[top]
000
FXUS66 KOTX 241131
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
430 AM PDT THU JUL 24 2008
.SYNOPSIS...
A WARMING AND DRYING TREND WILL COMMENCE TODAY AND LAST THROUGH
AND PEAK ON FRIDAY WITH ABOVE NORMAL TEMPERATURES. THIS TREND
WILL MODERATE DURING THE WEEKEND...WHICH WILL REMAIN DRY AND
SLIGHTLY WARMER THAN AVERAGE.
&&
.DISCUSSION...
TODAY AND TONIGHT...THE UPPER LEVEL WAVE WHICH BROUGHT YESTERDAY`S
THUNDERSTORM ACTIVITY TO THE NORTHERN ZONES IS CURRENTLY
SKITTERING EASTWARD INTO THE PRAIRIE PROVINCES. A BACK SIDE
VORTICITY LOBE LIES JUST NORTH OF THE IDAHO PANHANDLE AND MAY
PROVIDE ENOUGH LIFT FOR A STRAY SHOWER OR SPRINKLE OVER THE
EXTREME NORTHEAST ZONES EARLY THIS MORNING...BEFORE THE ENTIRE
SYSTEM DEPARTS AND ALLOWS A SHARP SHORT WAVE RIDGE TO BUILD BACK
OVER THE FORECAST AREA BY THIS AFTERNOON. NAM AND GFS ARE SIMILAR
AND APPEAR PLAUSIBLE AGAINST SATELLITE EXTRAPOLATION FOR THE NEXT
24 TO 36 HOURS FEATURING THIS RIDGE ALOFT AND THE RETURN OF THE
SURFACE THERMAL TROUGH BUILDING INTO THE FAR WESTERN ZONES TODAY.
THE AIR MASS WILL BE LARGELY STABILIZING UNDER THE RIDGE
ALOFT...BUT SOME REMAINING IN-SITU LOW LEVEL MOISTURE MAY GIN UP
INTO SOME FLAT CUMULUS THIS AFTERNOON OVER THE HIGHER TERRAIN OF
THE EAST BASIN AND OVER THE MOUNTAIN ZONES. OTHERWISE MOSTLY
SUNNY...LIGHT WINDS AND MAX TEMPERATURES RECOVERING FROM
YESTERDAY`S ABNORMALLY COOL READINGS TO VALUES AT OR NEAR SEASONAL
AVERAGES. TONIGHT LITTLE CHANGE IN THE DRY AND PLACID
REGIME...WITH THE SURFACE THERMAL TROUGH STRENGTHENING OVER THE
CASCADES WHICH MAY PRODUCE NEAR BREEZY EASTERLY WINDS OVER THE
PALOUSE AND THROUGH THE PURCELL TRENCH AT COEUR D`ALENE BY DAWN.
FRIDAY THROUGH SUNDAY...ONCE AGAIN ALL EYES ARE SET ON THE SYSTEM
NOW ENCROACHING ON 140W OVER THE PACIFIC...AS IT WILL LIKELY BE
THE MAIN PLAYER IN THE WEATHER THROUGH THIS PORTION OF THE
FORECAST. THE CURRENT LONGITUDINAL STRETCHING PATTERN NOTED ON
WATER VAPOR WITH THIS SYSTEM ALREADY SUGGESTS THE MID-LEVEL ENERGY
IS IN THE PROCESS OF ROUNDING THE BASE OF THE UPPER LEVEL TROUGH
OVER THE PACIFIC...AND WITH THE MID-LEVEL ENERGY GETTING
STRETCHED...THE SYSTEM HAS LIKELY ALREADY PEAKED IN INTENSITY. AS
THE STRETCHED SYSTEM GRADUALLY SHEARS OUT EASTWARD...ALL MODELS
CARRY SHORT WAVE ENERGY TOWARD THE CWA LATE FRIDAY NIGHT/EARLY
SATURDAY. AHEAD OF THIS SHORT WAVE TROUGH...WARM ADVECTION AND
RIDGING DRIVE 850 MB TEMPERATURES UP TO +24C ON THE GFS AND ECMWF
FRIDAY AFTERNOON WITH SOUNDINGS SUPPORTING A WELL MIXED ATMOSPHERE
BELOW THAT LAYER. ADDITIONALLY...GEFS MEAN 850 MB TEMPERATURES
UNDER THE PEAKING RIDGE FRIDAY AFTERNOON ARE ACTUALLY A TAD WARMER
THAN THE GFS OR ECMWF...WHICH IS VERY STRANGE GIVEN THE ALREADY
STRONG RIDGE DEPICTED ON THE GFS. THIS SUGGESTED THE ENSEMBLE
SOLUTIONS FAVOR AN EVEN STRONGER SHORT WAVE RIDGE THAN THE GFS
DEPICTS...SO HIGH TEMPERATURES HAVE BEEN BUMPED UP A DEGREE OR TWO
OVERALL FOR FRIDAY FROM THE PREVIOUS FORECAST PACKAGE.
AS THE SYSTEM PASSES FRIDAY NIGHT AND THROUGH THE DAY
SATURDAY...HEIGHTS AND LAYER TEMPERATURES FALL OFF ACCORDINGLY.
WITH MID-LEVEL COOLING AND ADDITIONAL MID-LEVEL MOISTURE INFLUX
PER THE GFS WITH FLOW TURNING MORE OFF THE PACIFIC...MID AND HIGH
BASED CLOUDS WILL LIKELY BE FAIRLY COMMON FRIDAY NIGHT
TRANSITIONING TO MORE OF AN AFTERNOON CUMULUS REGIME BY SATURDAY
AS MOISTURE ASSOCIATED WITH THE SYSTEM WANES AND AFTERNOON
INSTABILITY DOMINATES DUE TO THE COOLER AIR ALOFT MOVING IN AND
STRONGER MID-LEVEL THETA-E LAPSE RATES. THE PATTERN THAT HAS
DOMINATED THE AREA RECENTLY THEN TAKES HOLD AGAIN WITH WEAK WAVES
IN SOUTHWESTERLY FLOW ALOFT DAMPENING ANY SIGNIFICANT RIDGING OVER
THE AREA...YIELDING DRY CONDITIONS OVERALL WITH A DEARTH OF
BOUNDARY LAYER MOISTURE AND RATHER SEASONABLE TEMPERATURES THROUGH
MID-WEEK NEXT WEEK AFTER WHICH TIMES THE MODELS BEGIN TO TREND
BACK TOWARD A STRONGER FOUR CORNERS HIGH DEVELOPING AND RIDGING
DOMINATING THE AREA AGAIN BY THE END OF THE WEEK. /FRIES
&&
.AVIATION...
VALLEY FOG AND STRATUS WILL LOCALLY CREATE IFR CEILINGS AND
VISIBILITIES IN VALLEYS NORTH OF THE COLUMBIA BASIN THIS MORNING
FROM 12Z TO 16Z...THEN EVAPORATE. WITH AN UPPER LEVEL RIDGE
DEVELOPING OVER THE REGION...VFR CONDITIONS ARE EXPECTED AT ALL
LOCATIONS THROUGH 12Z FRIDAY WITH SOME VFR BROKEN CUMULUS CEILINGS
OVER MOUNTAINS THIS AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 82 57 93 63 87 60 / 0 0 0 0 0 0
COEUR D`ALENE 81 53 93 58 86 59 / 0 0 0 0 0 0
PULLMAN 81 48 92 53 86 53 / 0 0 0 0 0 0
LEWISTON 89 61 100 66 93 64 / 0 0 0 0 0 0
COLVILLE 89 50 94 54 90 54 / 10 0 0 0 0 0
SANDPOINT 80 47 90 54 84 54 / 10 0 0 0 0 10
KELLOGG 79 55 92 60 83 58 / 0 0 0 0 0 0
MOSES LAKE 87 54 97 62 91 61 / 0 0 0 0 0 0
WENATCHEE 87 60 95 65 88 64 / 0 0 0 0 0 0
OMAK 90 54 97 58 91 57 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
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000
FXUS66 KSEW 241037
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 AM PDT THU JUL 24 2008
.SYNOPSIS...AN UPPER LEVEL RIDGE WILL BUILD OVER WESTERN WASHINGTON
TODAY THEN SHIFT EAST TONIGHT AND FRIDAY. LIGHT SURFACE GRADIENTS
AND LEFT OVER LOW LEVEL MOISTURE WILL GIVE AREAS OF MORNING LOW
CLOUDS TODAY. LESS CLOUD COVER IS EXPECTED TONIGHT AND FRIDAY. A
WEAK FRONT ARRIVING EARLY SATURDAY WILL INCREASE CLOUDS OVER THE
AREA AND BRING A CHANCE OF RAIN OR DRIZZLE MAINLY TO THE COAST. A
SERIES OF WEAK UPPER LEVEL SYSTEMS MOVING THROUGH THE PACIFIC
NORTHWEST SUNDAY AND MONDAY WILL KEEP CONDITIONS ON THE CLOUDY AND
COOL SIDE INTO THE EARLY PART OF NEXT WEEK.
