[top]
000
FXUS64 KJAN 151957
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
257 PM CDT WED OCT 15 2008
.SHORT TERM...WELL THINGS WILL BEGIN TO CHANGE TONIGHT AS RAIN
RE-ENTERS THE CWA. A COLD FRONT WILL MOVE TWRDS THE AREA TONIGHT AND
SLOWLY WORK ITS WAY THROUGH THE AREA TOMORROW AND FRI BEFORE FINALLY
GETTING SOUTH OF THE REGION BY FRI NIGHT. THIS COLD FRONT WILL BRING
WITH IT A DECENT CHANCE OF RAIN AND THEN COOLER TEMPS BEHIND IT.
TONIGHT THE ATMOSPHERE WILL START TO SLOWLY MOISTEN UP. HIGH
PRESSURE AT THE SFC WILL STILL BE THE DOMINATE FEATURE ACROSS THE
SERN CONUS BUT WITH THE CENTER OF THE HIGH SO FAR TO THE EAST
SOUTHERLY WINDS WILL CAUSE LL MOISTURE TO MOVE BACK INTO THE AREA. IN
THE MID LEVELS...THE RIDGE OVER THE SERN CONUS WILL SHIFT SLIGHTLY
SOUTH AND THIS WILL CAUSE IT TO LOSE ITS GRIP ON OUR AREA ALLOWING
DEEP MOISTURE TO PUSH IN. THE COMBINATION OF THESE SHOULD ALLOW PWS
TO GET ATA 2" BY TOMORROW MORNING AND FOR MID OCTOBER THAT ISN`T TOO
SHABBY(ABOUT 125% ABV NORMAL). AT THE SAME TIME THE COLD FRONT WILL
BE APPROACHING THE AREA. SHRA COULD BEGIN AS EARLY AS LATE THIS
EVENING FOR THE NWRN FRINGES OF THE CWA. IN THE MID LEVELS THERE
WILL BE A S/W MOVING THROUGH THE WRLY FLOW BUT THE BULK OF THIS
SUPPORT WILL BE TO OUR NORTH. THAT SAID...HEIGHTS WILL BE LOWERING
THROUGH THE DAY OVER THE ARKLAMISS. COMBINE THAT WITH THE COLD FRONT
AND HIGH MOISTURE CONTENT OF THE ATMOSPHERE AND THERE SHOULD BE NO
PROBLEM GETTING WIDESPREAD SHRA EARLY TOMORROW(BEGINNING IN THE
NW)...PERSISTING THROUGH THE DAY AND CONTINUING INTO THE
NIGHT(SOUTHERN SECTIONS). AS FOR THUNDER...I AM NOT EXPECTING AN
AWFUL LOT OF IT. THE ATMOSPHERE WILL BE ALMOST COMPLETELY SATURATED
KEEPING LAPSE RATES RELATIVELY SHALLOW. INSTABILITY AS A WHOLE WILL
NOT BE VERY IMPRESSIVE SO I AM ONLY EXPECTING ISOLATED TSRA. THE
BEST CHANCE FOR TSRA WILL BE ACROSS THE NWRN PORTIONS OF THE CWA
CLOSER TO THE SUPPORT FROM THE PASSING S/W. THIS WILL ALSO LEAD TO
THE POSSIBILITY OF MODERATE TO HEAVY RAIN AT TIMES IN THAT AREA.
WITH PWS EXPECTED TO BE SO HIGH SHRA AND TSRA WILL BE VERY EFFICIENT
AND THERE IS A GOOD CHANCE THAT SOME ISOLATED AREAS ACROSS THE
NORTHWEST COULD SEE UP TO 2" OF RAIN.
TOMORROW NIGHT...THROUGH FRI AND INTO FRI NIGHT...THE COLD FRONT
WILL CONTINUE TO SLOWLY PUSH TO THE SE. WITH NO REAL GOOD PUSH FROM
A S/W OR TROUGH UNTIL LATE FRI THE FRONT SHOULD LAG ACROSS THE SOUTH
FOR ABOUT 18-24HRS. DURING THAT TIME THE POSSIBILITY FOR SCT SHRA
WILL CONTINUE ACROSS THE SRN 3RD/HALF OF THE CWA WELL INTO FRI. BY
LATE FRI AFTN/EARLY EVN THE COLD FRONT SHOULD GET A GOOD PUSH AND
MOVE OUT OF THE AREA HOPEFULLY BRINGING AN END TO THE RAIN. COOLER
AND DRIER AIR WILL BE MOVING IN BEHIND IT WITH HIGHS ON FRI ONLY
EXPECTED IN THE UPPER 60S TO LOWER 70S. AS FOR LOWS THEY WILL BE A
GOOD BIT COOLER FRI AND SAT MORNING WITH THE POSSIBILITY OF SEEING
QUITE A FEW LOCATIONS ACROSS THE NORTH DIP INTO THE UPPER 40S SAT
MORNING. THE BIGGEST CONCERN SAT MORNING WILL BE WINDS. SFC WINDS
NEVER COMPLETELY DECOUPLE AND WINDS AT H952 WILL REMAIN IN THE 15 TO
20KT RANGE AND THIS WILL HURT RADIATIONAL COOLING. THAT SAID MUCH
DRIER AIR WILL HAVE ALREADY MOVED INTO THE AREA AND IF WINDS BECOME
LIGHTER THAN EXPECTED THEN LOOK FOR A GOOD PORTION OF THE ARKLAMISS
TO SEE LOWS RANGE FROM THE MID 40S TO NEAR 50 SAT MORNING.
.LONG TERM...AS FOR THE FORECAST PAST FRI NIGHT...NO MAJOR CHANGES
WERE MADE AT THIS TIME SO I WILL JUST APPEND PORTIONS OF THE PREVIOUS
LONG TERM DISCUSSION TO ACCOUNT FOR THE FORECAST FROM SATURDAY THROUGH
EARLY NEXT WEEK. /CAB/
BY SATURDAY EVENING THE UPPER TROUGH WILL PUSH OFF THE EAST COAST AS
A RIDGE STRETCHES AND THEN FLATTENS FROM THE EASTERN ROCKIES INTO
THE MISSISSIPPI VALLEY. THE FLAT RIDGE PATTERN WILL REMAIN IN PLACE INTO
EARLY NEXT WEEK BEFORE WE SEE A TROUGH DROP OUT OF WRN CANADA THEN
CLOSING OFF AS IT MOVES PAST THE ROCKIES EARLY WEDNESDAY. THE
EUROPEAN MODEL WAS FARTHER WEST WITH THE CLOSED UPPER LOW OVER THE
SOUTHWEST CONUS. AS FOR THIS WEEKEND HIGH PRESSURE WILL PROVIDE DRY
WEATHER ALONG WITH COOLER NIGHTS AND MILD DAYS. NORMALS FOR THIS TIME
OF THE YEAR AT MOST SITES ARE IN THE LOWER 50S FOR LOWS AND MID 70S
FOR HIGHS.
AS FAR AS TEMPS ARE CONCERNED WITH THIS TYPE OF PATTERN...IT LOOKS LIKE
COOLER AIR WILL COME DOWN NORTHWEST FLOW INTO THE REGION FOR THE
WEEKEND INTO EARLY NEXT WEEK. MEX...MEN ENSEMBLES AND MOS GUIDANCE
CONTINUE ACKNOWLEDGE THE COOL AIRMASS WITH COOLER TEMPS BUT I MADE A
FEW CUTS BELOW GUIDANCE ON LOWS FOR SATURDAY NIGHT TOWARD THE
LOWER-MIDDLE SIDE OF THE MEAN ENSEMBLE VALUES. WENT CLOSER TO THE MEX
VALUES FOR HIGHS. SO BASICALLY I AM LOOKING FOR MIDDLE TO UPPER 40S
FOR SATURDAY NIGHT...WHICH WILL BE THE COOLEST NIGHT. TEMPS WILL
GRADUALLY RISE TO THE UPPER 40S TO LOWER 50S FOR SUNDAY NIGHT...THEN
WILL RISE INTO THE LOWER TO MIDDLE 50S BY MONDAY AND TUESDAY NIGHTS. AS
FOR HIGHS LOOK FOR LOWER TO MIDDLE 70S FOR SATURDAY...MIDDLE TO UPPER
70S FOR SUNDAY...THEN MIDDLE TO 70S TO AROUND 80 FOR MONDAY AND MID
TO UPPER 70S FOR TUESDAY. /17/
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL THIS EVENING...WITH THE POSSIBLE
EXCEPTION AT GLH WHERE BROKEN MVFR CEILINGS COULD DEVELOP AS
INCREASING SHOWER ACTIVITY WEST OF THE MS RIVER APPROACHES. A COLD
FRONT WILL APPROACH GLH/GWO AFTER 09Z WHEN CONDITIONS SHOULD
DETERIORATE DUE TO LOWER CEILINGS AND INCREASING RAIN/TSTM ACTIVITY.
