHS EXPERIENCES
ANY SHOWER ACTIVITY LATE THIS AFTERNOON AND EVENING...FOG MAY
DEVELOP AND REDUCE VISIBILITIES TO MVFR FROM THE LEFT OVER
MOISTURE.
EXTENDED AVIATION OUTLOOK...A CHANCE OF MVFR VSBYS EACH MORNING
DUE TO HIGH LOW LEVEL MOISTURE AND LIGHT WINDS...OTHERWISE VFR
CONDITIONS EXPECTED OUTSIDE OF MAINLY AFTERNOON/EVENING CONVECTION.
&&
.MARINE...
A SOUTHERLY WIND REGIME WILL PERSIST THROUGH TONIGHT AS A DECAYING
FRONTAL BOUNDARY APPROACHES FROM THE NORTHWEST. WINDS WILL REMAIN AT
15 KNOTS OR LESS WITH SEAS 4 FT OR LESS.
THE PERIOD FROM THURSDAY THROUGH SUNDAY WILL BE QUITE TRANQUIL
WITH A RELATIVELY WEAK PRESSURE GRADIENT RESULTING SOUTH TO
SOUTHWESTERLY WINDS OF 15 KNOTS OR LESS. SEAS SHOULD MAINLY BE
FROM 2 TO 3 FEET...WITH SOME 4 FOOT SEAS POSSIBLE MAINLY IN AMZ350
THIS WEEKEND.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
000
FXUS62 KCAE 231718
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
117 PM EDT WED JUL 23 2008
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION LATE TODAY...BRINGING WITH
IT ANOTHER CHANCE FOR PRECIPITATION WEDNESDAY AFTERNOON INTO
WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD INTO THE AREA THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MOSTLY CLEAR SKIES EXPECTED.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
WATER VAPOR AND MODELS SHOW VIGOROUS SHORT WAVE MOVING SOUTHEAST
INTO THE TN VALLEY. A SECOND REINFORCING SHORTWAVE IS DRIVING
SOUTH INTOT HE OHIO VALLEY AND WILL CONBINE WITH THE OTHER OVER
THE CAROLINAS AND VIRGINIA. FAIR TO GOOD UPPER LEVEL DYNAMICS AND
DEEP MOISTURE WILL LIKELY TRIGGER THE DEVELOPMENT OF A LINE OF
CONVECTION JUST AHEAD OF THE COLD FRONT BY LATE AFTERNOON. SPC HAS
SC IN A SLIGHT RISK FOR SEVERE STORMS. THE NAM AND LOCAL WRF
MODELS HAVE THE FRONT REACHING THE COAST BY THURSDAY MORNING WITH
HIGH PRESSURE BUILDING INTO THE AREA ON THURSDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL BE OVER THE AREA FRIDAY BUT MOISTURE WILL
RETURN OVER THE WEEKEND AND INTO NEXT WEEK. MODELS KEEP A WEAK
TROF OVER THE AREA THROUGH THE EXTENDED PERIOD WITH A DECENT
CHANGE OF PRECIP MONDAY AND TUESDAY AS ANOTHER FRONT APPROACHES.
TEMPS WILL BE CLOSE TO NORMAL.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
WEAK SFC TROUGH DRAPED ACROSS THE STATE WITH COLD FRONT APPROACHING
FROM THE OH VALLEY. GENERALLY VFR CONDITIONS THROUGH THE TAF PERIOD
EXCEPT SOME MVFR CIGS/VSBYS IN VCNTY OF STRONGER STORMS. GIVEN
TIMING ISSUES WILL JUST MENTION CB IN TAFS. CONVECTION SHOULD
SUBSIDE DURING THE EVENING HOURS ESPECIALLY AFTER 04Z. SOME CLOUDS
WILL LINGER OVERNIGHT WITH SKIES BECOMING MOSTLY CLEAR AFTER SUNRISE
THURSDAY AS THE COLD FRONT PUSHES TOWARDS THE COAST.
EXTENDED OUTLOOK...AT THIS TIME NO SIGNIFICANT IMPACTS TO AVIATION
EXPECTED THURSDAY THROUGH SUNDAY.
$$
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCAE 231718
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
117 PM EDT WED JUL 23 2008
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION LATE TODAY...BRINGING WITH
IT ANOTHER CHANCE FOR PRECIPITATION WEDNESDAY AFTERNOON INTO
WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD INTO THE AREA THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MOSTLY CLEAR SKIES EXPECTED.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
WATER VAPOR AND MODELS SHOW VIGOROUS SHORT WAVE MOVING SOUTHEAST
INTO THE TN VALLEY. A SECOND REINFORCING SHORTWAVE IS DRIVING
SOUTH INTOT HE OHIO VALLEY AND WILL CONBINE WITH THE OTHER OVER
THE CAROLINAS AND VIRGINIA. FAIR TO GOOD UPPER LEVEL DYNAMICS AND
DEEP MOISTURE WILL LIKELY TRIGGER THE DEVELOPMENT OF A LINE OF
CONVECTION JUST AHEAD OF THE COLD FRONT BY LATE AFTERNOON. SPC HAS
SC IN A SLIGHT RISK FOR SEVERE STORMS. THE NAM AND LOCAL WRF
MODELS HAVE THE FRONT REACHING THE COAST BY THURSDAY MORNING WITH
HIGH PRESSURE BUILDING INTO THE AREA ON THURSDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL BE OVER THE AREA FRIDAY BUT MOISTURE WILL
RETURN OVER THE WEEKEND AND INTO NEXT WEEK. MODELS KEEP A WEAK
TROF OVER THE AREA THROUGH THE EXTENDED PERIOD WITH A DECENT
CHANGE OF PRECIP MONDAY AND TUESDAY AS ANOTHER FRONT APPROACHES.