&&
.SHORT TERM...SATELLITE IMAGERY SHOWS STRATUS ALONG THE
COAST...ALONG THE WEST SLOPES OF THE CASCADES AND BEGINNING TO FILL
IN OVER THE INTERIOR FROM SEATTLE NORTHWARD. SURFACE GRADIENTS ARE
FLAT AND EVEN THOUGH UPPER LEVEL RIDGE BUILDING INTO THE AREA THIS
MORNING...THE RIDGE AXIS IS STILL OFFSHORE AND THE WINDS ALOFT OVER
THE AREA ARE LIGHT SO EXPECT MORE LOW CLOUDS TO FORM IN THE NEXT
COUPLE OF HOURS. WITH THE RIDGE BUILDING IN DURING THE MORNING HOURS
LOW CLOUDS WON`T LAST VERY LONG EXCEPT ALONG THE COAST WHERE
BREAKOUT WILL BE A LITTLE LATER IN THE DAY. NOT MUCH CHANGE FROM THE
PREVIOUS FORECAST WITH THE UPPER LEVEL RIDGE SHIFTING TO THE EAST
TONIGHT AND FRIDAY. SURFACE GRADIENTS FAIRLY FLAT TONIGHT INTO
FRIDAY MORNING. THIS COMBINED WITH THE RIDGING ALOFT WILL LIMIT THE
ARIEL COVERAGE OF MORNING LOW CLOUDS MAINLY TO THE COAST FRIDAY.
ONSHORE GRADIENTS PICKING UP FRIDAY AFTERNOON WITH THE WEAK SURFACE
RIDGE BUILDING ALONG THE COAST OUT AHEAD OF A WEAK FRONT BACK OUT
NEAR 130W. THE PARENT LOW FOR THE FRONT IS UP IN THE GULF OF ALASKA.
IN ADDITION THE FRONT WILL BE RUNNING INTO THE BACKSIDE OF THE
RIDGE. THESE FACTORS WILL CONTINUE TO WEAKEN THE FRONT AS IT
APPROACHES THE COAST FRIDAY NIGHT INTO SATURDAY. WITH THE ONSHORE
GRADIENTS AND PLENTY OF LOW LEVEL MOISTURE THERE COULD BE ENOUGH
LIFT TO GET SOME LIGHT RAIN OR DRIZZLE ALONG THE COAST FRIDAY NIGHT
INTO SATURDAY. FOR THE REMAINDER OF THE AREA JUST INCREASING CLOUDS
FRIDAY NIGHT WITH CLOUDY AND COOLER CONDITIONS ON SATURDAY WITH
DAYTIME HIGHS RUNNING AROUND 10 DEGREES BELOW NORMAL.
.LONG TERM...WEAK TROUGHINESS HANGING OVER THE AREA ON SUNDAY WITH
LOW LEVEL ONSHORE FLOW FOR ANOTHER CLOUDY AND COOL DAY. MODELS
SQUEEZING OUT A LITTLE BIT OF PRECIPITATION OVER THE AREA WITH THE
WEAK TROUGH BUT 500 MB HEIGHTS AREA STILL ABOVE 570 DM AND THE
ONSHORE GRADIENTS ARE NOT VERY STRONG. WILL LEAN TOWARD CLIMO AND
KEEP THE PRECIP OUT OF THE FORECAST FOR NOW. EXTENDED MODELS IN GOOD
AGREEMENT FOR THE FIRST PART OF NEXT WEEK WITH WESTERLY FLOW ALOFT
OVER THE AREA AND LOW LEVEL ONSHORE FLOW. THIS LEADS TO A MORNING
CLOUDS AFTERNOON SUNSHINE FORECAST WITH TEMPERATURES JUST A TOUCH
BELOW NORMAL FOR THE END OF JULY. FELTON
&&
.AVIATION...UPPER RIDGE OVER WESTERN WASHINGTON TODAY MOVING OVER
EASTERN WA TONIGHT. AREAS OF LOW LEVEL MOISTURE WESTERN WASHINGTON
MAINLY OVER CASCADES AND FOOTHILLS AS WELL AS WHATCOM
COUNTY...COAST...AND THRU THE STRAIT OF JDF. AMS STABLE.
ABOUT A THIRD OF WESTERN WA SHOULD BE CLEAR THIS MORNING. OTHER
AREAS WILL BE A MIXED BAG OF LOW LEVEL MOISTURE. SOME SPOTS LIKE
AROUND KBLI HAVE 5K CIGS. ALONG THE COAST CIGS ARE AROUND
1.5K...CIGS IN THE STRAIT SHOULD BE SIMILAR. THEN YOU HAVE SOME FOG
AND BKN003 AROUND BURLINGTON AND KPAE. AND THIS JUST IN AT 3AM 3.2K
CIGS AT KSEA AND 1.5 MILES VSBY IN FOG AT KOLM. SO WITH THE MIXED
BAG OF LOW LEVEL MOISTURE...CONFIDENCE IN THIS MORNINGS FORECAST IS
LOW. ABOUT THE ONLY THING THAT IS FAIRLY CERTAIN IS MORE SUNSHINE BY
NOON.
KSEA...CIGS AROUND 3K THIS MORNING...THERE IS A CHANCE SOME LOWER
STUFF AROUND 500-1500 FT WILL CREEP IN AS WELL. SKIES SHOULD BE
GOING SCT AROUND 18Z.
&&
.MARINE...LOW LEVEL ONSHORE GRADIENTS DOWN THE STRAIT WILL BE ABOUT
THE SAME OR A BIT WEAKER TONIGHT THAN LAST NIGHT. SO W WINDS SHOULD
REMAIN BORDERLINE SMALL CRAFT ADVISORY EACH EVENING IN THE STRAIT
THROUGH FRIDAY.
A WEAKENING FRONT APPROACHING THE COAST FRIDAY NIGHT MAY BE STRONG
ENOUGH TO TURN WINDS SOUTHERLY ON THE COAST AND PERHAPS INLAND AS
WELL. FORECASTS REFLECT THIS TREND. MODELS ARE FAIRLY CONSISTENT
WITH THIS FEATURE AND HAVE ALSO BEEN CONSISTENT IN BRINGING A LITTLE
RAIN TO THE COAST AND OLYMPICS. WITH THE INCREASING SOUTHERLY FLOW
HAVE INDICATED TONIGHT AS BEING THE TIME WITH THE LEAST ONSHORE
COMPONENT.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...NONE.
$$
WEATHER.GOV/SEATTLE
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000
FXUS66 KPQR 241009
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
309 AM PDT THU JUL 24 2008
.SYNOPSIS...AFTER NEAR RECORD COOL TEMPERATURES THIS MORNING...TODAY
WILL WARM UP FAST UNDER MAINLY SUNNY SKIES INLAND. PATCHY LOW CLOUDS
WILL DEVELOP EARLY THIS MORNING...MAINLY NEAR THE NORTH COAST AND
POSSIBLY EXTEND UP THE COLUMBIA TO NEAR KELSO AND POSSIBLY BRIEFLY
THE PORTLAND METRO AREA. ANOTHER WARM AND MOSTLY SUNNY DAY IS
EXPECTED FRIDAY...BEFORE A PACIFIC FRONTAL SYSTEM STRENGTHENS ONSHORE
FLOW FOR THE DISTRICT. THIS WILL LEAD TO A COOLDOWN FOR THE
WEEKEND...ALONG WITH MORE CLOUDS AND THE POSSIBILITY OF COASTAL
DRIZZLE OR LIGHT RAIN FROM TIME TO TIME.
&&
.SHORT TERM...UPPER RIDGE BUILDING FAST OVER OREGON AND WASHINGTON
THIS MORNING AS UPPER LOW OVER SE BRITISH COLUMBIA EXITS EAST INTO
THE ROCKIES. THIS WILL RESULT IN A SIGNIFICANT WARMUP TODAY...ALONG
WITH A MUCH SHALLOWER MARINE LAYER.
BUT FIRST...TEMPERATURES ARE STARTING OFF QUITE COOL ACROSS THE
DISTRICT THIS MORNING. AS OF 2 AM TEMPS WERE ALREADY IN THE LOWER TO
MID 40S UP AND DOWN THE OREGON AND SW WASHINGTON COAST. SUSPECT 40S
WILL BE WIDESPREAD FOR MORNING LOWS INLAND AS WELL AS WINDS DIE DOWN.
CASCADES ARE COOL AS WELL...WITH BOULDER CREEK RAWS REPORTING TEMPS
IN THE UPPER 30S. WOULD NOT BE SURPRISED IF A FEW LOW TEMPERATURE
RECORDS FELL THIS MORNING...THE CURRENT RECORD LOW FOR DOWNTOWN
PORTLAND FOR JULY 24 IS 53 DEGREES...AND TEMPS WERE ALREADY INTO THE
MID 50S AS OF 2 AM THIS MORNING.