WIDESPREAD IFR CONDITIONS WILL BE POSSIBLE THERE THROUGH THURSDAY
MORNING...POSSIBLY DEVELOPING AT GTR AS WELL. AT JAN/MEI/HBG...
FOG/STRATUS COULD DEVELOP AND PRODUCE IFR CONDITIONS DURING THE
PERIOD FROM 05-14Z THURSDAY MORNING...WITH LIFR CONDITIONS POSSIBLE
AT HBG. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 64 76 58 68 / 37 68 48 34
MERIDIAN 60 81 58 70 / 18 48 43 39
VICKSBURG 64 75 57 68 / 59 71 43 25
HATTIESBURG 61 83 62 72 / 8 36 41 50
NATCHEZ 66 78 58 68 / 45 69 56 41
GREENVILLE 63 70 54 73 / 78 70 19 9
GREENWOOD 62 71 54 72 / 69 72 22 12
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
CAB/EC
000
FXUS64 KJAN 151610
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
1110 AM CDT WED OCT 15 2008
.DISCUSSION...ANOTHER QUIET DAY FOR THE MOST PART. THE SURFACE HIGH
WILL CONTINUE TO DOMINATE OVER THE SERN CONUS BUT IT WILL ALSO
CONTINUE TO SLOWLY DRIFT EAST. THIS WILL ALLOW MOISTURE TO BEGIN TO
RETURN AND SHOULD SET THE STAGE FROM SOME RAIN MAYBE AS EARLY AS
THIS EVENING(MORE LIKELY TOMORROW THOUGH) ACROSS THE FAR NW. AS FOR
THE FORECAST IT LOOKS ON TARGET AND NO ADJUSTMENTS APPEAR TO BE
NEEDED. /CAB/
&&
.PREV DISCUSSION...
SHORT TERM...TODAY THROUGH THURSDAY...LARGE CENTER OF HIGH PRESSURE
SURFACE AND ALOFT CENTERED OVER THE SOUTHEAST STATES THIS MORNING
WILL SLOWLY SHIFT SOUTH INTO THE NORTHERN GULF BY FRIDAY. A
WEAKENING UPPER TROUGH WILL RIDE UP OVER THE HIGH AND TRY TO BRING A
COLD FRONT INTO OUR CWFA. THIS COLD FRONT WILL HAVE A HARD TIME
DROPPING INTO OUR CWFA UNTIL FRIDAY WHEN A STRONGER SHORTWAVE TROUGH
AND SURFACE HIGH MOVE ACROSS THE REGION. A MUCH DRIER AIRMASS WITH
PWS BELOW AN INCH AND SURFACE DEW POINTS IN THE MID 50S RESIDES
UNDER THE CENTER OF HIGH PRESSURE WHILE MID 60 DEW POINTS AND PWS
NEAR TWO INCHES ARE EXPECTED TO POOL ALONG AND AHEAD OF THE COLD
FRONT. THIS WILL LEAD TO INCREASING RAIN CHANCES IN THE SHORT TERM
OVER OUR WESTERN ZONES WHILE OUR EAST AND SOUTHEAST ZONES SEE LITTLE
CHANCE OF RAIN. FOR TODAY...WL SEE A FEW MORE CLOUDS IN THE WEST
THAN IN THE EAST AND A LATE AFTERNOON SHOWER...BUT HIGH PRESSURE
WILL KEEP MOST OF OUR CWFA DRY AND WARMER THAN NORMAL. AFTERNOON
HIGHS SHOULD TOP OUT IN THE MID 80S. TONIGHT AS HIGH PRESSURE SHIFTS
TO THE GULF COAST...THE COLD FRONT WILL APPROACH OF DELTA REGION
AFTER MIDNIGHT. THIS WILL BRING AND INCREASE IN CLOUD COVER AND RAIN
INTO OUR WESTERN ZONES BY MORNING. OVERNIGHT LOW TEMPERATURES MAY
DIP INTO THE UPPER 50S EAST BUT REMAIN IN THE MID 60S WEST. HAVE
GONE A COUPLE DEGREES WARMER THAN GUIDANCE IN THE WEST. THURSDAY THE
COLD FRONT WILL BE OVER OUR DELTA REGION WHILE HIGH PRESSURE STILL
HANGS ON OVER OUR SOUTHEAST. AS STORMS TRAIN ACROSS SOME OF THE SAME
AREAS A COUPLE OF INCHES OF RAIN LOOK TO BE POSSIBLE BY THE END OF
THE DAY IN OUR NORTHWEST. CLOUDS AND RAIN WILL LIMIT INSOLATION AND
RESULT IN COOLER TEMPERATURES IN OUR NORTHWEST THURSDAY. ENSEMBLE
GUIDANCE STANDARD DEVIATIONS OF 2 FOR MAX TEMPS WERE NOTED OVER THE
DELTA AND LATEST MAV GUIDANCE WAS AMONG THE LOWEST ENSEMBLE MEMBERS.
HAVE OPTED TO RAISE MAX TEMPS A COUPLE OF DEGREES TOWARD MAV
ENSEMBLE MEANS WHICH WERE CLOSER TO NGM GUIDANCE ;). HIGHS THURSDAY
ARE EXPECTED TO RANGE FROM THE LOWER 70S NORTHWEST TO THE MID 80S
SOUTHEAST. /22/
LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY...MEDIUM RANGE MODELS
CONTINUE TO SHOWS A FAST MOVING FALL LIKE HIGHLY CHANGEABLE UPPER
PATTERN FOR THE UPCOMING PERIOD. THE MEDIUM RANGE MODELS AND
ENSEMBLES CONTINUE TO SHOWS ZONAL PATTERN WHICH TRANSITIONS TO A
RIDGE-TROUGH UPPER PATTERN AS WE GO TOWARD THE WEEKEND. THE UPPER
TROUGH DEVELOPS OVER THE EASTERN US FOR THIS WEEKEND...WHILE AN
AMPLIFIED RIDGE SETTLES IN THE ROCKIES AND PLAINS. BY SATURDAY
EVENING THE UPPER TROUGH WILL PUSH OFF THE EAST COAST AS THE UPPER
RIDGE STRETCHES AND FLATTENS FROM THE EASTERN ROCKIES TO THE
MISSISSIPPI VALLEY. THE FLAT RIDGE PATTERN WILL EXTEND INTO EARLY
NEXT WEEK. THE FLAT UPPER RIDGE WILL TRANSITION AS A CLOSED UPPER
LOW COMES TOWARD THE MIDDLE MISSISSIPPI VALLEY BY WEDNESDAY. THE
EUROPEAN MODEL WAS FARTHER WEST WITH THE CLOSED UPPER LOW OVER THE
SOUTHWEST CONUS.