TEMPS WILL BE CLOSE TO NORMAL.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
WEAK SFC TROUGH DRAPED ACROSS THE STATE WITH COLD FRONT APPROACHING
FROM THE OH VALLEY. GENERALLY VFR CONDITIONS THROUGH THE TAF PERIOD
EXCEPT SOME MVFR CIGS/VSBYS IN VCNTY OF STRONGER STORMS. GIVEN
TIMING ISSUES WILL JUST MENTION CB IN TAFS. CONVECTION SHOULD
SUBSIDE DURING THE EVENING HOURS ESPECIALLY AFTER 04Z. SOME CLOUDS
WILL LINGER OVERNIGHT WITH SKIES BECOMING MOSTLY CLEAR AFTER SUNRISE
THURSDAY AS THE COLD FRONT PUSHES TOWARDS THE COAST.
EXTENDED OUTLOOK...AT THIS TIME NO SIGNIFICANT IMPACTS TO AVIATION
EXPECTED THURSDAY THROUGH SUNDAY.
$$
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
000
FXUS62 KCHS 231533
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1133 AM EDT WED JUL 23 2008
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL PERSIST ACROSS INLAND AREAS TODAY.
A DECAYING FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST
TONIGHT AND STALL JUST NORTHWEST OF THE AREA THURSDAY BEFORE
DISSIPATING. ATLANTIC HIGH PRESSURE WILL REMAIN THROUGH NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SATELLITE IMAGERY SHOWS PLENTY OF RESIDUAL CLOUDINESS OVER THE
AREA THIS MORNING FROM YESTERDAY/S CONVECTION...ESPECIALLY OVER
SOUTHEAST GEORGIA. WHILE THERE ARE AND WILL CONTINUE TO BE SOME
BREAKS IN THE MID-HIGH LEVEL CLOUD COVER THROUGH THE DAY...EXPECT
ANY AREAS WITH CLEARING TO QUICKLY FILL IN WITH A DECENT CUMULUS
FIELD THIS AFTERNOON AS CONVECTIVE TEMPERATURES ARE REACHED.
A WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY.
MEANWHILE...A LEE-SIDE TROUGH IS IN PLACE FROM THE PIEDMONT OF
NORTH AND SOUTH CAROLINA TO CENTRAL GEORGIA. IN ADDITION...THERE ARE
MANY OUTFLOW BOUNDARIES IN PLACE ACROSS THE REGION. ALL OF THESE
BOUNDARIES WILL ACT TO BE A FOCUS FOR CONVECTION AS THE AFTERNOON
PROGRESSES. LIFT WILL BE ENHANCED AS THE TRAILING END OF A POTENT
SHORT WAVE OVER THE OHIO VALLEY SHIFTS ACROSS THE SOUTHERN
APPALACHIANS THIS AFTERNOON THEN CONTINUES TOWARD THE COAST LATE
IN THE DAY.
ISOLATED CONVECTION WILL BE POSSIBLE THROUGH MIDDAY...THEN EXPECT
THE COVERAGE TO INCREASE TO SCATTERED OR NUMEROUS BY LATE THIS
AFTERNOON. THE CONVECTION COULD BECOME MORE ORGANIZED LATE THIS
AFTERNOON AS THE SHORT WAVE APPROACHES...POSSIBLY DEVELOPING INTO A
MESOSCALE CONVECTIVE SYSTEM WHICH COULD THEN SHIFT SOUTHEAST
THROUGH THE AREA.
THE 12Z KCHS SOUNDING SHOWS WEAK TO MODERATE INSTABILITY IN PLACE
ACROSS THE AREA. CAPE VALUES ARE AROUND 3000 J/KG WHILE TOTAL
TOTALS ARE AROUND 51. LAPSE RATES ARE MARGINAL AT BEST...AT AROUND
6 C/KM. WIND FIELDS ARE NOT ALL THAT IMPRESSIVE...BUT MODEL
SOUNDINGS DO SHOW AN INVERTED-V STRUCTURE SUGGESTING SOME LOCALLY
DAMAGING WINDS ARE POSSIBLE IN ANY THUNDERSTORM WHICH BECOMES
SEVERE. WET BULB ZERO HEIGHTS ARE OVER 13000 FT...SO MARGINALLY
SEVERE HAIL SHOULD POSSIBLE IN ONLY THE STRONGEST STORMS.
PRECIPITABLE WATER VALUES NEAR 2 INCHES COULD RESULT IN LOCALLY
HEAVY RAINFALL...AND LOCALIZED FLOODING WOULD BE POSSIBLE UNDER SLOW
MOVING STORMS. SINCE THE FORECAST AREA HAS BEEN PLACED IN A SLIGHT
RISK BY THE STORM PREDICTION CENTER...WILL KEEP THE MENTION OF
ISOLATED SEVERE THUNDERSTORMS IN THE HAZARDOUS WEATHER OUTLOOK.
HAVE ALSO ENHANCED THE WORDING IN THE FORECAST TO SHOW GUSTY
WINDS...HEAVY RAIN AND FREQUENT LIGHTNING ARE ALL POSSIBLE THIS
AFTERNOON.
HIGHS WILL BE TEMPERED BY THE CLOUD COVER...RANGING FROM THE
LOWER 90S INLAND TO THE MID 80S CLOSER TO THE COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
SHOWER AND THUNDERSTORM COVERAGE THIS EVENING WILL BE DEPENDENT
ON THE DEGREE OF CONVECTIVE ORGANIZATION THAT CAN OCCUR THIS
AFTERNOON. WILL KEEP 50-60 PERCENT POPS GOING THROUGH LATE EVENING
AWAY FROM THE COAST WITH POPS TRENDING INTO THE CHANCE CATEGORY
ACROSS THE COASTAL WATERS. WILL KEEP AT LEAST A SLIGHT CHANCE OF
RAIN GOING AFTER MIDNIGHT AS A DECAYING FRONTAL BOUNDARY LINKS UP
WITH THE LEE-SIDE TROUGH AND MEANDERS TOWARDS THE COAST. LOWS
TONIGHT WILL BE IN THE LOWER 70S...EXCEPT MID 70S NEAR THE COAST.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
A MEAN UPPER LEVEL TROF WILL PERSIST FROM EASTERN
CANADA SOUTHWARD THROUGH THE EASTERN PORTION OF THE COUNTY FROM
THURSDAY THROUGH TUESDAY WHILE MEAN UPPER LEVEL RIDGING PERSISTS
ACROSS THE ROCKIES. AT THE SURFACE...A LEE SIDE TROF TO THE
NORTHWEST OF OUR COUNTY WARNING AREA WILL PERSIST FOR MUCH OF THE
TIME.