THE COOL MORNING TEMPS AND THE WARMER AIR MASS DEVELOPING ALOFT WILL
LIKELY LEAD TO A LARGE DIURNAL TEMPERATURE RANGE TODAY...WITH 30 TO
40 DEGREE SWINGS FROM MORNING LOW TO AFTERNOON HIGH COMMON ACROSS THE
DISTRICT. WITH A WARM AFTERNOON...AND A WARMER AIR MASS ALOFT...LOWS
FRI MORNING SHOULD BE A FEW DEGREES WARMER THAN THIS MORNING. UPPER
TROUGH APPROACHES THE COAST FRIDAY...BUT WILL PROBABLY BE TOO LATE TO
RESULT IN MUCH IN THE WAY OF CLOUD COVER OR SIGNIFICANT COOLING
FRIDAY. GFS/NAM SEEM TO BE DELAYING THIS UNTIL FRI NIGHT/SATURDAY...
AS SERIES OF UPPER VORT MAXES SWING THROUGH THE DISTRICT AND GENERAL
UPPER TROUGH AXIS MOVES ONSHORE. SATURDAY STILL LOOKS TO HAVE PLENTY
OF SUNSHINE INLAND...BUT THEN NAM BOUNDARY LAYER SATURATES OVERNIGHT
WITH DEEP MARINE LAYER AND PLENTY OF LOW CLOUDS SPREADING INLAND SAT
NIGHT/SUN. COASTAL DRIZZLE OR LIGHT RAIN MAY DEVELOP AS EARLY AS FRI
NIGHT AS MARINE LAYER DEEPENS...WITH ANOTHER ROUND POSSIBLE SAT
NIGHT/SUN MORNING. EXPECT MEASURABLE PRECIPITATION WILL HAVE A HARD
TIME MAKING IT EAST OF THE COAST RANGE...ESPECIALLY CONSIDERING THE
WEAK NATURE OF THE UPPER TROUGH AND CLIMATOLOGY FOR THIS TIME OF
YEAR...SO WILL LEAVE MENTION OF PRECIPITATION OUT OF FORECAST FOR THE
WILLAMETTE VALLEY AND CLARK COUNTY LOWLANDS. WEAGLE
.LONG TERM...MODEL CONSENSUS SHOWS GENERAL WEST TO SOUTHWEST FLOW
ALOFT ACROSS DISTRICT THROUGH NEXT WEEK. 00Z GFS SHOWS SOME HINT OF
UPPER RIDGING BUILDING NORTH FROM THE GREAT BASIN AROUND
MIDWEEK...WITH UPPER TROUGH DEVELOPING OVER GULF OF ALASKA. EVEN WITH
AN INCREASINGLY AMPLIFIED JET PATTERN...IT STILL APPEARS GENERAL
PATTERN REMAINS ONSHORE AT THE SURFACE...PREVENTING ANY MAJOR WARMUP
NEXT WEEK. MODELS HAVE HINTED AT A FRONTAL SYSTEM APPROACHING COAST
WED/THU...BUT HAVE BEEN INCONSISTENT ON STRENGTH/TIMING UP TO THIS
POINT. WEAGLE
&&
.AVIATION...MOSTLY CLEAR OVER THE CWA THIS MORNING. LOCAL MVFR CIGS
DEVELOPING JUST NORTH OF KAST. EXPECT MVFR CIGS TO FORM ALONG THE
COAST AFTER 10Z AND MOVE UP THE COLUMBIA RIVER TO NEAR KKLS BY 12Z
AND POSSIBLY TOUCH THE KPDX AREA A FEW HOURS LATER. CIGS SHOULD
DISSIPATE INLAND BY LATE MORNING... AND LIFT ON THE COAST BY
AFTERNOON AND MOVE JUST OFFSHORE LATER THIS AFTERNOON.
KPDX AND APPROACHES...CLEAR SKIES PREVAIL THIS MORNING. AFTER
14Z...LOCAL AREAS OF MVFR CIGS MAY DEVELOP DUE TO MARINE STRATUS
ESPECIALLY WESTERN APPROACHES...BUT THEY WILL BURN OFF BY 17Z.
&&
.MARINE...HIGH PRESSURE OVER THE COASTAL WATERS WEAKENS SLIGHTLY
TODAY AS A WEAK FRONT APPROACHES FROM THE W. THE HIGH WEAKENS
SIGNIFICANTLY FRI AND SHIFTS EAST AS THE VERY WEAK FRONT MOVES OVER
THE COASTAL WATERS. HIGH PRES REBUILDS SAT AND ANOTHER FRONT
APPROACHES THE COASTAL WATERS LATE SUN. SEAS REMAIN BELOW 10 FT FOR
THE FORESEEABLE FUTURE.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR/WA...SMALL CRAFT ADVISORY FOR WINDS FROM CASCADE HEAD TO FLORENCE
THIS AFTERNOON AND EVENING.
&&
.PRELIMINARY POINT POPS (PROBABILITY OF MEASURABLE PRECIPITATION)
AST 0--34 PDX 000-1 SLE 000-1 EUG 000-1
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KOTX 240923
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
223 AM PDT THU JUL 24 2008
.SYNOPSIS...
A WARMING AND DRYING TREND WILL COMMENCE TODAY AND LAST THROUGH
AND PEAK ON FRIDAY WITH ABOVE NORMAL TEMPERATURES. THIS TREND
WILL MODERATE DURING THE WEEKEND...WHICH WILL REMAIN DRY AND
SLIGHTLY WARMER THAN AVERAGE.
&&
.DISCUSSION...
TODAY AND TONIGHT...THE UPPER LEVEL WAVE WHICH BROUGHT YESTERDAY`S
THUNDERSTORM ACTIVITY TO THE NORTHERN ZONES IS CURRENTLY
SKITTERING EASTWARD INTO THE PRAIRIE PROVINCES. A BACK SIDE
VORTICITY LOBE LIES JUST NORTH OF THE IDAHO PANHANDLE AND MAY
PROVIDE ENOUGH LIFT FOR A STRAY SHOWER OR SPRINKLE OVER THE
EXTREME NORTHEAST ZONES EARLY THIS MORNING...BEFORE THE ENTIRE
SYSTEM DEPARTS AND ALLOWS A SHARP SHORT WAVE RIDGE TO BUILD BACK
OVER THE FORECAST AREA BY THIS AFTERNOON. NAM AND GFS ARE SIMILAR
AND APPEAR PLAUSIBLE AGAINST SATELLITE EXTRAPOLATION FOR THE NEXT
24 TO 36 HOURS FEATURING THIS RIDGE ALOFT AND THE RETURN OF THE
SURFACE THERMAL TROUGH BUILDING INTO THE FAR WESTERN ZONES TODAY.
THE AIR MASS WILL BE LARGELY STABILIZING UNDER THE RIDGE
ALOFT...BUT SOME REMAINING IN-SITU LOW LEVEL MOISTURE MAY GIN UP
INTO SOME FLAT CUMULUS THIS AFTERNOON OVER THE HIGHER TERRAIN OF
THE EAST BASIN AND OVER THE MOUNTAIN ZONES. OTHERWISE MOSTLY
SUNNY...LIGHT WINDS AND MAX TEMPERATURES RECOVERING FROM
YESTERDAY`S ABNORMALLY COOL READINGS TO VALUES AT OR NEAR SEASONAL
AVERAGES. TONIGHT LITTLE CHANGE IN THE DRY AND PLACID
REGIME...WITH THE SURFACE THERMAL TROUGH STRENGTHENING OVER THE
CASCADES WHICH MAY PRODUCE NEAR BREEZY EASTERLY WINDS OVER THE
PALOUSE AND THROUGH THE PURCELL TRENCH AT COEUR D`ALENE BY DAWN.