THE MEDIUM RANGE MODELS CONTINUE TO SHOW A STRONG SHORT WAVE COMING
DOWN IN NORTHWEST FLOW...WHICH WILL TRANSITION THE UPPER PATTERN TO
RIDGE-TROUGH FORMATION BY THIS WEEKEND. THIS WILL HELP SEND COOL
HIGH PRESSURE INTO THE REGION IN THE WAKE OF A SECOND STRONGER COLD
FRONT FOR FRIDAY NIGHT INTO SATURDAY. THE STRONGER COLD FRONT WILL
COME THROUGH THE REGION ON FRIDAY...WHICH WILL PICK UP THE FIRST
FRONT AND SWEEP ACROSS THE REGION BY FRIDAY AFTERNOON. LOOKING AT
AREA SOUNDINGS AND INSTABILITY. PRECIPITABLE WATER WILL BE AROUND 2
INCHES...WHICH MAY SPELL SOME LOCAL DOWNPOURS. AS FAR AS INSTABILITY
NO SIGNIFICANT CAPES...LIFTED INDEXES OR SHOWALTER INDEX WILL BE
WITH THIS SYSTEM. AS FAR JET ENERGY IS CONCERN THERE WILL BE ENOUGH
ENERGY TO ENCOURAGE SOME LOCAL DOWN POURS. THE MAIN JET ENERGY WILL
COME INTO THE REGION AFTER THE COLD FRONT FOR FRIDAY NIGHT. SO WITH
THIS IN MIND WILL REMOVE GENERAL THUNDER FROM THE GRIDS...BUT MAY
LEAVE ISOLATED THUNDER IN THE AFTERNOON IN THE SOUTH FOR FRIDAY. FOR
THIS WEEKEND HIGH PRESSURE WILL PROVIDE DRY WEATHER WITH COOL NIGHTS
AND MILD DAYS.
AS A RESULT OUR BEST RAIN CHANCES FOR THIS WEEK WILL BE ON THURSDAY
NIGHT THROUGH FRIDAY FOLLOWED BY COOLER THAN NORMAL TEMPERATURES AND
DRIER WEATHER FOR THE WEEKEND. SURFACE HIGH PRESSURE MOVED INTO THE
REGION FOR THIS WEEKEND.
NORMALS FOR THIS TIME OF THE YEAR AT MOST SITES ARE IN THE LOWER 50S
FOR LOWS AND MID 70S FOR HIGHS.
AS FAR AS TEMPS ARE CONCERN WITH THIS TYPE OF PATTERN LOOKS LIKE SOME
COOL AIR WILL COME DOWN NORTHWEST FLOW INTO THE REGION FOR THE
WEEKEND INTO EARLY NEXT WEEK. MEX...MEN ENSEMBLES AND MOS GUIDANCE
CONTINUE ACKNOWLEDGE THE COOL AIRMASS WITH LOWER PROG TEMPS. BUT
MADE A FEW DEGREE CUTS BELOW GUIDANCE ON NIGHTLY LOWS FOR FRIDAY AND
SATURDAY NIGHTS TOWARD THE LOWER TO MIDDLE MEAN ENSEMBLE NUMBERS.
WENT CLOSE TO MEX AND MOS GUIDANCE ON DAILY HIGHS. MADE SLIGHT
ADJUSTMENTS TO MOS GUIDANCE ON NIGHTLY LOWS FOR THURSDAY NIGHT AS
WELL AS SUNDAY THROUGH TUESDAY NIGHTS.
DAILY LOWS DURING THE FIRST FRONTAL PASSAGE WILL BE MIDDLE 50S TO
LOWER 60S FOR THURSDAY NIGHT...THEN AFTER THE FRONTAL PASSAGE UPPER
40S TO LOWER 50S FOR FRIDAY NIGHT. MIDDLE TO UPPER 40S FOR SATURDAY
NIGHT...WHICH WILL BE THE COOLEST NIGHT. TEMPS WILL GRADUALLY RISE
TO THE UPPER 40S TO LOWER 50S FOR SUNDAY NIGHT...THEN WILL RISE
TO THE LOWER TO MIDDLE 50S BY MONDAY AND TUESDAY NIGHTS.
FOR DAILY HIGHS WILL BE THE LOWER 70S FOR FRIDAY...THEN LOWER 70S TO
MIDDLE 70S FOR SATURDAY...MIDDLE TO UPPER 70S FOR SUNDAY...THEN
MIDDLE TO 70S TO AROUND 80 FOR MONDAY AND MID TO UPPER 70S FOR
TUESDAY.
/17/
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL THIS AFTERNOON. BROKEN MVFR
CEILINGS COULD DEVELOP BY LATE AFTERNOON AND EVENING OVER THE GLH
AREA AS INCREASING SHOWER ACTIVITY WEST OF THE MS RIVER APPROACHES.
AS THE COLD FRONT APPROACHES GLH/GWO AFTER 08Z...CONDITIONS WILL
DETERIORATE DUE TO LOWER CEILINGS AND INCREASING RAIN/TSTM ACTIVITY.
WIDESPREAD IFR CONDITIONS WILL BE POSSIBLE THERE THROUGH THURSDAY
MORNING...POSSIBLY DEVELOPING AT GTR AS WELL. AT JAN/MEI/HBG...
FOG/STRATUS COULD DEVELOP AND PRODUCE IFR CONDITIONS BETWEEN 08-14Z
THURSDAY MORNING. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 87 63 78 59 / 4 34 49 50
MERIDIAN 86 59 81 58 / 2 14 29 46
VICKSBURG 87 64 76 57 / 15 52 64 49
HATTIESBURG 87 61 85 61 / 2 11 17 34
NATCHEZ 85 65 78 58 / 20 44 54 46
GREENVILLE 88 64 73 54 / 14 67 74 45
GREENWOOD 87 62 75 55 / 5 52 71 52
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
CAB
000
FXUS64 KJAN 150823
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
317 AM CDT WED OCT 15 2008
.SHORT TERM...TODAY THROUGH THURSDAY...LARGE CENTER OF HIGH PRESSURE
SURFACE AND ALOFT CENTERED OVER THE SOUTHEAST STATES THIS MORNING
WILL SLOWLY SHIFT SOUTH INTO THE NORTHERN GULF BY FRIDAY. A
WEAKENING UPPER TROUGH WILL RIDE UP OVER THE HIGH AND TRY TO BRING A
COLD FRONT INTO OUR CWFA. THIS COLD FRONT WILL HAVE A HARD TIME
DROPPING INTO OUR CWFA UNTIL FRIDAY WHEN A STRONGER SHORTWAVE TROUGH
AND SURFACE HIGH MOVE ACROSS THE REGION. A MUCH DRIER AIRMASS WITH
PWS BELOW AN INCH AND SURFACE DEW POINTS IN THE MID 50S RESIDES
UNDER THE CENTER OF HIGH PRESSURE WHILE MID 60 DEW POINTS AND PWS
NEAR TWO INCHES ARE EXPECTED TO POOL ALONG AND AHEAD OF THE COLD
FRONT. THIS WILL LEAD TO INCREASING RAIN CHANCES IN THE SHORT TERM
OVER OUR WESTERN ZONES WHILE OUR EAST AND SOUTHEAST ZONES SEE LITTLE
CHANCE OF RAIN. FOR TODAY...WL SEE A FEW MORE CLOUDS IN THE WEST
THAN IN THE EAST AND A LATE AFTERNOON SHOWER...BUT HIGH PRESSURE
WILL KEEP MOST OF OUR CWFA DRY AND WARMER THAN NORMAL. AFTERNOON
HIGHS SHOULD TOP OUT IN THE MID 80S. TONIGHT AS HIGH PRESSURE SHIFTS
TO THE GULF COAST...THE COLD FRONT WILL APPROACH OF DELTA REGION
AFTER MIDNIGHT. THIS WILL BRING AND INCREASE IN CLOUD COVER AND RAIN
INTO OUR WESTERN ZONES BY MORNING. OVERNIGHT LOW TEMPERATURES MAY
DIP INTO THE UPPER 50S EAST BUT REMAIN IN THE MID 60S WEST. HAVE
GONE A COUPLE DEGREES WARMER THAN GUIDANCE IN THE WEST. THURSDAY THE
COLD FRONT WILL BE OVER OUR DELTA REGION WHILE HIGH PRESSURE STILL
HANGS ON OVER OUR SOUTHEAST. AS STORMS TRAIN ACROSS SOME OF THE SAME
AREAS A COUPLE OF INCHES OF RAIN LOOK TO BE POSSIBLE BY THE END OF
THE DAY IN OUR NORTHWEST. CLOUDS AND RAIN WILL LIMIT INSOLATION AND
RESULT IN COOLER TEMPERATURES IN OUR NORTHWEST THURSDAY. ENSEMBLE
GUIDANCE STANDARD DEVIATIONS OF 2 FOR MAX TEMPS WERE NOTED OVER THE
DELTA AND LATEST MAV GUIDANCE WAS AMONG THE LOWEST ENSEMBLE MEMBERS.