THERE ARE SIGNIFICANT DIFFERENCES ON THE HANDLING OF A WEAK COLD
FRONT ON THURSDAY. THE NAM BRINGS THE FRONT THROUGH MUCH OF OUR
FORECAST AREA ON THURSDAY BEFORE IT GETS HUNG UP NEAR THE COAST BY
LATE IN THE DAY. THE GFS STALLS THE FRONT OUT FROM CENTRAL NORTH
CAROLINA TO CENTRAL GEORGIA THURSDAY BEFORE QUICKLY LIFTING IT BACK
NORTH. RECENT TRENDS OF THE GFS HAVE BEEN TO STALL THE FRONT OUT A
LITTLE FARTHER NORTH. ECMWF SOLUTION IS VERY SIMILAR TO THAT OF THE
GFS.FEELING IS THAT GFS/ECMWF HAS A BETTER HANDLE ON THE FRONTAL
POSITION AND MOVEMENT AS IT IS QUITE DIFFICULT TO GET A FRONT
THROUGH HERE DURING THE PEAK OF SUMMER. IN ADDITION...FEEL THAT GFS
HAS A BETTER HANDLE ON THE MOISTURE FIELDS AND A THREAT FOR
PRECIPITATION THURSDAY AND FRIDAY AFTERNOON/EVENING AS IT APPEARS
THAT THE NAM DRIES THINGS OUT TOO MUCH. AS A RESULT...GENERALLY
FOLLOWED THE GFS/MAV GUIDANCE FAIRLY CLOSELY THROUGH THE PERIOD.
EXPECT THE SEA BREEZE TO BE ACTIVE ON MOST DAYS AND GENERALLY HAVE
POPS NOT TOO FAR FROM THE CLIMATOLOGICAL NORM. THINK THE STRONG AREA
OF LOW PRESSURE FORECAST BY 00Z GFS TO MOVE THROUGH THE CAROLINAS ON
TUESDAY SEEMS TO BE OVERDONE.
AFTERNOON HEAT INDICES SHOULD BE NEAR 100 AWAY FROM THE COAST ON
THURSDAY AND THEN RISE A LITTLE EACH DAY AS TEMPERATURES AND
ESPECIALLY DEWPOINT TEMPERATURES SLOWLY TREND UPWARDS. FROM SUNDAY
THROUGH TUESDAY...HEAT INDICES IS SOME LOCATIONS ARE FORECAST TO
EXCEED 105 DEGREES AS DEWPOINTS IN THE MID TO PERHAPS EVEN UPPER 70S
WILL BE COMMON.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
KCHS - LIGHT FOG/HAZE WILL BURN OFF BY 12Z. CUMULUS WILL DEVELOP BY
LATE MORNING AND COULD BECOME RATHER EXTENSIVE AFTER 16Z. STILL
LOOKING FOR ISOLATED SHOWERS AND TSTMS TO FIRE ALONG THE SEA
BREEZE JUST NORTH OF THE AIRPORT BY 16Z. TOUGH CALL ON WHETHER
THIS ACTIVITY COULD DIRECTLY IMPACT THE TERMINAL SO A MENTION OF
CB/S WILL BE MAINTAINED. WILL HAVE TO CAREFULLY WATCH TO SEE IF
ANY ACTIVITY THAT FIRES OVER THE MIDLANDS MAKES A RUN FOR THE
COAST.
KSAV - CONVECTIVE DEBRIS HIGH CLOUDINESS IS HOLDING FIRM AND MAY
TAKE ANOTHER HOUR TO TWO BEFORE BREAKING. SCATTERED SHOWERS AND
THUNDERSTORMS WILL LIKELY FIRE AHEAD OF THE SEA BREEZE THIS
AFTERNOON. THE LATEST SHORT TERM GUIDANCE SUGGESTS TSTM COVERAGE
MAY BE GREATEST NEAR THE TERMINAL BETWEEN 21-24Z SO A TEMPO GROUP
FOR TSRA WILL BE INCLUDED WITH THE 12Z TAF SET. ADJUSTMENTS MAY
BE NEEDED THROUGH THE DAY ONCE MORE DEFINITIVE CONVECTIVE TRENDS
ARE ESTABLISHED.
EXTENDED AVIATION OUTLOOK...A CHANCE OF MVFR VSBYS EACH MORNING
DUE TO HIGH LOW LEVEL MOISTURE AND LIGHT WINDS...OTHERWISE VFR
CONDITIONS EXPECTED OUTSIDE OF MAINLY AFTERNOON/EVENING CONVECTION.
&&
.MARINE...
A SOUTHERLY WIND REGIME WILL PERSIST THROUGH TONIGHT AS A DECAYING
FRONTAL BOUNDARY APPROACHES FROM THE NORTHWEST. WINDS WILL REMAIN AT
15 KNOTS OR LESS WITH SEAS 4 FT OR LESS.
THE PERIOD FROM THURSDAY THROUGH SUNDAY WILL BE QUITE TRANQUIL
WITH A RELATIVELY WEAK PRESSURE GRADIENT RESULTING SOUTH TO
SOUTHWESTERLY WINDS OF 15 KNOTS OR LESS. SEAS SHOULD MAINLY BE
FROM 2 TO 3 FEET...WITH SOME 4 FOOT SEAS POSSIBLE MAINLY IN AMZ350
THIS WEEKEND.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
JAQ
000
FXUS62 KCHS 231122
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
722 AM EDT WED JUL 23 2008
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL PERSIST ACROSS INLAND AREAS TODAY.