FRIDAY THROUGH SUNDAY...ONCE AGAIN ALL EYES ARE SET ON THE SYSTEM
NOW ENCROACHING ON 140W OVER THE PACIFIC...AS IT WILL LIKELY BE
THE MAIN PLAYER IN THE WEATHER THROUGH THIS PORTION OF THE
FORECAST. THE CURRENT LONGITUDINAL STRETCHING PATTERN NOTED ON
WATER VAPOR WITH THIS SYSTEM ALREADY SUGGESTS THE MID-LEVEL ENERGY
IS IN THE PROCESS OF ROUNDING THE BASE OF THE UPPER LEVEL TROUGH
OVER THE PACIFIC...AND WITH THE MID-LEVEL ENERGY GETTING
STRETCHED...THE SYSTEM HAS LIKELY ALREADY PEAKED IN INTENSITY. AS
THE STRETCHED SYSTEM GRADUALLY SHEARS OUT EASTWARD...ALL MODELS
CARRY SHORT WAVE ENERGY TOWARD THE CWA LATE FRIDAY NIGHT/EARLY
SATURDAY. AHEAD OF THIS SHORT WAVE TROUGH...WARM ADVECTION AND
RIDGING DRIVE 850 MB TEMPERATURES UP TO +24C ON THE GFS AND ECMWF
FRIDAY AFTERNOON WITH SOUNDINGS SUPPORTING A WELL MIXED ATMOSPHERE
BELOW THAT LAYER. ADDITIONALLY...GEFS MEAN 850 MB TEMPERATURES
UNDER THE PEAKING RIDGE FRIDAY AFTERNOON ARE ACTUALLY A TAD WARMER
THAN THE GFS OR ECMWF...WHICH IS VERY STRANGE GIVEN THE ALREADY
STRONG RIDGE DEPICTED ON THE GFS. THIS SUGGESTED THE ENSEMBLE
SOLUTIONS FAVOR AN EVEN STRONGER SHORT WAVE RIDGE THAN THE GFS
DEPICTS...SO HIGH TEMPERATURES HAVE BEEN BUMPED UP A DEGREE OR TWO
OVERALL FOR FRIDAY FROM THE PREVIOUS FORECAST PACKAGE.
AS THE SYSTEM PASSES FRIDAY NIGHT AND THROUGH THE DAY
SATURDAY...HEIGHTS AND LAYER TEMPERATURES FALL OFF ACCORDINGLY.
WITH MID-LEVEL COOLING AND ADDITIONAL MID-LEVEL MOISTURE INFLUX
PER THE GFS WITH FLOW TURNING MORE OFF THE PACIFIC...MID AND HIGH
BASED CLOUDS WILL LIKELY BE FAIRLY COMMON FRIDAY NIGHT
TRANSITIONING TO MORE OF AN AFTERNOON CUMULUS REGIME BY SATURDAY
AS MOISTURE ASSOCIATED WITH THE SYSTEM WANES AND AFTERNOON
INSTABILITY DOMINATES DUE TO THE COOLER AIR ALOFT MOVING IN AND
STRONGER MID-LEVEL THETA-E LAPSE RATES. THE PATTERN THAT HAS
DOMINATED THE AREA RECENTLY THEN TAKES HOLD AGAIN WITH WEAK WAVES
IN SOUTHWESTERLY FLOW ALOFT DAMPENING ANY SIGNIFICANT RIDGING OVER
THE AREA...YIELDING DRY CONDITIONS OVERALL WITH A DEARTH OF
BOUNDARY LAYER MOISTURE AND RATHER SEASONABLE TEMPERATURES THROUGH
MID-WEEK NEXT WEEK AFTER WHICH TIMES THE MODELS BEGIN TO TREND
BACK TOWARD A STRONGER FOUR CORNERS HIGH DEVELOPING AND RIDGING
DOMINATING THE AREA AGAIN BY THE END OF THE WEEK. /FRIES
&&
.AVIATION...
THE UPPER LEVEL LOW IS EXITING THE REGION AND CONVECTIVE SHOWERS
ARE JUST ABOUT DONE FOR THE EVENING. EXPECT MAINLY CLEAR SKIES...THE
EXCEPTION WILL BE ACROSS THE NORTHERN VALLEYS WHERE SOME PRECIPITATION
WAS OBSERVED EARLIER TODAY AND THERE IS A POTENTIAL FOR FOG/STRATUS
DEVELOPMENT BETWEEN 10Z-14Z...OTHERWISE VFR CONDITIONS EXPECTED AT
ALL TAF SITES THROUGH 06Z FRIDAY. /TOBIN
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 82 57 93 63 87 60 / 0 0 0 0 0 0
COEUR D`ALENE 81 53 93 58 86 59 / 0 0 0 0 0 0
PULLMAN 81 48 92 53 86 53 / 0 0 0 0 0 0
LEWISTON 89 61 100 66 93 64 / 0 0 0 0 0 0
COLVILLE 89 50 94 54 90 54 / 10 0 0 0 0 0
SANDPOINT 80 47 90 54 84 54 / 10 0 0 0 0 10
KELLOGG 79 55 92 60 83 58 / 0 0 0 0 0 0
MOSES LAKE 87 54 97 62 91 61 / 0 0 0 0 0 0
WENATCHEE 87 60 95 65 88 64 / 0 0 0 0 0 0
OMAK 90 54 97 58 91 57 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
000
FXUS66 KOTX 240550
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1050 PM PDT WED JUL 23 2008
.SYNOPSIS...
A TROUGH WILL PASS ALONG THE CANADIAN BORDER OVER THE NEXT 12
HOURS...KEEPING THE THREAT OF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS IN THE FORECAST. EXPECT A DRYING TREND THE REST OF THE
WORK WEEK.
&&
.DISCUSSION... THE UPPER TROUGH CONTINUES IT`S EASTWARD TREK
ALONG THE CANADIAN BORDER...AND IS SLOWLY PULLING AWAY FROM THE
AREA. LOCAL RADAR AND SATELLITE INDICATES THAT A FEW STRAY SHOWERS
ARE POSSIBLE ACROSS EXTREME NORTHEAST BOUNDARY COUNTY. BUT FOR THE
MOST PART SKIES ARE CLEARING AS HIGH PRESSURE RAPIDLY BUILDS INTO
THE CASCADES. THE PREVIOUS SHIFT HAD REDUCED POPS TO NEAR ZERO AFTER
06Z AND THAT LOOKS TO BE THE WAY TO GO. A FEW UPDATES WERE MADE
EARLIER THIS EVENING AND NO ADDITIONAL UPDATES WILL BE
FORTHCOMING. /TOBIN
.AVIATION...
THE UPPER LEVEL LOW IS EXITING THE REGION AND CONVECTIVE SHOWERS
ARE JUST ABOUT DONE FOR THE EVENING. EXPECT MAINLY CLEAR SKIES...THE
EXCEPTION WILL BE ACROSS THE NORTHERN VALLEYS WHERE SOME PRECIPITATION
WAS OBSERVED EARLIER TODAY AND THERE IS A POTENTIAL FOR FOG/STRATUS
DEVELOPMENT BETWEEN 10Z-14Z...OTHERWISE VFR CONDITIONS EXPECTED AT
ALL TAF SITES THROUGH 06Z FRIDAY. /TOBIN
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 52 83 58 92 62 87 / 10 0 0 0 0 0
COEUR D`ALENE 51 83 55 92 56 86 / 30 0 0 0 0 0
PULLMAN 45 83 49 92 53 86 / 0 0 0 0 0 0
LEWISTON 58 91 60 99 66 93 / 0 0 0 0 0 0
COLVILLE 47 87 50 94 55 90 / 60 0 0 0 0 0
SANDPOINT 48 81 49 89 55 84 / 60 0 0 0 0 0
KELLOGG 54 81 56 91 59 83 / 20 0 0 0 0 0
MOSES LAKE 53 89 58 94 60 91 / 0 0 0 0 0 0
WENATCHEE 60 89 63 94 65 88 / 0 0 0 0 0 0
OMAK 53 90 56 94 57 91 / 40 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
000
FXUS66 KPQR 240403
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
900 PM PDT WED JUL 23 2008
.SYNOPSIS...AN UPPER LEVEL RIDGE WILL BUILD OVER AREA TONIGHT AND
STRENGTHEN OVER CENTRAL AND EASTERN OREGON THURSDAY. THERMAL TROUGH
BUILDS OVER CENTRAL OREGON THURSDAY REDUCING ONSHORE FLOW AND
BRINGING WARMER AIR MASS TO AREA. SOUTHWEST FLOW ALOFT BEGINS TO
INCREASE THURSDAY NIGHT AND INCREASES FURTHER ON FRIDAY. SHALLOW
MARINE AIR MASS ALONG COAST THURSDAY NIGHT DEEPENS ALONG COAST FRIDAY
AS ONSHORE FLOW INCREASES. PACIFIC FRONT APPROACHES NORTHERN
COAST LATER FRIDAY NIGHT AND MOVES INTO COASTAL AREA EARLY SATURDAY
BEFORE WEAKENING OVER COASTAL AREA MIDDAY SATURDAY. MODERATELY STRONG
ONSHORE FLOW CONTINUES OVER AREA SATURDAY. DEEPENING MARINE AIR MASS
MOVES OVER AREA SATURDAY NIGHT. HIGH PRESSURE BUILDS FURTHER NORTH
SUNDAY DECREASING ONSHORE FLOW ESPECIALLY SOUTH PART. STRONGER HIGH
PRESSURE OVER AREA MONDAY. INCREASING WEST FLOW WILL BRING STRONGER
ONSHORE FLOW TO AREA TUESDAY AND WEDNESDAY.