HAVE OPTED TO RAISE MAX TEMPS A COUPLE OF DEGREES TOWARD MAV
ENSEMBLE MEANS WHICH WERE CLOSER TO NGM GUIDANCE ;). HIGHS THURSDAY
ARE EXPECTED TO RANGE FROM THE LOWER 70S NORTHWEST TO THE MID 80S
SOUTHEAST. /22/
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY...MEDIUM RANGE MODELS
CONTINUE TO SHOWS A FAST MOVING FALL LIKE HIGHLY CHANGEABLE UPPER
PATTERN FOR THE UPCOMING PERIOD. THE MEDIUM RANGE MODELS AND
ENSEMBLES CONTINUE TO SHOWS ZONAL PATTERN WHICH TRANSITIONS TO A
RIDGE-TROUGH UPPER PATTERN AS WE GO TOWARD THE WEEKEND. THE UPPER
TROUGH DEVELOPS OVER THE EASTERN US FOR THIS WEEKEND...WHILE AN
AMPLIFIED RIDGE SETTLES IN THE ROCKIES AND PLAINS. BY SATURDAY
EVENING THE UPPER TROUGH WILL PUSH OFF THE EAST COAST AS THE UPPER
RIDGE STRETCHES AND FLATTENS FROM THE EASTERN ROCKIES TO THE
MISSISSIPPI VALLEY. THE FLAT RIDGE PATTERN WILL EXTEND INTO EARLY
NEXT WEEK. THE FLAT UPPER RIDGE WILL TRANSITION AS A CLOSED UPPER
LOW COMES TOWARD THE MIDDLE MISSISSIPPI VALLEY BY WEDNESDAY. THE
EUROPEAN MODEL WAS FARTHER WEST WITH THE CLOSED UPPER LOW OVER THE
SOUTHWEST CONUS.
THE MEDIUM RANGE MODELS CONTINUE TO SHOW A STRONG SHORT WAVE COMING
DOWN IN NORTHWEST FLOW...WHICH WILL TRANSITION THE UPPER PATTERN TO
RIDGE-TROUGH FORMATION BY THIS WEEKEND. THIS WILL HELP SEND COOL
HIGH PRESSURE INTO THE REGION IN THE WAKE OF A SECOND STRONGER COLD
FRONT FOR FRIDAY NIGHT INTO SATURDAY. THE STRONGER COLD FRONT WILL
COME THROUGH THE REGION ON FRIDAY...WHICH WILL PICK UP THE FIRST
FRONT AND SWEEP ACROSS THE REGION BY FRIDAY AFTERNOON. LOOKING AT
AREA SOUNDINGS AND INSTABILITY. PRECIPITABLE WATER WILL BE AROUND 2
INCHES...WHICH MAY SPELL SOME LOCAL DOWNPOURS. AS FAR AS INSTABILITY
NO SIGNIFICANT CAPES...LIFTED INDEXES OR SHOWALTER INDEX WILL BE
WITH THIS SYSTEM. AS FAR JET ENERGY IS CONCERN THERE WILL BE ENOUGH
ENERGY TO ENCOURAGE SOME LOCAL DOWN POURS. THE MAIN JET ENERGY WILL
COME INTO THE REGION AFTER THE COLD FRONT FOR FRIDAY NIGHT. SO WITH
THIS IN MIND WILL REMOVE GENERAL THUNDER FROM THE GRIDS...BUT MAY
LEAVE ISOLATED THUNDER IN THE AFTERNOON IN THE SOUTH FOR FRIDAY. FOR
THIS WEEKEND HIGH PRESSURE WILL PROVIDE DRY WEATHER WITH COOL NIGHTS
AND MILD DAYS.
AS A RESULT OUR BEST RAIN CHANCES FOR THIS WEEK WILL BE ON THURSDAY
NIGHT THROUGH FRIDAY FOLLOWED BY COOLER THAN NORMAL TEMPERATURES AND
DRIER WEATHER FOR THE WEEKEND. SURFACE HIGH PRESSURE MOVED INTO THE
REGION FOR THIS WEEKEND.
NORMALS FOR THIS TIME OF THE YEAR AT MOST SITES ARE IN THE LOWER 50S
FOR LOWS AND MID 70S FOR HIGHS.
AS FAR AS TEMPS ARE CONCERN WITH THIS TYPE OF PATTERN LOOKS LIKE SOME
COOL AIR WILL COME DOWN NORTHWEST FLOW INTO THE REGION FOR THE
WEEKEND INTO EARLY NEXT WEEK. MEX...MEN ENSEMBLES AND MOS GUIDANCE
CONTINUE ACKNOWLEDGE THE COOL AIRMASS WITH LOWER PROG TEMPS. BUT
MADE A FEW DEGREE CUTS BELOW GUIDANCE ON NIGHTLY LOWS FOR FRIDAY AND
SATURDAY NIGHTS TOWARD THE LOWER TO MIDDLE MEAN ENSEMBLE NUMBERS.
WENT CLOSE TO MEX AND MOS GUIDANCE ON DAILY HIGHS. MADE SLIGHT
ADJUSTMENTS TO MOS GUIDANCE ON NIGHTLY LOWS FOR THURSDAY NIGHT AS
WELL AS SUNDAY THROUGH TUESDAY NIGHTS.
DAILY LOWS DURING THE FIRST FRONTAL PASSAGE WILL BE MIDDLE 50S TO
LOWER 60S FOR THURSDAY NIGHT...THEN AFTER THE FRONTAL PASSAGE UPPER
40S TO LOWER 50S FOR FRIDAY NIGHT. MIDDLE TO UPPER 40S FOR SATURDAY
NIGHT...WHICH WILL BE THE COOLEST NIGHT. TEMPS WILL GRADUALLY RISE
TO THE UPPER 40S TO LOWER 50S FOR SUNDAY NIGHT...THEN WILL RISE
TO THE LOWER TO MIDDLE 50S BY MONDAY AND TUESDAY NIGHTS.
FOR DAILY HIGHS WILL BE THE LOWER 70S FOR FRIDAY...THEN LOWER 70S TO
MIDDLE 70S FOR SATURDAY...MIDDLE TO UPPER 70S FOR SUNDAY...THEN
MIDDLE TO 70S TO AROUND 80 FOR MONDAY AND MID TO UPPER 70S FOR
TUESDAY.
/17/
&&
.AVIATION...UNDER HIGH PRESSURE THE WINDS HAVE DECOUPLED AT MOST
SITES AND PATCHY IFR CONDITIONS WERE REPORTED AT GTR AND HBG. EXPECT
PREVAILING MVFR VISIBILITIES THIS MORNING AT MOST SITES WITH
OCCASIONAL IFR/LIFR CONDITIONS IN THE EAST. THE FOG/STRATUS SHOULD
DISSIPATE BY 14Z AND VFR CONDITIONS WILL PREVAIL OVER MOST OF THE
AREA TODAY. ISOLATED SHOWERS AND MAYBE A THUNDERSTORM WILL BE
POSSIBLE IN THE WEST LATE THIS AFTERNOON AS MOISTURE INCREASES THERE
AHEAD OF AN APPROACHING COLD FRONT. THIS FRONT WILL MOVE INTO THE
NORTHWEST THURSDAY AND RESULT IN GREATER SHOWER AND THUNDERSTORM
COVERAGE THERE. HIGH PRESSURE WILL LIMIT CONVECTION IN THE SOUTHEAST
THROUGH THURSDAY./22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 87 63 78 59 / 4 34 49 50
MERIDIAN 86 59 81 58 / 2 14 29 46
VICKSBURG 87 64 76 57 / 15 52 64 49
HATTIESBURG 87 61 85 61 / 2 11 17 34
NATCHEZ 85 65 78 58 / 20 44 54 46
GREENVILLE 88 64 73 54 / 14 67 74 45
GREENWOOD 87 62 75 55 / 5 52 71 52
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
SHORT TERM/AVIATION: 22
LONG TERM: 17
000
FXUS64 KJAN 150215
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
915 PM CDT TUE OCT 14 2008
.UPDATE...TWEAKED THE HOURLY VALUES TO ACCOUNT FOR THE SLOWER
COOLING AND CLEARING SKIES. MUCH OF THE CWA IS CLEAR AT THIS
POINT...BUT SOUNDING SUGGEST CLOUDS MAY REDEVELOP BRIEFLY OVERNIGHT.