A DECAYING FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST
TONIGHT AND STALL JUST NORTHWEST OF THE AREA THURSDAY BEFORE
DISSIPATING. ATLANTIC HIGH PRESSURE WILL REMAIN THROUGH NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A NUMBER OF WELL DEFINED OUTFLOW BOUNDARIES CAN BE SEEN ACROSS THE
SOUTH CAROLINA UPSTATE...MIDLANDS AND THE NORTH CAROLINA PIEDMONT
EARLY THIS MORNING. THESE BOUNDARIES ARE EMBEDDED WITHIN A BROAD
LEE-SIDE TROUGH WHICH STRETCHES FROM CENTRAL GEORGIA THROUGH THE
PIEDMONT AREAS OF NORTH AND SOUTH CAROLINAS. ALL OF THESE BOUNDARIES
WILL SERVE AS FOCI FOR SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ACROSS MUCH OF THE SOUTHEAST U.S. THIS AFTERNOON AND
EVENING AS THE TAIL END OF A POTENT SHORTWAVE CURRENTLY DIGGING
SOUTH THROUGH NORTHERN ILLINOIS PIVOTS THROUGH THE REGION.
LOCALLY WE EXPECT CONVECTIVE INITIATION TO OCCUR FIRST ALONG THE
SEA BREEZE ACROSS PORTIONS OF CHARLESTON AND BERKELEY COUNTIES AS
FORECAST SOUNDING SUGGEST THE LOWEST CONVECTIVE TEMPERATURES /MID
80S/ WILL RESIDE THERE. ADDITIONAL ACTIVITY WILL GRADUALLY DEVELOP
AND/OR EXPAND INLAND THROUGH THE AFTERNOON AS SURFACE BASED INSTABILITY
POOLS AND LOW-LEVEL CONVERGENCE INCREASES. THUNDERSTORMS COULD
POTENTIALLY ORGANIZE INTO SOME SORT OF MESOSCALE CONVECTIVE SYSTEM
BY LATE AFTERNOON OR THIS EVENING BUT 0-6KM BULK SHEAR IS NOT
OVERLY IMPRESSIVE SO THE DEGREE OF CONVECTIVE ORGANIZATION WILL BE
HIGHLY DEPENDENT ON MESOSCALE CONVECTIVE BOUNDARY INTERACTIONS.
FORECAST SOUNDING ARE ONLY WEAKLY TO MODESTLY UNSTABLE GIVEN POOR
MID-LEVEL LAPSE RATES AND WARM H5 TEMPERATURES BUT THERMAL AND
MOISTURE PROFILES DO EXHIBIT A PSEUDO INVERTED-V CONFIGURATION
WITH WINDEX VALUES APPROACHING 50 KT. THIS SUGGESTS STRONGER
THUNDERSTORMS WHICH DEVELOP ALONG OUTFLOW COLLISIONS COULD PRODUCE
LOCALIZED DAMAGING WINDS WITH THE POTENTIAL FOR MARGINALLY SEVERE
HAIL. WILL CONTINUE TO MENTION ISOLATED SEVERE THUNDERSTORMS IN
THE HAZARDOUS WEATHER OUTLOOK. WILL ALSO BUMP POPS UP TO 50
PERCENT ACROSS INLAND AREAS AND KEEP POPS AT THE BEACHES AROUND 20
PERCENT.
CONVECTIVE DEBRIS CLOUDINESS LEFT OVER FROM YESTERDAY/S THUNDERSTORMS
IS QUICKLY THINNING THIS MORNING AND EXPECT ALL AREAS TO START OUT
WITH A FAIR AMOUNT OF SUN. MOSTLY SUNNY SKIES SHOULD BECOME MOSTLY
CLOUDY BY EARLY AFTERNOON AS A THICK CUMULUS FIELD FORMS AND
CIRRUS BLOW-OFF FROM UPSTREAM CONVECTION OVERSPREADS THE REGION.
HIGHS WILL BE TEMPERED BY THE CLOUD COVER...RANGING FROM THE LOWER
90S INLAND TO THE MID 80S CLOSER TO THE COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
SHOWER AND THUNDERSTORM COVERAGE THIS EVENING WILL BE DEPENDENT
ON THE DEGREE OF CONVECTIVE ORGANIZATION THAT CAN OCCUR THIS
AFTERNOON. WILL KEEP 50 PERCENT POPS GOING THROUGH LATE EVENING
AWAY FROM THE COAST WITH POPS TRENDING INTO THE SLIGHT CHANCE
CATEGORY ACROSS THE COASTAL WATERS. POPS MAY NEED TO BE INCREASED
INTO THE LIKELY CATEGORY LATER TODAY SHOULD A COLD BECOME
ESTABLISHED AND THE ACTIVITY BECOMES ORGANIZED. WILL KEEP AT LEAST
A SLIGHT CHANCE OF RAIN GOING AFTER MIDNIGHT AS A DECAYING FRONTAL
BOUNDARY LINKS UP WITH THE LEE-SIDE TROUGH AND MEANDERS TOWARDS
THE COAST. LOWS TONIGHT WILL BE IN THE LOWER 70S...EXCEPT MID 70S
NEAR THE COAST.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
A MEAN UPPER LEVEL TROF WILL PERSIST FROM EASTERN
CANADA SOUTHWARD THROUGH THE EASTERN PORTION OF THE COUNTY FROM
THURSDAY THROUGH TUESDAY WHILE MEAN UPPER LEVEL RIDGING PERSISTS
ACROSS THE ROCKIES. AT THE SURFACE...A LEE SIDE TROF TO THE
NORTHWEST OF OUR COUNTY WARNING AREA WILL PERSIST FOR MUCH OF THE
TIME.
THERE ARE SIGNIFICANT DIFFERENCES ON THE HANDLING OF A WEAK COLD
FRONT ON THURSDAY. THE NAM BRINGS THE FRONT THROUGH MUCH OF OUR
FORECAST AREA ON THURSDAY BEFORE IT GETS HUNG UP NEAR THE COAST BY
LATE IN THE DAY. THE GFS STALLS THE FRONT OUT FROM CENTRAL NORTH
CAROLINA TO CENTRAL GEORGIA THURSDAY BEFORE QUICKLY LIFTING IT BACK
NORTH. RECENT TRENDS OF THE GFS HAVE BEEN TO STALL THE FRONT OUT A
LITTLE FARTHER NORTH. ECMWF SOLUTION IS VERY SIMILAR TO THAT OF THE
GFS.FEELING IS THAT GFS/ECMWF HAS A BETTER HANDLE ON THE FRONTAL
POSITION AND MOVEMENT AS IT IS QUITE DIFFICULT TO GET A FRONT
THROUGH HERE DURING THE PEAK OF SUMMER. IN ADDITION...FEEL THAT GFS
HAS A BETTER HANDLE ON THE MOISTURE FIELDS AND A THREAT FOR
PRECIPITATION THURSDAY AND FRIDAY AFTERNOON/EVENING AS IT APPEARS
THAT THE NAM DRIES THINGS OUT TOO MUCH. AS A RESULT...GENERALLY
FOLLOWED THE GFS/MAV GUIDANCE FAIRLY CLOSELY THROUGH THE PERIOD.