&&
.SHORT TERM...UPPER RIDGE STARTING TO BUILD OVER AREA TONIGHT BUILDS
FURTHER OVER CENTRAL AND EASTERN ORE THU. MARINE CLOUDS LIMITED TO
OFF NORTHERN COAST WILL PUSH BACK ASHORE LATER TONIGHT THEN DOWN COL
RIVER THU MORNING. COOL AMS OVER AREA TONIGHT AND WITH MOSTLY CLEAR
SKIES TEMPS WILL BE QUITE COOL THU MORNING WITH SOME APPROACHING
RECORD LOWS. THERMAL TROUGH DEVELOPS OVER CENTRAL ORE THU AFTERNOON.
ONSHORE FLOW WEAKER WITH MOST MARINE CLOUDS GONE BY THU AFTERNOON.
WARMER AMS OVER AREA THOUGH TEMPS WILL HAVE TO RECOVER FROM COOL
START THU MORNING. SW FLOW ALOFT BEGINS TO INCREASE THU NIGHT. MARINE
AMS STILL SHALLOW ALONG COAST WILL KEEP STRATUS/FOG CONFINED TO
MAINLY COASTAL AREAS. SW FLOW ALOFT INCREASE FURTHER ON FRI. THERMAL
TROUGH SHIFTS TO IDA BORDER FRI AFTERNOON WITH ONSHORE FLOW
INCREASING. MARINE AMS SLOW DEEPENS ALONG COAST. WITH SHALLOW START
OF MARINE AIR WILL ALLOW COASTAL AREAS TO PARTIALLY CLEAR FRI
AFTERNOON THOUGH MC STILL POSSIBLE. GFS/NGM MOS SUPPORT A LITTLE MORE
CLEARING THEN DEEPER MARINE AMS WITH NAM. INLAND TEMPS FRI SIMILAR TO
THU OR A BEST JUST A LITTLE COOLER. PAC FRONT APPROACHES NORTHERN
COAST LATER FRI NIGHT. NAM/GFS/EURO ALL SIMILAR WITH SOME
PRECIPITATION THREAT LATER FRI NIGHT NORTHERN COAST. FRONT MOVES INTO
COASTAL AREA SAT MORNING WITH PRECIPITATION THREAT THEN INITIAL FRONT
DISSIPATES OVER COAST AREA BY EARLY SAT AFTERNOON. FAIRLY STRONG
ONSHORE FLOW WILL CONTINUE SAT AFTERNOON BRINGING COOLER TEMPS TO
INLAND AREAS. CLOUDS TRICKY FOR SAT. COASTAL AREAS REMAIN FAIRLY
CLOUDY WITH FRONT AND STRONGER ONSHORE FLOW. INLAND AREAS WILL BRING
BROKEN CLOUDS IN THE NORTH IN THE MORNING AS FRONT HANGS OVER THE
COAST RANGE THEN SOMEWHAT LESS CLOUDS IN THE AFTERNOON. WILL BROAD
BRUSH THE DAY AS PARTLY SUNNY INLAND WITH MORE SUN S PART. KOSOVITZ
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
THE UPPER TROUGH FROM LATE IN THE SHORT TERM PERIOD IS
STILL AROUND EARLY IN THE EXTENDED PERIOD...WITH A SHORT WAVE MOVING
THROUGH SATURDAY NIGHT THAT COULD PRODUCE A TOUCH OF DRIZZLE NEAR THE
NORTHERN MOUNTAINS. MAY SEE A BIT MORE SUNSHINE SUNDAY AFTERNOON
INLAND BUT TEMPS WILL BE TOUGH TO REACH NORMAL. HAVE LEFT THE
REMAINDER OF THE EXTENDED ALONE...WHICH REFLECTS NEAR NORMAL TEMPS
AND A MODERATE ONSHORE FLOW FOR LATE NIGHT AND MORNING LOW CLOUDS.
THE GFS MODEL LOOKS TOO STRONG ON A SYSTEM EARLY NEXT WEEK...WHILE
THE ECMWF IS MUCH WARMER...AND OPTED FOR A MIDDLE OF THE ROAD
SOLUTION THAT IS DRY BUT NEAR CLIMO. MAIN MESSAGE IS MODELS MAINTAIN
A WESTERLY FLOW ALOFT FOR A WHILE THAT ENCOURAGES SOME ONSHORE FLOW
WITH THE WEATHER NEAR NORMAL. TOLLESON
&&
.AVIATION...WIDESPREAD CLEARING THIS EVENING SHOULD CONTINUE THROUGH
THE NEXT FEW HOURS BEFORE MARINE STRATUS ONCE AGAIN MAKES AN
APPEARANCE...THOUGH SHOULD NOT AFFECT MOST OF THE FORECAST AREA
TONIGHT. EXPECT MVFR CIGS TO REFORM ALONG THE COAST AFTER 06Z AND
BEGIN TO MOVE INLAND. MVFR CIGS MAY FLIRT WITH IFR ALONG THE COAST
TOWARD MORNING. INLAND EXPECT MARINE STRATUS INTRUSION TO BE MUCH
LESS THAN THE LAST FEW NIGHTS...AND SHOULD BE MAINLY DOWN THE
COLUMBIA RIVER TO KKLS BY 12Z AND POSSIBLE TOUCH THE KPDX AREA A FEW
HOURS LATER. CIGS SHOULD DISSIPATE INLAND BY EARLY AFTERNOON THU...
AND LIFT ON THE COAST ON MOVE JUST OFFSHORE LATER AFTERNOON THU.
KPDX AND APPROACHES...CLEAR SKIES WILL CONTINUE FOR THE MAJORITY OF
TONIGHT. AFTER 14Z AREAS OF MVFR CIGS MAY DEVELOP DUE TO MARINE
STRATUS ESPECIALLY WESTERN APPROACHES...BUT THEY WILL BURN OFF BY
17Z. BROWN
&&
.MARINE...HIGH PRESSURE OVER THE COASTAL WATERS WEAKENS SLIGHTLY THU
AS A WEAK FRONT APPROACHES FROM THE W. ON FRI THE HIGH WEAKENS
SIGNIFICANTLY AND SHIFTS EAST AS THE VERY WEAK FRONT MOVES OVER THE
COASTAL WATERS. HIGH PRES REBUILDS SAT AND ANOTHER FRONT APPROACHES
THE COASTAL WATERS LATE SUN. SEAS REMAIN BELOW 10 FT FOR THE
FORESEEABLE FUTURE. DK2
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR/WA...SMALL CRAFT ADVISORY FOR WINDS FROM CASCADE HEAD TO FLORENCE
THROUGH THIS EVENING.
&&
.PRELIMINARY POINT POPS (PROBABILITY OF MEASURABLE PRECIPITATION)
AST ----24 PDX 0000-1 SLE 0000-1 EUG 0000--
$$
MORE WEATHER INFORMATION ONLINE AT...
Http://weather.gov/portland
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KSEW 240352
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
845 PM PDT WED JUL 23 2008
.SYNOPSIS...A RIDGE WILL BRING CLEAR SKIES TONIGHT AND THURSDAY. A
WEAK FRONT ARRIVING EARLY SATURDAY WILL INCREASE CLOUDS OVER THE
AREA AND BRING A CHANCE OF RAIN TO THE COAST. A SERIES OF WEAK UPPER
LEVEL SYSTEMS MOVING THROUGH THE PACIFIC NORTHWEST SUNDAY AND MONDAY
WILL KEEP CONDITIONS ON THE CLOUDY AND COOL SIDE INTO THE EARLY PART
OF NEXT WEEK.
&&
.SHORT TERM...CLOUDS OVER PUGET SOUND HAVE MOSTLY EVAPORATED. EAST
OF THERE THE CLOUD SHIELD IS HANGING TOUGH AND COULD LAST SEVERAL
MORE HOURS OVER THE CASCADES. HOWEVER UPPER AND SURFACE RIDGE ARE
BUILDING AND SKIES WILL BE SUNNY ON THURSDAY. CLEAR SKIES WILL LAST
INTO THURSDAY NIGHT AND PART OF FRIDAY. HIGHS IN THE INTERIOR WILL
BE IN THE MID TO UPPER 70S WITH A FEW 80S.
APPROACHING FRONT WILL LIKELY START TO SPREAD CLOUDS OVER THE AREA
ON FRIDAY. THIS FRONT IS NOT STRONG BUT COULD EASILY RAIN A LITTLE
ON THE COAST AND IN THE OLYMPICS. MORE CLOUDS WILL KEEP TEMPS A FEW
DEGREES LOWER ON FRIDAY. ON SATURDAY HEIGHTS ARE DEPRESSED AND
CLOUDS WILL BE THICKER FOR HIGHS SEVERAL DEGREES LOWER. BURKE
.LONG TERM...PREVIOUS DISCUSSION...MOIST ONSHORE FLOW AND COOL TEMPS
WILL PERSIST INTO SUNDAY. BOTH THE 12Z GFS AND ECMWF BRUSH A WEAK
SHORTWAVE ONSHORE SUNDAY MORNING...BRINGING SOME LIGHT PRECIPITATION
MOSTLY TO THE COAST AGAIN SUNDAY MORNING. THE GFS IS MUCH LIGHTER
THAN THE ECMWF... WITH THE LATTER BRINGING PRECIP INTO THE NORTHWEST
INTERIOR. LOOKS LIKE AT BEST THIS WILL BE DRIZZLE AND MAY BE HARD TO
MEASURE. FOR NOW LEFT SUNDAY MORNING DRY IN THE FORECAST PACKAGE.