MAINTAIN PARTLY CLOUDY/MOSTLY CLEAR IN MOST LOCATIONS. OVERALL THE
CURRENT FORECAST WAS GOOD. NO NEED TO SEND UPDATED ZONES.
&&
.AVIATION...WILL MAINTAIN VFR CONDITIONS FOR MOST OF THE PERIOD. WILL
MAINTAIN MVFR CONDITIONS FOR PATCHY FOG AND POSSIBLE STRATUS IN THE
9-13Z TIME PERIOD. OTHERWISE...CEILINGS SHOULD REMAIN ABOVE 3KFT
THROUGH AT 3Z THURSDAY. CLOUDS WILL RETURN IN THE WEST...GENERALLY
FOR GLH/TVR/HEZ...AFTER 00Z. AGAIN CEILING SHOULD REMAIN ABOVE
3KFT...SO PREVAILING VFR CONDITIONS LOOK GOOD THROUGH THE FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 63 86 63 81 / 2 6 22 59
MERIDIAN 59 86 59 84 / 2 4 10 32
VICKSBURG 64 87 65 80 / 3 15 40 67
HATTIESBURG 63 87 60 85 / 3 5 8 21
NATCHEZ 66 86 66 80 / 10 22 29 55
GREENVILLE 64 89 64 75 / 5 10 50 76
GREENWOOD 62 88 63 77 / 2 4 36 77
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
7
000
FXUS64 KJAN 142105
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
348 PM CDT TUE OCT 14 2008
.SHORT TERM...UPPER RIDGING HOLDING IN THE SHORT TERM BUT WILL SEE
AN INCREASING CHANCE OF RAIN AND THUNDERSTORMS FROM THE WEST LATE
WEDNESDAY AS A COLD FRONT MOVES THIS WAY. THE FRONT WILL MOVE INTO
WRN ZONES EARLY THURSDAY...EXITING SERN ZONES EARLY FRIDAY. THE
BOUNDARY WILL WEAKEN SLOWLY AS IT DRAGS ACROSS THE REGION AS THE
ASSOCIATED SURFACE LOW PULLS AWAY TO THE NE. A VERY MOIST AIR MASS
WILL BE IN PLACE AHEAD OF THIS SYSTEM WITH A POCKET OF PRECIPITABLE
WATER VALUES WELL ABOVE 2 INCHES AHEAD OF THE BOUNDARY. THE AIR MASS
WILL REMAIN RELATIVELY STABLE SO FRONTAL FORCING AND UPPER DYNAMICS
WILL DETERMINE RAINFALL INTENSITY FOR THE AREA. HEALTHY UPPER LEVEL
DIVERGENCE WILL DEVELOP AS A JET MAX TRACKS N OF THE REGION. FRONTAL
FORCING WILL BE SUFFICIENT FOR WIDESPREAD CONVECTION WHEN THE
BOUNDARY MOVES THROUGH BUT THE STRONGER FORCING WILL REMAIN N OF THE
REGION.
TEMPERATURES WILL BE CHALLENGING WITH THIS SYSTEM CONSIDERING THE
TIMING TO MODERATE FROM UNSEASONABLY WARM TEMPS EARLY THIS WEEK TO
COOLER TEMPS WITH DEVELOPING PRECIP AND ASSOCIATED CLOUD COVER THAT
WILL PRECEDE STRONG COLD AIR ADVECTION BEHIND THE FRONT. MID 50S LOW
TEMPS ADVERTISED BY MOS FOR ECENTRAL ZONES WED NIGHT LOOK TOO COOL
IN WAA AHEAD OF THE FRONT...ESPECIALLY WITH THE POSSIBILITY OF
MORNING STRATUS AHEAD OF THE BOUNDARY. TRENDED LOWER ON THU HIGHS
PER LATEST MOS BUT NOT TO SUCH A SEVERE DEGREE AS MOS DOES WITH ITS
HIGHS NEAR 70 IN THE DELTA. THIS WILL BEAR WATCHING IN CASE THE
COLDER AIR BEGINS SEEPING SWD FASTER BUT LOOKS TOO COOL FOR NOW.
.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...THE MEDIUM RANGE
MODELS CONTINUE TO SHOWS A FAST MOVING FALL LIKE HIGHLY CHANGEABLE
UPPER PATTERN FOR THE UPCOMING PERIOD. THE MEDIUM RANGE MODELS
CONTINUE TO SHOW A HIGHLY AMPLIFIED RIDGE-TROUGH PATTERN WHICH
TRANSITIONS TO A ZONAL PATTERN BY THURSDAY. AS WE GO TOWARD THE
WEEKEND THE UPPER PATTERN TRANSITIONS TO A RIDGE-TROUGH AMPLIFIED
PATTERN. THE UPPER TROUGH DEVELOPS OVER THE EASTERN US FOR THIS
WEEKEND...WHILE AN AMPLIFIED RIDGE SETTLES IN THE ROCKIES AND
PLAINS. BY SUNDAY THE UPPER TROUGH WILL PUSH OFF THE EAST COAST AS
THE UPPER RIDGE STRETCHES AND FLATTENS FROM THE EASTERN ROCKIES TO
THE MISSISSIPPI VALLEY. THE FLAT RIDGE PATTERN WILL EXTEND INTO
EARLY NEXT WEEK.
ON THE SURFACE THE MEDIUM RANGE MODELS SHOWS THAT A COLD FRONT WILL
PUSH INTO THE REGION ON THURSDAY THEN STALL OVER THE REGION WITH A
GOOD CHANCE OF RAIN ACROSS THE ARKLAMISS. ON THIS LATEST RUN IT
MATCHES THE GOOD GENERAL RAIN COVERAGE OF THE EUROPEAN MODEL THROUGH
FRIDAY. PRECIPITABLE WATER WILL INCREASE TO AROUND 2 INCHES...WHICH
MAY SPELL SOME LOCAL DOWNPOURS. A STRONGER COLD FRONT WILL PUSH INTO
THE REGION ON FRIDAY AND COMBINE WITH THE FIRST FRONT...TAKING IT TO
THE COAST BY FRIDAY EVENING. BREEZY CONDITIONS WILL PREVAIL ACROSS
THE REGION ON SATURDAY BEHIND THE FRONT. THE STRONGER FRONT WILL BE
ASSOCIATED WITH A STRONG SHORTWAVE TROUGH...WHICH WILL HELP TO
TRANSITION THE PATTERN TO A RIDGE-TROUGH FORMATION BY THE WEEKEND.
AS A RESULT OUR BEST RAIN CHANCES FOR THIS WEEK WILL BE ON WEDNESDAY
NIGHT THROUGH FRIDAY FOLLOWED BY COOLER THAN NORMAL TEMPERATURES AND
DRIER WEATHER FOR THE WEEKEND. SURFACE HIGH PRESSURE MOVED INTO THE
REGION FOR THIS WEEKEND. THE GFS MODEL SHOWED STRONGER HIGH PRESSURE
1032 THEN THE EUROPEAN 1028.
NORMALS FOR THIS TIME OF THE YEAR AT MOST SITES ARE IN THE LOWER 50S
FOR LOWS AND MID 70S FOR HIGHS.
AS FAR AS TEMPS ARE CONCERN WITH THIS TYPE OF PATTERN LOOKS LIKE SOME
COOL AIR WILL COME DOWN NORTHWEST FLOW INTO THE REGION FOR THE
WEEKEND INTO EARLY NEXT WEEK. MEX AND MOS GUIDANCE SEEM TO
ACKNOWLEDGE THE COOL AIRMASS WITH LOWER PROG TEMPS. BUT MADE A FEW
DEGREE CUTS BELOW GUIDANCE ON NIGHTLY LOWS TOWARD THE MIDDLE MEAN
ENSEMBLE NUMBERS. WENT CLOSE TO MAV AND MOS GUIDANCE ON DAILY HIGHS.