EXPECT THE SEA BREEZE TO BE ACTIVE ON MOST DAYS AND GENERALLY HAVE
POPS NOT TOO FAR FROM THE CLIMATOLOGICAL NORM. THINK THE STRONG AREA
OF LOW PRESSURE FORECAST BY 00Z GFS TO MOVE THROUGH THE CAROLINAS ON
TUESDAY SEEMS TO BE OVERDONE.
AFTERNOON HEAT INDICES SHOULD BE NEAR 100 AWAY FROM THE COAST ON
THURSDAY AND THEN RISE A LITTLE EACH DAY AS TEMPERATURES AND
ESPECIALLY DEWPOINT TEMPERATURES SLOWLY TREND UPWARDS. FROM SUNDAY
THROUGH TUESDAY...HEAT INDICES IS SOME LOCATIONS ARE FORECAST TO
EXCEED 105 DEGREES AS DEWPOINTS IN THE MID TO PERHAPS EVEN UPPER 70S
WILL BE COMMON.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
KCHS - LIGHT FOG/HAZE WILL BURN OFF BY 12Z. CUMULUS WILL DEVELOP BY
LATE MORNING AND COULD BECOME RATHER EXTENSIVE AFTER 16Z. STILL
LOOKING FOR ISOLATED SHOWERS AND TSTMS TO FIRE ALONG THE SEA
BREEZE JUST NORTH OF THE AIRPORT BY 16Z. TOUGH CALL ON WHETHER
THIS ACTIVITY COULD DIRECTLY IMPACT THE TERMINAL SO A MENTION OF
CB/S WILL BE MAINTAINED. WILL HAVE TO CAREFULLY WATCH TO SEE IF
ANY ACTIVITY THAT FIRES OVER THE MIDLANDS MAKES A RUN FOR THE
COAST.
KSAV - CONVECTIVE DEBRIS HIGH CLOUDINESS IS HOLDING FIRM AND MAY
TAKE ANOTHER HOUR TO TWO BEFORE BREAKING. SCATTERED SHOWERS AND
THUNDERSTORMS WILL LIKELY FIRE AHEAD OF THE SEA BREEZE THIS
AFTERNOON. THE LATEST SHORT TERM GUIDANCE SUGGESTS TSTM COVERAGE
MAY BE GREATEST NEAR THE TERMINAL BETWEEN 21-24Z SO A TEMPO GROUP
FOR TSRA WILL BE INCLUDED WITH THE 12Z TAF SET. ADJUSTMENTS MAY
BE NEEDED THROUGH THE DAY ONCE MORE DEFINITIVE CONVECTIVE TRENDS
ARE ESTABLISHED.
EXTENDED AVIATION OUTLOOK...A CHANCE OF MVFR VSBYS EACH MORNING
DUE TO HIGH LOW LEVEL MOISTURE AND LIGHT WINDS...OTHERWISE VFR
CONDITIONS EXPECTED OUTSIDE OF MAINLY AFTERNOON/EVENING CONVECTION.
&&
.MARINE...
A SOUTHERLY WIND REGIME WILL PERSIST THROUGH TONIGHT AS A DECAYING
FRONTAL BOUNDARY APPROACHES FROM THE NORTHWEST. WINDS WILL REMAIN
LESS THAN 15 KNOTS WITH SEAS 4 FT OR LESS.
THE PERIOD FROM THURSDAY THROUGH SUNDAY WILL BE QUITE TRANQUIL
WITH A RELATIVELY WEAK PRESSURE GRADIENT RESULTING SOUTH TO
SOUTHWESTERLY WINDS OF 15 KNOTS OR LESS. SEAS SHOULD MAINLY BE
FROM 2 TO 3 FEET...WITH SOME 4 FOOT SEAS POSSIBLE MAINLY IN AMZ350
THIS WEEKEND.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
ST
000
FXUS62 KCAE 231103
AFDCAE
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE COLUMBIA SC
705 AM EDT WED JUL 23 2008
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION LATE TODAY...BRINGING WITH
IT ANOTHER CHANCE FOR PRECIPITATION WEDNESDAY AFTERNOON INTO
WEDNESDAY NIGHT. HIGH PRESSURE WILL BUILD INTO THE AREA THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MOSTLY CLEAR SKIES EXPECTED.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
WATER VAPOR AND MODELS SHOW VIGOROUS SHORT WAVE MOVING SOUTHEAST
INTO THE TN VALLEY. A SECOND REINFORCING SHORTWAVE IS DRIVING
SOUTH INTOT HE OHIO VALLEY AND WILL CONBINE WITH THE OTHER OVER
THE CAROLINAS AND VIRGINIA. FAIR TO GOOD UPPER LEVEL DYNAMICS AND
DEEP MOISTURE WILL LIKELY TRIGGER THE DEVELOPMENT OF A LINE OF
CONVECTION JUST AHEAD OF THE COLD FRONT BY LATE AFTERNOON. SPC HAS
SC IN A SLIGHT RISK FOR SEVERE STORMS. THE NAM AND LOCAL WRF
MODELS HAVE THE FRONT REACHING THE COAST BY THURSDAY MORNING WITH
HIGH PRESSURE BUILDING INTO THE AREA ON THURSDAY.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL BE OVER THE AREA FRIDAY BUT MOISTURE WILL
RETURN OVER THE WEEKEND AND INTO NEXT WEEK. MODELS KEEP A WEAK
TROF OVER THE AREA THROUGH THE EXTENDED PERIOD WITH A DECENT
CHANGE OF PRECIP MONDAY AND TUESDAY AS ANOTHER FRONT APPROACHES.