THE ONSHORE GRADIENTS REMAIN STRONGER IN THE 12Z GFS VS THE
ECMWF...MAINTAINING A MORE PESSIMISTIC FORECAST FOR BREAK OUT DURING
THE AFTERNOON ON SUNDAY. TRENDED TOWARDS THE GFS IDEA WITH LITTLE
BREAK OUT SUNDAY NIGHT. UPPER LEVEL TROUGH OVER THE GULF OF ALASKA
AND NE PACIFIC SLOW TO MOVE OUT...DIGGING DOWN ALONG 130 W BY
MIDWEEK. EXPECT GENERALLY DRY WEATHER WITH MORNING CLOUDS AND
AFTERNOON SUNSHINE. SEASONAL TEMPERATURES.
&&
.AVIATION...UPPER TROUGH IN EASTERN WASHINGTON MOVING EAST WITH
HEIGHTS BUILDING OVER WESTERN WASHINGTON. LIGHT NORTHWESTERLY FLOW
ALOFT WITH ONSHORE SURFACE FLOW. AIR MASS STABLE. AREAS OF LOW LEVEL
MOISTURE WESTERN WASHINGTON EVAPORATING BY 06Z.
STRATUS HAS GONE FROM THE COAST AND STRAIT AND IS ERODING AWAY OVER
PUGET SOUND. LOOKING AT BROKEN SKIES GOING TO SCATTERED AT NOAA
SANDPOINT...WITH SOME MORE CLEARING OVERNIGHT. MAINLY CLEAR IN THE
EARLY MORNING WITH POSSIBLY PATCHES OF STRATUS NEAR MARINE AREAS.
KSEA...3.5K FT BKN CLOUD DECK SHOULD SCATTER OUT BY 05Z LEAVING JUST
A FEW CLOUDS AROUND 4.5K FT IN THE MORNING HOURS.
&&
.MARINE...LOW LEVEL ONSHORE GRADIENTS DOWN THE STRAIT WILL BE ABOUT
THE SAME AGAIN TONIGHT AS TUE NIGHT. SO W WINDS SHOULD REMAIN AT
SMALL CRAFT ADVISORY LEVELS. OTHERWISE..EXPECT FLOW WILL REMAIN
ONSHORE THROUGH FRIDAY WITH BORDERLINE SMALL CRAFT ADVISORY WINDS
EACH EVENING IN THE STRAIT.
A WEAKENING FRONT APPROACHING THE COAST FRIDAY NIGHT MAY BE STRONG
ENOUGH TO TURN WINDS SOUTHERLY ON THE COAST AND PERHAPS INLAND AS
WELL. FORECASTS REFLECT THIS TREND. MODELS ARE FAIRLY CONSISTENT
WITH THIS FEATURE AND HAVE ALSO BEEN CONSISTENT IN BRINGING A LITTLE
RAIN TO THE COAST AND OLYMPICS. WITH THE INCREASING SOUTHERLY FLOW
HAVE INDICATED THURSDAY NIGHT AS BEING THE TIME WITH THE LEAST
ONSHORE COMPONENT.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY CENTRAL AND EAST STRAIT.
$$
WEATHER.GOV/SEATTLE
000
FXUS66 KOTX 240318
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
818 PM PDT WED JUL 23 2008
.SYNOPSIS...
A TROUGH WILL PASS ALONG THE CANADIAN BORDER OVER THE NEXT 12
HOURS...KEEPING THE THREAT OF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS IN THE FORECAST. EXPECT A DRYING TREND THE REST OF THE
WORK WEEK.
&&
.DISCUSSION...
THE UPPER TROUGH CONTINUES IT`S EASTWARD TREK ALONG THE CANADIAN
BORDER. INSTABILITY ASSOCIATED WITH THE TROUGH PASSAGE AND GOOD
RADIATIONAL WARMING AT THE SURFACE IS WANING AS SUNSET APPROACHES.
IN ADDITION THE WEAK SHORT WAVE THAT ACTED AS A KICKER TO GET
CONVECTION GOING HAS EXITED THE REGION AS WELL. ANOTHER WEAK WAVE
CAN BE SEEN ROUNDING THE BACK OF A TROUGH...SO WHILE THE
INSTABILITY IS LEAS THAN EARLIER THIS AFTERNOON THERE IS STILL
ENOUGH TO HANG ONTO ISOLATED WORDING FOR THE NORTHERN MOUNTAIN
ZONES. A FEW ADJUSTMENTS WERE MADE TO TEMPERATURES AND WINDS...BUT
THESE WERE MINOR...OTHERWISE THE FORECAST IS IN GOOD SHAPE WITH
CLEARING SKIES AS HIGH PRESSURE QUICKLY BUILDS INTO THE REGION.
&&
.AVIATION...
ISOLATED SHOWERS AND THUNDERSTORMS WILL CONTINUE NORTH OF THE
COLUMBIA BASIN FROM THE EAST SLOPES OF THE NORTHERN CASCADES EAST
TO THE NORTHERN PANHANDLE MOUNTAINS OF IDAHO THROUGH 06Z. AFTER
06Z EXPECT CLEARING SKIES. ACROSS THE NORTHERN VALLEYS WHERE SOME
PRECIPITATION WAS OBSERVED FOG/STRATUS ARE EXPECTED O DEVELOP
AROUND 10Z AND LAST UNTIL 14Z...OTHERWISE VFR CONDITIONS EXPECTED
AT ALL TAF SITES THROUGH 06Z FRIDAY. /TOBIN
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 52 83 58 92 62 87 / 10 0 0 0 0 0
COEUR D`ALENE 51 83 55 92 56 86 / 30 0 0 0 0 0
PULLMAN 45 83 49 92 53 86 / 0 0 0 0 0 0
LEWISTON 58 91 60 99 66 93 / 0 0 0 0 0 0
COLVILLE 47 87 50 94 55 90 / 60 0 0 0 0 0
SANDPOINT 48 81 49 89 55 84 / 60 0 0 0 0 0
KELLOGG 54 81 56 91 59 83 / 20 0 0 0 0 0
MOSES LAKE 53 89 58 94 60 91 / 0 0 0 0 0 0
WENATCHEE 60 89 63 94 65 88 / 0 0 0 0 0 0
OMAK 53 90 56 94 57 91 / 40 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
000
FXUS66 KOTX 232331 AAA
AFDOTX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SPOKANE WA
431 PM PDT WED JUL 23 2008
.SYNOPSIS...
A TROUGH WILL PASS ALONG THE CANADIAN BORDER OVER THE NEXT 12
HOURS...KEEPING THE THREAT OF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS IN THE FORECAST. EXPECT A DRYING TREND THE REST OF THE
WORK WEEK.
&&
.DISCUSSION...
UPDATED AVIATION DISCUSSION.
TONIGHT THROUGH FRIDAY NIGHT...UPPER LEVEL TROUGH WILL CONTINUE
ITS EASTWARD PROGRESSION ALONG THE US/CANADIAN BORDER THIS EVENING
AND OVERNIGHT. SCATTERED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED
THIS AFTERNOON ACROSS THE NORTHEAST CASCADES EAST TOWARDS THE
OKANOGAN HIGHLANDS. AS THE TROUGH PUSHES EAST THROUGH THE
EVENING...SO WILL THE SHOWERS AND THUNDERSTORMS...EAST TOWARDS THE
NORTHEAST MOUNTAINS AND THE NORTH IDAHO PANHANDLE. NAM12 CAPE
VALUES OF AROUND 1000 J/KG AND LI`S OF -2 TO -3 C COUPLED WITH THE
WESTERLY STEERING FLOW FROM THE BASE OF THE TROUGH WILL KEEP
THUNDERSTORMS GOING TILL AROUND 11PM TONIGHT. THUNDERSTORMS WILL
CONTAIN BRIEF HEAVY RAIN AND SMALL HAIL ALONG WITH FREQUENT CLOUD TO
GROUND LIGHTNING. BY THURSDAY MORNING THE TROUGH WILL BE ALONG THE
WESTERN MONTANA/CANADIAN BORDER WITH A RIDGE REBUILDING ACROSS THE
WEST COAST. THE RIDGE WILL REMAIN OVER THE INLAND NORTHWEST
THROUGH FRIDAY FOR AN INCREASE IN TEMPERATURES EACH DAY RESULTING
IN TEMPERATURES RETURNING TO ABOVE AVERAGE READINGS FOR THIS TIME
OF THE YEAR. /NISBET
SATURDAY THROUGH WEDNESDAY...THE REGION WILL BE UNDER SOUTHWEST
FLOW ALOFT THROUGH MUCH OF THE EXTENDED PERIOD. ON SATURDAY THE
RIDGE AXIS WILL BE NUDGED EAST TO MONTANA. MID LEVEL HEIGHTS WILL
FALL AS A SHORTWAVE TROUGH MOVES THROUGH THE INLAND NORTHWEST
SATURDAY NIGHT AND SUNDAY. MOISTURE WILL BE LIMITED SO THE MAIN
EFFECT WILL BE COOLER TEMPERATURES AND AN INCREASE IN WINDS FOR
THE CASCADE GAPS DURING THE OVERNIGHT HOURS THROUGH THE WEEKEND.