FOR FRIDAY MADE SLIGHT ADJUSTMENTS TO MOS AND MEX GUIDANCE.
DAILY LOWS AFTER THE FRONTAL PASSAGE WILL BE IN THE MIDDLE 40S TO
LOWER 50S FOR FRIDAY NIGHT...THEN LOWER TO MIDDLE 40S FOR SATURDAY
NIGHT...THEN UPPER 40S TO LOWER 50S FOR EARLY NEXT WEEK.
FOR DAILY HIGHS WILL BE FROM THE MID TO UPPER 70S FOR FRIDAY...THEN
NEAR 70 TO LOWER 70S FOR SATURDAY...LOWER TO MIDDLE 70S FOR
SUNDAY...THEN MIDDLE TO UPPER 70S FOR MONDAY AND TUESDAY.
/17/
&&
.AVIATION...SCATTERED TO BROKEN STRATOCUMULUS WILL CONTINUE TO
RESULT IN AREAS OF MVFR RESTRICTIONS THIS AFTERNOON BUT THESE CLOUDS
SHOULD DISSIPATE WITH LOSS OF HEATING TOWARD SUNSET. VFR CONDITIONS
WILL PREVAIL THIS EVNG WITH MVFR RESTRICTIONS DEVELOPING LATE
TONIGHT AND EARLY WEDNESDAY IN AREAS OF FOG...ESPECIALLY FROM
09-14Z. VFR CONDITIONS WILL PREVAIL FOR MOST PART ONCE FOG BURNS OFF
WEDNESDAY MORNING. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 63 86 63 81 / 2 6 22 59
MERIDIAN 59 86 59 84 / 2 4 10 32
VICKSBURG 64 87 65 80 / 3 15 40 67
HATTIESBURG 63 87 60 85 / 3 5 8 21
NATCHEZ 66 86 66 80 / 10 22 29 55
GREENVILLE 64 89 64 75 / 5 10 50 76
GREENWOOD 62 88 63 77 / 2 4 36 77
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
03/17/EC
000
FXUS64 KJAN 141602
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
1100 AM CDT TUE OCT 14 2008
.DISCUSSION...FORECAST GENERALLY ON TRACK. HOWEVER...PERSISTENT AREA
OF LOW CLOUDS OVER SWRN ZONES WILL HAMPER LATE MORNING/EARLY
AFTERNOON HEATING FOR COOLER THAT EXPECTED HIGHS FOR THAT AREA SO
HAVE ADJUSTED TEMPS/CLOUD COVER ACCORDINGLY.
&&
.PREV DISCUSSION...330 AM CDT TUE OCT 14 2008 TODAY THROUGH
WEDNESDAY...HIGH PRESSURE SURFACE AND ALOFT CENTERED OVER THE
SOUTHERN APPALACHIANS WILL SHIFT SOUTH THROUGH THE PERIOD AND INTO
THE NORTHERN GULF BY THURSDAY. THIS WILL RESULT IN WARMER THAN
NORMAL TEMPERATURES AND DRY WEATHER FOR MUCH OF THE ARKLAMISS. A
COLD FRONT WILL APPROACH THE WESTERN PORTIONS OF THE AREA BY LATE
WEDNESDAY AFTERNOON AND BRING A CHANCE OF RAIN...MAINLY WEST OF THE
MISSISSIPPI RIVER. DESPITE THE LACK OF CLOUD COVER DURING THE EARLY
A.M. HOURS SURFACE TEMPERATURES WERE RUNNING IN THE UPPER 60S TO
LOWER 70S WHICH IS NEARLY 15 DEGREES ABOVE NORMAL FOR THIS TIME OF
YEAR. THE 925MB AND 850MB TEMPS OF 19-20C AND 14.5C TODAY SHOULD
SUPPORT AFTERNOON HIGHS IN THE LOW TO MID 80S. THE 925MB AND 850MB
TEMPS OF 20-21C AND 15C WEDNESDAY WILL SUPPORT AFTERNOON HIGHS A
COUPLE DEGREES WARMER THAN TODAY IN THE MID 80S. MAV GUIDANCE HIGHS
WERE CLOSE AT MOST SITES BUT SEVERAL DEGREES TOO HIGH OVER THE
DELTA. BEING THE HIGHEST ENSEMBLE MEMBER AT MOST SITES IN THE DELTA
AS WELL...HAVE CUT MAX TEMPS CLOSER TO ENSEMBLE MEAN TODAY AND
WEDNESDAY. THE 00Z TUE JAN SOUNDING HAD A PW OF AN INCH AND A HALF.
AS HIGH PRESSURE STRENGTHENS OVER OUR REGION TODAY AND
WEDNESDAY...DRIER AIR WITH PWS BELOW ONE INCH WILL FILTER IN FROM
THE EAST. THIS WILL OCCUR AS PWS GREATER THAN AN INCH AND A HALF
POOL AHEAD OF THE THE COLD FRONTAL SYSTEM WEDNESDAY. THIS WILL
RESULT IN QUITE A MOISTURE GRADIENT OVER OUR CWFA WEDNESDAY. MOST OF
THE AREA WILL REMAIN DRY THROUGH WEDNESDAY BUT A FEW SHOWERS AND
PERHAPS A THUNDERSTORM WILL BE POSSIBLE OVER OUR WESTERN COUNTIES
AND PARISHES WEDNESDAY AFTERNOON.
/22/
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY...THE MEDIUM RANGE
MODELS CONTINUE TO SHOWS A FAST MOVING FALL LIKE HIGHLY CHANGEABLE
UPPER PATTERN FOR THE UPCOMING PERIOD. THE MEDIUM RANGE MODELS
CONTINUE TO SHOW A HIGHLY AMPLIFIED RIDGE-TROUGH PATTERN WHICH
TRANSITIONS TO A ZONAL PATTERN BY THURSDAY. AS WE GO TOWARD THE
WEEKEND THE UPPER PATTERN TRANSITIONS TO A RIDGE-TROUGH AMPLIFIED
PATTERN. THE UPPER TROUGH DEVELOPS OVER THE EASTERN US FOR THIS
WEEKEND...WHILE AN AMPLIFIED RIDGE SETTLES IN THE ROCKIES AND
PLAINS. BY SUNDAY THE UPPER TROUGH WILL PUSH OFF THE EAST COAST AS
THE UPPER RIDGE STRETCHES AND FLATTENS FROM THE EASTERN ROCKIES TO
THE MISSISSIPPI VALLEY. THE FLAT RIDGE PATTERN WILL EXTEND INTO
EARLY NEXT WEEK.
ON THE SURFACE THE MEDIUM RANGE MODELS SHOWS THAT A COLD FRONT WILL
PUSH INTO THE REGION ON THURSDAY THEN STALL OVER THE REGION WITH A
GOOD CHANCE OF RAIN ACROSS THE ARKLAMISS. ON THIS LATEST RUN IT
MATCHES THE GOOD GENERAL RAIN COVERAGE OF THE EUROPEAN MODEL THROUGH
FRIDAY. PRECIPITABLE WATER WILL INCREASE TO AROUND 2 INCHES...WHICH
MAY SPELL SOME LOCAL DOWNPOURS. A STRONGER COLD FRONT WILL PUSH INTO
THE REGION ON FRIDAY AND COMBINE WITH THE FIRST FRONT...TAKING IT TO
THE COAST BY FRIDAY EVENING. BREEZY CONDITIONS WILL PREVAIL ACROSS
THE REGION ON SATURDAY BEHIND THE FRONT. THE STRONGER FRONT WILL BE
ASSOCIATED WITH A STRONG SHORTWAVE TROUGH...WHICH WILL HELP TO
TRANSITION THE PATTERN TO A RIDGE-TROUGH FORMATION BY THE WEEKEND.