TEMPS WILL BE CLOSE TO NORMAL.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
MOSTLY CLEAR SKIES THIS MORNING. FRONTAL BOUNDARY WILL BE MOVING
INTO THE AREA DURING THE AFTERNOON AND EXPECT SHRA/TSRA TO DEVELOP
IN THE EARLY AFETRNOON AND CONTINUE INTO THE EVENING HOURS. WILL
HANDLE WITH CB CLOUD GROUP IN THE TAFS.
EXTENDED OUTLOOK...NO SIGNIFICANT IMPACTS TO AVIATION EXPECTED.
$$
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
SYNOPSIS...02
NEAR TERM...02
SHORT TERM...02
LONG TERM...02
AVIATION...31
000
FXUS62 KFFC 230943
AFDFFC
AREA FORECAST DISCUSSION...UPDATED FOR AVIATION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
540 AM EDT WED JUL 23 2008
.SHORT TERM /TODAY THROUGH FRIDAY/...
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
CURRENT SATELLITE LOOP SHOWS LARGE MOISTURE PLUMB EXTENDING FROM THE
NEW ENGLAND STATES DOWN TO HURRICANE DOLLY JUST OFF THE SOUTHERN TX
COAST. THERE IS ALSO A SHORTWAVE LOCATED ALONG THE AL/MS/TN BORDERS
MOVING SE. THIS WAVE IS EXPECTED TO CONTINUE MOVING SE AS IT IS
BEING PUSHED BY THE MAIN FRONT NOW EXTENDING FROM SOUTHERN OHIO TO
NEBRASKA. THIS SHORTWAVE WILL BRING ANOTHER ROUND OF AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS TO GEORGIA TODAY. EXPECT
THUNDERSTORM ACTIVITY TO DEVELOP MAINLY ACROSS CENTRAL AND SOUTHERN
SECTIONS BUT THERE WILL BE SOME SCATTERED STORMS NORTH. THIS LOOKS
TO BE ANOTHER ISOLATED SEVERE DAY SIMILAR TO YESTERDAY WITH STRONG
GUSTY WINDS...FREQUENT LIGHTNING...AND LARGE HAIL. THE MAIN COLD
FRONT WILL MOVE SOUTHWARD TODAY AND MOVE INTO N GA BY 06Z THU. THIS
FRONT IS VERY WELL ORGANIZED FOR THIS TIME OF YEAR SO IT SHOULD
SWEEP THROUGH THE AREA BEFORE STALLING SOMEWHERE ACROSS S GA/N FL
THU EVENING. HIGH PRESSURE BUILD IN BEHIND THE FRONT FRI BUT IT WILL
BE VERY WEAK AS ANOTHER SHORTWAVE MOVES IN TO N GA FRI NIGHT. WENT
VERY CLOSE TO MOS GUIDANCE WITH TEMPS IN THE SHORT TERM AS IT LOOKS
LIKE THEY HAVE PICKED UP ON THE EXPECTED CLOUD COVER OVER THE STATE
TODAY AND THE FRONT SWEEPING THROUGH FOR THU.
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
PATTERN LOOKS TO REMAIN CONSISTENT THROUGH THE EXTENDED PERIOD. THE
MODELS SHOWS A FRONT STALLING ACROSS GA SAT AND THEN ANOTHER ONE
MOVES INTO THE AREA TUE. COMBINE THIS WITH ACTIVE NW FLOW ALOFT AND
WILL KEEP A CHANCE OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY THROUGH THE EXTENDED. NORTHWEST FLOW WILL
KEEP TEMPERATURES NEAR SEASONAL NORMS AS WELL.
01
&&
.AVIATION...
MIX OF MVFR/VFR VISIBILITIES AT THE LOCAL TERMINALS EARLY THIS
MORNING WITH MOST SITES IN THE 5-7SM RANGE. MAY SEE THESE DIP A BIT
LOWER UNTIL SHORTLY AFTER SUNRISE...THOUGH ITS LOOKING INCREASINGLY
LIKELY ATL WILL REMAIN VFR 6-7SM WITH MANY OTHER SITES HITTING 3-5SM
BRIEFLY EARLY THIS MORNING. THUNDERSTORMS SHOULD REDEVELOP EARLIER
THAN YESTERDAY AND CLOSER INITIALLY TO ATL/AHN AS SFC TROUGH IS JUST
NW OF THE INTERSTATE 85 CORRIDOR FROM THE CAROLINAS INTO N GA...WITH
INITIAL THUNDER AROUND ATL BETWEEN 16-18Z. ACTIVITY EXPECTED TO WIND
DOWN EARLIEST NORTH...BUT REMAINING NEAR TO THE SOUTH OF ATL THROUGH
MUCH OF THE EVENING. WINDS SHOULD BE FROM THE WEST AND LIGHT (~10KT
OR LESS) THROUGH THE FORECAST PERIOD...OUTSIDE OF THUNDERSTORMS
WHICH MAY AGAIN GENERATE LOCALLY STRONG WINDS AND CIGS BELOW THE
PREVAILING CU AT 4-5KFT.
RRH
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 91 66 91 68 93 / 60 40 20 10 20
ATLANTA 88 68 90 70 89 / 60 30 20 10 20
BLAIRSVILLE 85 61 89 62 89 / 60 30 10 10 20
CARTERSVILLE 89 64 88 65 91 / 60 30 10 10 20
COLUMBUS 89 72 92 71 94 / 70 40 20 10 20
GAINESVILLE 89 67 89 69 90 / 60 40 10 10 20
MACON 92 71 93 71 95 / 60 40 20 10 20
ROME 88 66 91 67 94 / 60 30 10 10 20
PEACHTREE CITY 88 65 90 66 90 / 60 30 20 10 20
VIDALIA 92 72 92 71 94 / 60 50 20 20 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
000
FXUS62 KFFC 230755
AFDFFC
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PEACHTREE CITY GA
355 AM EDT WED JUL 23 2008
.SHORT TERM /TODAY THROUGH FRIDAY/...