THERE MAY BE A STRAY THUNDERSTORM ACROSS THE NORTHERN PANHANDLE OF
IDAHO SUNDAY AFTERNOON AS A VORT MAX CLIPS OUR NORTHEAST CORNER.
THE NEXT CHANCE OF PRECIPITATION WILL HOLD OFF UNTIL MIDWEEK WHEN
A TROUGH OF LOW PRESSURE APPROACHES THE PACIFIC NORTHWEST. THERE
IS A GOOD FETCH OF PRECIPITABLE WATER WITH THIS FEATURE BUT IT
APPEARS TO HAVE A DIFFICULT TIME GETTING PAST THE CASCADES. AT
THIS POINT THE FORECAST WILL REMAIN DRY. TEMPERATURES WILL CONTINUE
NEAR SEASONAL NORMALS THROUGH WEDNESDAY. /KELCH
&&
.AVIATION...
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE NORTH OF THE
COLUMBIA BASIN FROM THE EAST SLOPES OF THE NORTHERN CASCADES EAST
TO THE NORTHERN PANHANDLE MOUNTAINS OF IDAHO THIS
EVENING...DIMINISHING AFTER SUNSET. VFR CONDITIONS EXPECTED AT ALL
TAF SITES THROUGH 00Z FRIDAY. /EK
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 53 83 58 92 62 87 / 10 0 0 0 0 0
COEUR D`ALENE 51 83 55 92 56 86 / 30 0 0 0 0 0
PULLMAN 45 83 49 92 53 86 / 0 0 0 0 0 0
LEWISTON 58 91 60 99 66 93 / 0 0 0 0 0 0
COLVILLE 47 87 50 94 55 90 / 60 0 0 0 0 0
SANDPOINT 48 81 49 89 55 84 / 60 0 0 0 0 0
KELLOGG 54 81 56 91 59 83 / 20 0 0 0 0 0
MOSES LAKE 53 89 58 94 60 91 / 0 0 0 0 0 0
WENATCHEE 60 89 63 94 65 88 / 0 0 0 0 0 0
OMAK 53 90 56 94 57 91 / 40 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
000
FXUS66 KSEW 232243
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 PM PDT WED JUL 23 2008
.SYNOPSIS...A WEAK UPPER LEVEL RIDGE WILL SETTLE IN OVER THE PACIFIC
NORTHWEST TONIGHT INTO THURSDAY. RISING HEIGHTS OVER WESTERN
WASHINGTON COUPLED WITH DRIER NORTHWEST FLOW WILL HELP ERODE THE
MARINE LAYER AND CLOUDS THIS EVENING GIVING WAY TO SUNNY AND WARMER
WEATHER THROUGH FRIDAY. A WEAK FRONTAL SYSTEM MOVING INTO WESTERN
WASHINGTON EARLY SATURDAY WILL BRING INCREASED CLOUDINESS TO THE
AREA AND A CHANCE OF RAIN TO THE COAST. A SERIES OF WEAK UPPER LEVEL
SYSTEMS MOVING THROUGH THE PACIFIC NORTHWEST SUNDAY AND MONDAY WILL
KEEP CONDITIONS ON THE CLOUDY AND COOL SIDE INTO THE EARLY PART OF
NEXT WEEK.
&&
.SHORT TERM...MARINE STRATUS STUBBORNLY LINGERING OVER MOST INLAND
AREAS AS OF 23Z...MOST CLEARING OCCURING ALONG THE NORTH AND CENTRAL
COAST...STRAIT...AND NORTHERN INLAND WATERS. BUILDING UPPER HEIGHTS
AND WEAK W/NW PRESSURE GRADIENTS WILL HELP REMAINING AREAS BREAK
OUT...JUST A BIT LATER THAN PREVIOUSLY THOUGHT. UNLIKE LAST NIGHT
THE DRIER N/NW FLOW OVERNIGHT WILL HELP KEEP MOST AREAS CLEAR AS
THEY BREAK OUT THIS EVENING. EXPECT THE MARINE STRATUS TO REFORM
ONLY ALONG THE COAST EARLY THURSDAY MORNING AND BURN OFF BY MIDDAY.
ELSEWHERE...THE LACK OF MORNING STRATUS AND THE BUILDING HIGH
PRESSURE OVER WESTERN WASHINGTON WILL GIVE TEMPS A BUMP THURSDAY.
AREAS AWAY FROM THE WATER COULD RISE TO AROUND 80...WITH MID TO
UPPER 70S ELSEWHERE. THE WEAK N/NW FLOW WILL LIKELY LIMIT THE TEMPS
FROM SOARING TOO MUCH. SUNNIER AND WARMER WEATHER WILL CONTINUE INTO
FRIDAY. AN UPPER LEVEL TROUGH SAGGING DOWN INTO THE GULF OF ALASKA
COUPLED WITH A SHORTWAVE TROUGH MOVING INSIDE 130 W ON FRIDAY WILL
BUMP THE SHORTWAVE RIDGE AXIS EAST OF THE CASCADES BY MIDDAY FRIDAY.
FALLING HEIGHTS...INCREASING MID AND HIGH LEVEL CLOUDS...AND THE
ONSET OF STRONGER ONSHORE FLOW AHEAD OF A FRONTAL SYSTEM APPROACHING
THE COASTAL WATERS FRIDAY AFTERNOON MAY KEEP THE MAX TEMPS DOWN A
BIT OVER THURSDAY. A WEAK FRONT WILL MOVE ACROSS THE AREA LATE
FRIDAY NIGHT INTO SATURDAY MORNING. INCREASED ONSHORE FLOW COUPLED
WITH MID AND HIGH CLOUDS ASSOCIATED WITH THE PACIFIC SYSTEM WILL
LIKELY KEEP MOSTLY CLOUDY CONDITIONS IN PLACE SATURDAY. MODELS BRING
LIGHT PRECIPITATION TO THE COAST AND OLYMPICS SATURDAY MORNING. KEPT
LOW POPS IN THE FORECAST PACKAGE WITH SLIGHT CHANCE WORDING FOR THE
COAST.
.LONG TERM...MOIST ONSHORE FLOW AND COOL TEMPS WILL PERSIST INTO
SUNDAY. BOTH THE 12Z GFS AND ECMWF BRUSH A WEAK SHORTWAVE ONSHORE
SUNDAY MORNING...BRINGING SOME LIGHT PRECIPITATION MOSTLY TO THE
COAST AGAIN SUNDAY MORNING. THE GFS IS MUCH LIGHTER THAN THE
ECMWF... WITH THE LATTER BRINGING PRECIP INTO THE NORTHWEST
INTERIOR. LOOKS LIKE AT BEST THIS WILL BE DRIZZLE AND MAY BE HARD TO
MEASURE. FOR NOW LEFT SUNDAY MORNING DRY IN THE FORECAST PACKAGE.
THE ONSHORE GRADIENTS REMAIN STRONGER IN THE 12Z GFS VS THE
ECMWF...MAINTAINING A MORE PESSIMISTIC FORECAST FOR BREAK OUT DURING
THE AFTERNOON ON SUNDAY. TRENDED TOWARDS THE GFS IDEA WITH LITTLE
BREAK OUT SUNDAY NIGHT. UPPER LEVEL TROUGH OVER THE GULF OF ALASKA
AND NE PACIFIC SLOW TO MOVE OUT...DIGGING DOWN ALONG 130 W BY
MIDWEEK. EXPECT GENERALLY DRY WEATHER WITH MORNING CLOUDS AND
AFTERNOON SUNSHINE. SEASONAL TEMPERATURES.
&&
.AVIATION...UPPER TROUGH IN EASTERN WASHINGTON MOVING EAST WITH
HEIGHTS BUILDING OVER WESTERN WASHINGTON. LIGHT NORTHWESTERLY FLOW
ALOFT WITH ONSHORE SURFACE FLOW. AIR MASS STABLE. AREAS OF LOW LEVEL
MOISTURE WESTERN WASHINGTON EVAPORATING BY 02Z.