AS A RESULT OUR BEST RAIN CHANCES FOR THIS WEEK WILL BE ON WEDNESDAY
NIGHT THROUGH FRIDAY FOLLOWED BY COOLER THAN NORMAL TEMPERATURES AND
DRIER WEATHER FOR THE WEEKEND. SURFACE HIGH PRESSURE MOVED INTO THE
REGION FOR THIS WEEKEND. THE GFS MODEL SHOWED STRONGER HIGH PRESSURE
1032 THEN THE EUROPEAN 1028.
NORMALS FOR THIS TIME OF THE YEAR AT MOST SITES ARE IN THE LOWER 50S
FOR LOWS AND MID 70S FOR HIGHS.
AS FAR AS TEMPS ARE CONCERN WITH THIS TYPE OF PATTERN LOOKS LIKE SOME
COOL AIR WILL COME DOWN NORTHWEST FLOW INTO THE REGION FOR THE
WEEKEND INTO EARLY NEXT WEEK. MEX AND MOS GUIDANCE SEEM TO
ACKNOWLEDGE THE COOL AIRMASS WITH LOWER PROG TEMPS. BUT MADE A FEW
DEGREE CUTS BELOW GUIDANCE ON NIGHTLY LOWS TOWARD THE MIDDLE MEAN
ENSEMBLE NUMBERS. WENT CLOSE TO MAV AND MOS GUIDANCE ON DAILY HIGHS.
FOR WEDNESDAY NIGHT THROUGH FRIDAY MADE SLIGHT ADJUSTMENTS TO MOS AND
MEX GUIDANCE.
DAILY LOWS WILL BE MAINLY IN THE 60S FOR WEDNESDAY NIGHT...THEN
MIDDLE 50S TO LOWER 60S ON THURSDAY NIGHT...THEN AFTER THE FRONTAL
PASSAGE MIDDLE 40S TO LOWER 50S FOR FRIDAY NIGHT...THEN LOWER TO
MIDDLE 40S FOR SATURDAY NIGHT...THEN UPPER 40S TO LOWER 50S FOR
EARLY NEXT WEEK.
FOR DAILY HIGHS WILL BE FROM THE UPPER 70S TO MIDDLE 80S FOR
THURSDAY...MID TO UPPER 70S FOR FRIDAY...THEN NEAR 70 TO LOWER 70S
FOR SATURDAY...LOWER TO MIDDLE 70S FOR SUNDAY...THEN MIDDLE TO UPPER
70S FOR MONDAY AND TUESDAY.
AS FAR AS POPS WERE CONCERN WENT WITH THE WET GFS POPS FOR WEDNESDAY
NIGHT THROUGH FRIDAY WITH PRECIPITABLE WATER ABOVE 2 INCHES. THESE
POPS WERE CLOSE TO HIGH ENSEMBLE POPS. /17/
&&
.AVIATION...AREA OF IFR/MVFR STRATUS DEVELOPED EARLY THIS MORNING
AND HAS BEEN SLOWLY LIFTING AS IT GRADUALLY SHIFTS NORTHWARD
ACCORDING TO OBSERVATIONS AND SATELLITE IMAGERY. THERE MAY BE A
PERIOD OF MVFR RESTRICTIONS AT JACKSON OVER THE NEXT COUPLE OF HOURS
AS THIS CLOUD DECK ATTEMPTS TO MOVE IN...BUT CONTINUED HEATING
SHOULD CAUSE THE DECK TO LIFT FURTHER AND BREAK UP AS WE GO INTO THE
AFTERNOON. OTHERWISE...VFR CONDITIONS ARE EXPECTED PREVAIL THIS AFTN
AND EVNG WITH MVFR RESTRICTIONS DEVELOPING LATE TONIGHT AND EARLY
WEDNESDAY IN FOG. /EC/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
SHORT TERM/AVIATION: 22
LONG TERM: 17
03/EC
000
FXUS64 KJAN 140830
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
330 AM CDT TUE OCT 14 2008
.SHORT TERM...TODAY THROUGH WEDNESDAY...HIGH PRESSURE SURFACE AND
ALOFT CENTERED OVER THE SOUTHERN APPALACHIANS WILL SHIFT SOUTH
THROUGH THE PERIOD AND INTO THE NORTHERN GULF BY THURSDAY. THIS WILL
RESULT IN WARMER THAN NORMAL TEMPERATURES AND DRY WEATHER FOR MUCH
OF THE ARKLAMISS. A COLD FRONT WILL APPROACH THE WESTERN PORTIONS OF
THE AREA BY LATE WEDNESDAY AFTERNOON AND BRING A CHANCE OF
RAIN...MAINLY WEST OF THE MISSISSIPPI RIVER. CURRENT SATELLITE
IMAGERY AND SURFACE OBSERVATIONS ARE SHOWING VERY LITTLE CLOUD COVER
OVER THE CWFA. DESPITE THE LACK OF CLOUD COVER SURFACE TEMPERATURES
WERE RUNNING IN THE UPPER 60S TO LOWER 70S WHICH IS NEARLY 15
DEGREES ABOVE NORMAL FOR THIS TIME OF YEAR. THE 925MB AND 850MB
TEMPS OF 19-20C AND 14.5C TODAY SHOULD SUPPORT AFTERNOON HIGHS IN
THE LOW TO MID 80S. THE 925MB AND 850MB TEMPS OF 20-21C AND 15C
WEDNESDAY WILL SUPPORT AFTERNOON HIGHS A COUPLE DEGREES WARMER THAN
TODAY IN THE MID 80S. MAV GUIDANCE HIGHS WERE CLOSE AT MOST SITES
BUT SEVERAL DEGREES TOO HIGH OVER THE DELTA. BEING THE HIGHEST
ENSEMBLE MEMBER AT MOST SITES IN THE DELTA AS WELL...HAVE CUT MAX
TEMPS CLOSER TO ENSEMBLE MEAN TODAY AND WEDNESDAY. THE 00Z TUE JAN
SOUNDING HAD A PW OF AN INCH AND A HALF. AS HIGH PRESSURE
STRENGTHENS OVER OUR REGION TODAY AND WEDNESDAY...DRIER AIR WITH PWS
BELOW ONE INCH WILL FILTER IN FROM THE EAST. THIS WILL OCCUR AS PWS
GREATER THAN AN INCH AND A HALF POOL AHEAD OF THE THE COLD FRONTAL
SYSTEM WEDNESDAY. THIS WILL RESULT IN QUITE A MOISTURE GRADIENT OVER
OUR CWFA WEDNESDAY. MOST OF THE AREA WILL REMAIN DRY THROUGH
WEDNESDAY BUT A FEW SHOWERS AND PERHAPS A THUNDERSTORM WILL BE
POSSIBLE OVER OUR WESTERN COUNTIES AND PARISHES WEDNESDAY AFTERNOON.
/22/
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY...THE MEDIUM RANGE
MODELS CONTINUE TO SHOWS A FAST MOVING FALL LIKE HIGHLY CHANGEABLE
UPPER PATTERN FOR THE UPCOMING PERIOD. THE MEDIUM RANGE MODELS
CONTINUE TO SHOW A HIGHLY AMPLIFIED RIDGE-TROUGH PATTERN WHICH
TRANSITIONS TO A ZONAL PATTERN BY THURSDAY. AS WE GO TOWARD THE
WEEKEND THE UPPER PATTERN TRANSITIONS TO A RIDGE-TROUGH AMPLIFIED
PATTERN. THE UPPER TROUGH DEVELOPS OVER THE EASTERN US FOR THIS
WEEKEND...WHILE AN AMPLIFIED RIDGE SETTLES IN THE ROCKIES AND
PLAINS. BY SUNDAY THE UPPER TROUGH WILL PUSH OFF THE EAST COAST AS
THE UPPER RIDGE STRETCHES AND FLATTENS FROM THE EASTERN ROCKIES TO
THE MISSISSIPPI VALLEY. THE FLAT RIDGE PATTERN WILL EXTEND INTO
EARLY NEXT WEEK.