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
CURRENT SATELLITE LOOP SHOWS LARGE MOISTURE PLUMB EXTENDING FROM THE
NEW ENGLAND STATES DOWN TO HURRICANE DOLLY JUST OFF THE SOUTHERN TX
COAST. THERE IS ALSO A SHORTWAVE LOCATED ALONG THE AL/MS/TN BORDERS
MOVING SE. THIS WAVE IS EXPECTED TO CONTINUE MOVING SE AS IT IS
BEING PUSHED BY THE MAIN FRONT NOW EXTENDING FROM SOUTHERN OHIO TO
NEBRASKA. THIS SHORTWAVE WILL BRING ANOTHER ROUND OF AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS TO GEORGIA TODAY. EXPECT
THUNDERSTORM ACTIVITY TO DEVELOP MAINLY ACROSS CENTRAL AND SOUTHERN
SECTIONS BUT THERE WILL BE SOME SCATTERED STORMS NORTH. THIS LOOKS
TO BE ANOTHER ISOLATED SEVERE DAY SIMILAR TO YESTERDAY WITH STRONG
GUSTY WINDS...FREQUENT LIGHTNING...AND LARGE HAIL. THE MAIN COLD
FRONT WILL MOVE SOUTHWARD TODAY AND MOVE INTO N GA BY 06Z THU. THIS
FRONT IS VERY WELL ORGANIZED FOR THIS TIME OF YEAR SO IT SHOULD
SWEEP THROUGH THE AREA BEFORE STALLING SOMEWHERE ACROSS S GA/N FL
THU EVENING. HIGH PRESSURE BUILD IN BEHIND THE FRONT FRI BUT IT WILL
BE VERY WEAK AS ANOTHER SHORTWAVE MOVES IN TO N GA FRI NIGHT. WENT
VERY CLOSE TO MOS GUIDANCE WITH TEMPS IN THE SHORT TERM AS IT LOOKS
LIKE THEY HAVE PICKED UP ON THE EXPECTED CLOUD COVER OVER THE STATE
TODAY AND THE FRONT SWEEPING THROUGH FOR THU.
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
PATTERN LOOKS TO REMAIN CONSISTENT THROUGH THE EXTENDED PERIOD. THE
MODELS SHOWS A FRONT STALLING ACROSS GA SAT AND THEN ANOTHER ONE
MOVES INTO THE AREA TUE. COMBINE THIS WITH ACTIVE NW FLOW ALOFT AND
WILL KEEP A CHANCE OF AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS EACH DAY THROUGH THE EXTENDED. NORTHWEST FLOW WILL
KEEP TEMPERATURES NEAR SEASONAL NORMS AS WELL.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 91 66 91 68 93 / 60 40 20 10 20
ATLANTA 88 68 90 70 89 / 60 30 20 10 20
BLAIRSVILLE 85 61 89 62 89 / 60 30 10 10 20
CARTERSVILLE 89 64 88 65 91 / 60 30 10 10 20
COLUMBUS 89 72 92 71 94 / 70 40 20 10 20
GAINESVILLE 89 67 89 69 90 / 60 40 10 10 20
MACON 92 71 93 71 95 / 60 40 20 10 20
ROME 88 66 91 67 94 / 60 30 10 10 20
PEACHTREE CITY 88 65 90 66 90 / 60 30 20 10 20
VIDALIA 92 72 92 71 94 / 60 50 20 20 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
000
FXUS62 KCHS 230727
AFDCHS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
327 AM EDT WED JUL 23 2008
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL PERSIST ACROSS INLAND AREAS TODAY.
A DECAYING FRONTAL BOUNDARY WILL APPROACH FROM THE NORTHWEST
TONIGHT AND STALL JUST NORTHWEST OF THE AREA THURSDAY BEFORE
DISSIPATING. ATLANTIC HIGH PRESSURE WILL REMAIN THROUGH NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
A NUMBER OF WELL DEFINED OUTFLOW BOUNDARIES CAN BE SEEN ACROSS THE
SOUTH CAROLINA UPSTATE...MIDLANDS AND THE NORTH CAROLINA PIEDMONT
EARLY THIS MORNING. THESE BOUNDARIES ARE EMBEDDED WITHIN A BROAD
LEE-SIDE TROUGH WHICH STRETCHES FROM CENTRAL GEORGIA THROUGH THE
PIEDMONT AREAS OF NORTH AND SOUTH CAROLINAS. ALL OF THESE BOUNDARIES
WILL SERVE AS THE FOCI FOR SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ACROSS MUCH OF THE SOUTHEAST U.S. THIS AFTERNOON AND
EVENING AS THE TAIL END OF A POTENT SHORTWAVE CURRENTLY DIGGING
SOUTH THROUGH NORTHERN ILLINOIS PIVOTS THROUGH THE REGION.
LOCALLY WE EXPECT CONVECTIVE INITIATION TO OCCUR FIRST ALONG THE
SEA BREEZE ACROSS PORTIONS OF CHARLESTON AND BERKELEY COUNTIES AS
FORECAST SOUNDING SUGGEST THE LOWEST CONVECTIVE TEMPERATURES /MID
80S/ WILL RESIDE THERE. ADDITIONAL ACTIVITY WILL GRADUALLY DEVELOP
AND/OR EXPAND INLAND THROUGH THE AFTERNOON AS SURFACE BASED INSTABILITY
POOLS AND LOW-LEVEL CONVERGENCE INCREASES. THUNDERSTORMS COULD
POTENTIALLY ORGANIZE INTO SOME SORT OF MESOSCALE CONVECTIVE SYSTEM
BY LATE AFTERNOON OR THIS EVENING BUT 0-6KM BULK SHEAR IS NOT
OVERLY IMPRESSIVE SO THE DEGREE OF CONVECTIVE ORGANIZATION WILL BE
HIGHLY DEPENDENT ON MESOSCALE CONVECTIVE BOUNDARY INTERACTIONS.