ON THE SURFACE THE MEDIUM RANGE MODELS SHOWS THAT A COLD FRONT WILL
PUSH INTO THE REGION ON THURSDAY THEN STALL OVER THE REGION WITH A
GOOD CHANCE OF RAIN ACROSS THE ARKLAMISS. ON THIS LATEST RUN IT
MATCHES THE GOOD GENERAL RAIN COVERAGE OF THE EUROPEAN MODEL THROUGH
FRIDAY. PRECIPITABLE WATER WILL INCREASE TO AROUND 2 INCHES...WHICH
MAY SPELL SOME LOCAL DOWNPOURS. A STRONGER COLD FRONT WILL PUSH INTO
THE REGION ON FRIDAY AND COMBINE WITH THE FIRST FRONT...TAKING IT TO
THE COAST BY FRIDAY EVENING. BREEZY CONDITIONS WILL PREVAIL ACROSS
THE REGION ON SATURDAY BEHIND THE FRONT. THE STRONGER FRONT WILL BE
ASSOCIATED WITH A STRONG SHORTWAVE TROUGH...WHICH WILL HELP TO
TRANSITION THE PATTERN TO A RIDGE-TROUGH FORMATION BY THE WEEKEND.
AS A RESULT OUR BEST RAIN CHANCES FOR THIS WEEK WILL BE ON WEDNESDAY
NIGHT THROUGH FRIDAY FOLLOWED BY COOLER THAN NORMAL TEMPERATURES AND
DRIER WEATHER FOR THE WEEKEND. SURFACE HIGH PRESSURE MOVED INTO THE
REGION FOR THIS WEEKEND. THE GFS MODEL SHOWED STRONGER HIGH PRESSURE
1032 THEN THE EUROPEAN 1028.
NORMALS FOR THIS TIME OF THE YEAR AT MOST SITES ARE IN THE LOWER 50S
FOR LOWS AND MID 70S FOR HIGHS.
AS FAR AS TEMPS ARE CONCERN WITH THIS TYPE OF PATTERN LOOKS LIKE SOME
COOL AIR WILL COME DOWN NORTHWEST FLOW INTO THE REGION FOR THE
WEEKEND INTO EARLY NEXT WEEK. MEX AND MOS GUIDANCE SEEM TO
ACKNOWLEDGE THE COOL AIRMASS WITH LOWER PROG TEMPS. BUT MADE A FEW
DEGREE CUTS BELOW GUIDANCE ON NIGHTLY LOWS TOWARD THE MIDDLE MEAN
ENSEMBLE NUMBERS. WENT CLOSE TO MAV AND MOS GUIDANCE ON DAILY HIGHS.
FOR WEDNESDAY NIGHT THROUGH FRIDAY MADE SLIGHT ADJUSTMENTS TO MOS AND
MEX GUIDANCE.
DAILY LOWS WILL BE MAINLY IN THE 60S FOR WEDNESDAY NIGHT...THEN
MIDDLE 50S TO LOWER 60S ON THURSDAY NIGHT...THEN AFTER THE FRONTAL
PASSAGE MIDDLE 40S TO LOWER 50S FOR FRIDAY NIGHT...THEN LOWER TO
MIDDLE 40S FOR SATURDAY NIGHT...THEN UPPER 40S TO LOWER 50S FOR
EARLY NEXT WEEK.
FOR DAILY HIGHS WILL BE FROM THE UPPER 70S TO MIDDLE 80S FOR
THURSDAY...MID TO UPPER 70S FOR FRIDAY...THEN NEAR 70 TO LOWER 70S
FOR SATURDAY...LOWER TO MIDDLE 70S FOR SUNDAY...THEN MIDDLE TO UPPER
70S FOR MONDAY AND TUESDAY.
AS FAR AS POPS WERE CONCERN WENT WITH THE WET GFS POPS FOR WEDNESDAY
NIGHT THROUGH FRIDAY WITH PRECIPITABLE WATER ABOVE 2 INCHES. THESE
POPS WERE CLOSE TO HIGH ENSEMBLE POPS. /17/
&&
.AVIATION...HIGH PRESSURE SURFACE AND ALOFT TO OUR EAST WILL
GRADUALLY BRING DRIER AIR INTO OUR AREA. VERY LITTLE CLOUD COVER WAS
BEING REPORTED THIS MORNING NOR SEEN ON SATELLITE IMAGERY. VFR
CONDITIONS WERE BEING AT ALL TAF SITES ALTHOUGH DENSE FOG WAS BEING
REPORTED AT LLQ IN SOUTHEAST ARKANSAS AND MIST AT NMM IN EAST
CENTRAL MISSISSIPPI. EXPECT MVFR VISIBILITIES TO DEVELOP AT MOST
SITES BETWEEN 10 AND 13Z THIS MORNING BUT A WIDESPREAD LAYER OF
STRATUS BELOW 3KFT IS NOT EXPECTED. VFR CONDITIONS ARE EXPECTED TO
PREVAIL AREAWIDE AFTER 13Z TODAY. /22/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 84 63 86 61 / 1 2 12 35
MERIDIAN 84 59 86 56 / 2 2 5 17
VICKSBURG 85 64 86 63 / 2 3 21 51
HATTIESBURG 84 64 87 60 / 7 3 5 10
NATCHEZ 84 66 84 63 / 5 10 29 46
GREENVILLE 84 63 86 61 / 5 5 19 53
GREENWOOD 84 61 86 61 / 1 2 9 40
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
SHORT TERM/AVIATION: 22
LONG TERM: 17
000
FXUS64 KJAN 140112
AFDJAN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSON MS
812 PM CDT MON OCT 13 2008
.UPDATE...A FEW SHOWERS CONTINUE OVER THE AREA...MUCH OF THE ACTIVITY
SHOULD END IN THE NEXT HOUR OR TWO. WILL HOLD OFF ON AN UPDATE. THERE
WERE BREAKS IN THE CLOUDS TO THE EAST...BUT MODELS CONTINUE TO
SUGGEST CEILINGS WILL RETURN...SO LEFT THE AREA PARTLY TO MOSTLY
CLOUDY THROUGH TONIGHT. DEWPOINTS WERE STILL UP...BUT DRIER AIR WAS
JUST EAST OF THE CWA. LOWER TO MID 60S LOOK GOOD FOR LOWS. MADE SOME
SMALL TWEAKS TO THE HOURLY VALUES AND SKY COVER...OTHERWISE THE
FORECAST WAS GOOD.
MODELS SEEM TO AGREE THE WEEKEND WILL BE DRY. THE LATEST GUIDANCE
CAME IN COOLER...SO TEMPERATURES WERE LOWERED SATURDAY AND SUNDAY.
WITH THE COLD FRONT EXPECTED AT THE END OF THE WEEK AND A REINFORCING
SHOT OF COOL AND DRY AIR WITH THE CANADIAN HIGH MOVING THROUGH THE
FOR THE WEEKEND...THE VALUES WERE TOO WARM. OTHERWISE...NO OTHER
CHANGES.
&&
.AVIATION...
CEILINGS WILL CONTINUE TO BOUNCE AROUND THIS EVENING. WILL LIKELY
HAVE TO MAINTAIN SCT-BKN025-030. CEILINGS WILL LIKELY RANGE FROM
015-025 IN THE 8-13Z TIME PERIOD...KEPT THE WORSENING CONDITIONS IN
THE TEMPO GROUP. PATCHY FOG HAS ALREADY DEVELOPED AT GWO...SO MAY
HAVE TO LOWER VISIBILITIES AFTER MIDNIGHT. OVERALL...LOOKING FOR
PATCHY FOG ACROSS THE AREA...GENERALLY CAUSING MVFR CONDITIONS. ADDED
TEMPORARY LIFR CONDITIONS AT MEI/HBG...WHERE SKIES HAVE CLEARED
BRIEFLY. MAY ADD TO GTR ALSO. WINDS WERE GENERALLY LIGHT OUT OF THE
SOUTHEAST AND WILL REMAIN THE SAME THROUGH THE FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 66 83 63 85 / 14 7 1 7
MERIDIAN 64 84 58 86 / 11 6 1 7
VICKSBURG 65 85 63 86 / 18 16 8 8
HATTIESBURG 66 84 61 88 / 11 6 1 7
NATCHEZ 66 84 65 86 / 21 23 10 10
GREENVILLE 66 85 64 86 / 15 22 7 9
GREENWOOD 66 84 62 86 / 14 12 2 7
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
7
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