FORECAST SOUNDING ARE ONLY WEAKLY TO MODESTLY UNSTABLE GIVEN POOR
MID-LEVEL LAPSE RATES AND WARM H5 TEMPERATURES BUT THERMAL AND
MOISTURE PROFILES DO EXHIBIT A PSEUDO INVERTED-V CONFIGURATION
WITH WINDEX VALUES APPROACHING 50 KT. THIS SUGGESTS STRONGER
THUNDERSTORMS WHICH DEVELOP ALONG OUTFLOW COLLISIONS COULD PRODUCE
LOCALIZED DAMAGING WINDS WITH THE POTENTIAL FOR MARGINALLY SEVERE
HAIL. WILL CONTINUE TO MENTION ISOLATED SEVERE THUNDERSTORMS IN
THE HAZARDOUS WEATHER OUTLOOK. WILL ALSO BUMP POPS UP TO 50
PERCENT ACROSS INLAND AREAS AND KEEP POPS AT THE BEACHES AROUND 20
PERCENT.
CONVECTIVE DEBRIS CLOUDINESS LEFT OVER FROM YESTERDAY/S THUNDERSTORMS
IS QUICKLY THINNING THIS MORNING AND EXPECT ALL AREAS TO START OUT
WITH A FAIR AMOUNT OF SUN. MOSTLY SUNNY SKIES SHOULD BECOME MOSTLY
CLOUDY BY EARLY AFTERNOON AS A THICK CUMULUS FIELD FORMS AND
CIRRUS BLOW-OFF FROM UPSTREAM CONVECTION OVERSPREADS THE REGION.
HIGHS WILL BE TEMPERED BY THE CLOUD COVER...RANGING FROM THE LOWER
90S INLAND TO THE MID 80S CLOSER TO THE COAST.
&&
.SHORT TERM /TONIGHT/...
SHOWER AND THUNDERSTORM COVERAGE THIS EVENING WILL BE DEPENDENT
ON THE DEGREE OF CONVECTIVE ORGANIZATION THAT CAN OCCUR THIS
AFTERNOON. WILL KEEP 50 PERCENT POPS GOING THROUGH LATE EVENING
AWAY FROM THE COAST WITH POPS TRENDING INTO THE SLIGHT CHANCE
CATEGORY ACROSS THE COASTAL WATERS. POPS MAY NEED TO BE INCREASED
INTO THE LIKELY CATEGORY LATER TODAY SHOULD A COLD BECOME
ESTABLISHED AND THE ACTIVITY BECOMES ORGANIZED. WILL KEEP AT LEAST
A SLIGHT CHANCE OF RAIN GOING AFTER MIDNIGHT AS A DECAYING FRONTAL
BOUNDARY LINKS UP WITH THE LEE-SIDE TROUGH AND MEANDERS TOWARDS
THE COAST. LOWS TONIGHT WILL BE IN THE LOWER 70S...EXCEPT MID 70S
NEAR THE COAST.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
A MEAN UPPER LEVEL TROF WILL PERSIST FROM EASTERN
CANADA SOUTHWARD THROUGH THE EASTERN PORTION OF THE COUNTY FROM
THURSDAY THROUGH TUESDAY WHILE MEAN UPPER LEVEL RIDGING PERSISTS
ACROSS THE ROCKIES. AT THE SURFACE...A LEE SIDE TROF TO THE
NORTHWEST OF OUR COUNTY WARNING AREA WILL PERSIST FOR MUCH OF THE
TIME.
THERE ARE SIGNIFICANT DIFFERENCES ON THE HANDLING OF A WEAK COLD
FRONT ON THURSDAY. THE NAM BRINGS THE FRONT THROUGH MUCH OF OUR
FORECAST AREA ON THURSDAY BEFORE IT GETS HUNG UP NEAR THE COAST BY
LATE IN THE DAY. THE GFS STALLS THE FRONT OUT FROM CENTRAL NORTH
CAROLINA TO CENTRAL GEORGIA THURSDAY BEFORE QUICKLY LIFTING IT BACK
NORTH. RECENT TRENDS OF THE GFS HAVE BEEN TO STALL THE FRONT OUT A
LITTLE FARTHER NORTH. ECMWF SOLUTION IS VERY SIMILAR TO THAT OF THE
GFS.FEELING IS THAT GFS/ECMWF HAS A BETTER HANDLE ON THE FRONTAL
POSITION AND MOVEMENT AS IT IS QUITE DIFFICULT TO GET A FRONT
THROUGH HERE DURING THE PEAK OF SUMMER. IN ADDITION...FEEL THAT GFS
HAS A BETTER HANDLE ON THE MOISTURE FIELDS AND A THREAT FOR
PRECIPITATION THURSDAY AND FRIDAY AFTERNOON/EVENING AS IT APPEARS
THAT THE NAM DRIES THINGS OUT TOO MUCH. AS A RESULT...GENERALLY
FOLLOWED THE GFS/MAV GUIDANCE FAIRLY CLOSELY THROUGH THE PERIOD.
EXPECT THE SEA BREEZE TO BE ACTIVE ON MOST DAYS AND GENERALLY HAVE
POPS NOT TOO FAR FROM THE CLIMATOLOGICAL NORM. THINK THE STRONG AREA
OF LOW PRESSURE FORECAST BY 00Z GFS TO MOVE THROUGH THE CAROLINAS ON
TUESDAY SEEMS TO BE OVERDONE.
AFTERNOON HEAT INDICES SHOULD BE NEAR 100 AWAY FROM THE COAST ON
THURSDAY AND THEN RISE A LITTLE EACH DAY AS TEMPERATURES AND
ESPECIALLY DEWPOINT TEMPERATURES SLOWLY TREND UPWARDS. FROM SUNDAY
THROUGH TUESDAY...HEAT INDICES IS SOME LOCATIONS ARE FORECAST TO
EXCEED 105 DEGREES AS DEWPOINTS IN THE MID TO PERHAPS EVEN UPPER 70S
WILL BE COMMON.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
KCHS - WE ARE CAREFULLY MONITORING VISIBILITY TRENDS EARLY THIS
MORNING. DEWPOINTS HAVE POOLED INTO THE MID 70S WITH FAIRLY LIGHT
WINDS. IR SATELLITE IMAGERY SUGGESTS SKIES WILL REMAIN CLEAR WITH
THINNING CONVECTIVE DEBRIS HIGH CLOUDINES | 