STRATUS HAS GONE FROM THE COAST AND STRAIT AND IS SLOWLY ERODING
AWAY OVER PUGET SOUND. NOW LOOKING FOR BREAKS IN THE OVERCAST BY 23Z
AND CLEARING BY 02Z. CEILINGS WILL RISE FROM 3K TO 5K FT DURING THIS
PERIOD. MAINLY CLEAR OVERNIGHT WITH POSSIBLY PATCHES OF STRATUS NEAR
MARINE AREAS.
KSEA...LOWER 3K FT CLOUD DECK SHOULD SCATTER OUT BY 23Z LEAVING A
BROKEN DECK AROUND 5K FT. CLEARING AFTER 02Z. WIND SW 6-10 KT
SWINGING AROUND TO NW BY 02Z...THEN LIGHT OVERNIGHT. CHB
&&
.MARINE...LOW LEVEL ONSHORE GRADIENTS DOWN THE STRAIT WILL BE ABOUT
THE SAME AGAIN TODAY AS TUE. SO W WINDS SHOULD REMAIN AT SMALL CRAFT
ADVISORY LEVELS. OTHERWISE..EXPECT FLOW WILL REMAIN ONSHORE THROUGH
FRIDAY WITH LIKELY SMALL CRAFT ADVISORY WINDS EACH EVENING IN THE
STRAIT. WILL NEED TO KEEP AN EYE ON THE STRAIT FOR POSSIBLE BRIEF
GALES AT TIMES.
A WEAKENING FRONT APPROACHING THE COAST FRIDAY NIGHT MAY BE STRONG
ENOUGH TO TURN WINDS SOUTHERLY ON THE COAST AND PERHAPS INLAND AS
WELL. FORECASTS REFLECT THIS TREND. MODELS ARE FAIRLY CONSISTENT
WITH THIS FEATURE AND HAVE ALSO BEEN CONSISTENT IN BRINGING A LITTLE
RAIN TO THE COAST AND OLYMPICS. WITH THE INCREASING SOUTHERLY FLOW
HAVE INDICATED THURSDAY NIGHT AS BEING THE TIME WITH THE LEAST
ONSHORE COMPONENT. CHB
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY CENTRAL AND EAST STRAIT.
$$
WEATHER.GOV/SEATTLE
000
FXUS66 KPQR 232145
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
245 PM PDT WED JUL 23 2008
.SYNOPSIS...AN UPPER LEVEL RIDGE WILL MOVE OVER THE PACIFIC NORTHWEST
TONIGHT AND CONTINUE OVER THE AREA THURSDAY FOR DRY AND A BIT WARMER
WEATHER. ANOTHER UPPER TROUGH WILL SET UP OFF THE COAST FOR FRIDAY
THROUGH EARLY NEXT WEEK WITH A SERIES A DISTURBANCES MOVING THROUGH.
THE MAIN EFFECT WILL BE TO INCREASE THE ONSHORE FLOW AGAIN.
HOWEVER...A WEAK FRONTAL BOUNDARY WILL MOVE ONTO THE COAST FRIDAY
NIGHT AND SATURDAY MORNING AND PRODUCE A LITTLE DRIZZLE ESPECIALLY
NEAR THE COAST. THERE IS NOT A LOT OF CHANGE IN THE MAIN PATTERN INTO
NEXT WEEK.
&&
.SHORT TERM...WATER VAPOR SATELLITE IMAGERY SHOWS THE MAIN IMPULSE
WITH THE CURRENT UPPER TROUGH IS MOSTLY EAST OF THE CASCADES THIS
AFTERNOON...WITH CLOUDS BREAKING UP ACROSS NORTHWEST OREGON FROM THE
SOUTH. THERE IS STILL A DECENT ONSHORE PUSH UP ALONG THE COLUMBIA
RIVER WHERE CLOUDS ARE MORE SOLID...BUT THESE TOO SHOULD BREAK UP IN
THE LATE AFTERNOON AND EARLY EVENING AND GENERALLY CLEAR OVERNIGHT.
WE WILL BE SEEING THE INVERSION REFORMING CLOSER TO THE SURFACE
OVERNIGHT AND SEE LOWER DECK OF STRATUS AND PATCHY FOG FORM TONIGHT
NEAR THE COAST AND POSSIBLY PUSH A BIT DOWN THE COLUMBIA RIVER EARLY
THURSDAY. BUT THEN THURSDAY SHOULD BE A NICE AND A BIT WARMER DAY
WITH MORE SUNSHINE AS THE UPPER RIDGE BEHIND THE EXITING SYSTEM IS
OVER THE AREA. INLAND TEMPS SHOULD MAKE IT TO NEAR OR A BIT OVER 80.
THE NEXT UPPER TROUGH APPROACHES THURSDAY NIGHT AND FRIDAY WITH
ONSHORE FLOW PICKING UP AGAIN LATE THURSDAY AND FRIDAY. NIGHT AND
MORNING LOW CLOUDS STILL LOOK AS THOUGH THEY WILL MAINLY PUSH THROUGH
THE COASTAL GAPS FRIDAY MORNING AND THEN CLEAR BACK TO NEAR THE COAST
IN THE AFTERNOON WITH INLAND TEMPS BACK DOWN A COUPLE OF DEGREES TO
NEAR NORMAL. THERE IS A WEAK FRONTAL BOUNDARY WITH THIS UPPER TROUGH
THAT TRIES TO PUSH TO NEAR THE COAST FRIDAY NIGHT AND SATURDAY AND
SHOULD INCREASE THE CLOUDS AT THE COAST AND EVEN INLAND WITH POSSIBLY
A LITTLE DRIZZLE AT THE COAST AND ALONG THE COASTAL MOUNTAINS. THE
CLOUDS MAY NOT CLEAR MUCH SATURDAY AFTERNOON EVEN INLAND. TOLLESON
.LONG TERM...THE UPPER TROUGH FROM LATE IN THE SHORT TERM PERIOD IS
STILL AROUND EARLY IN THE EXTENDED PERIOD...WITH A SHORT WAVE MOVING
THROUGH SATURDAY NIGHT THAT COULD PRODUCE A TOUCH OF DRIZZLE NEAR THE
NORTHERN MOUNTAINS. MAY SEE A BIT MORE SUNSHINE SUNDAY AFTERNOON
INLAND BUT TEMPS WILL BE TOUGH TO REACH NORMAL. HAVE LEFT THE
REMAINDER OF THE EXTENDED ALONE...WHICH REFLECTS NEAR NORMAL TEMPS
AND A MODERATE ONSHORE FLOW FOR LATE NIGHT AND MORNING LOW CLOUDS.
THE GFS MODEL LOOKS TOO STRONG ON A SYSTEM EARLY NEXT WEEK...WHILE
THE ECMWF IS MUCH WARMER...AND OPTED FOR A MIDDLE OF THE ROAD
SOLUTION THAT IS DRY BUT NEAR CLIMO. MAIN MESSAGE IS MODELS MAINTAIN
A WESTERLY FLOW ALOFT FOR A WHILE THAT ENCOURAGES SOME ONSHORE FLOW
WITH THE WEATHER NEAR NORMAL. TOLLESON
&&
.AVIATION...GENLY CLEAR INLAND WITH A FEW VFR CIGS IN THE EXTREME
NORTH PART OF THE AREA AND ALONG THE COAST. INLAND CLOUD COVER WILL
CONTINUE TO DISSIPATE THROUGH 03Z AND AFTER 08Z MVFR CIGS WILL MOVE
INLAND ALONG THE COLUMBIA RIVER REACHING KKLS ABOUT 12Z...AND TO KPDX
AROUND 15Z. AT THE COAST...VFR THROUGH ABOUT 03Z THEN LOWER MVFR CIGS
WILL BEGIN TO REFORM ALONG THE SHORE...WITH FAIRLY SOLID MVFR CIGS
AFTER 06Z.
KPDX AND APPROACHES...VFR CIGS WILL DISSIPATE BY 23Z...THEN VFR
CONDITIONS WILL PREVAIL THROUGH THE NIGHT. AFTER 14Z A FEW MVFR CIGS
MAY DEVELOP DUE TO MARINE STRATUS...BUT THEY WILL BURN OFF BY 17Z.
&&
.MARINE...HIGH PRESSURE OVER THE COASTAL WATERS WEAKENS SLIGHTLY THU
AS A WEAK FRONT APPROACHES FROM THE W. ON FRI THE HIGH WEAKENS
SIGNIFICANTLY AND SHIFTS EAST AS THE VERY WEAK FRONT MOVES OVER THE
COASTAL WATERS. HIGH PRES REBUILDS SAT AND ANOTHER FRONT APPROACHES
THE COASTAL WATERS LATE SUN. SEAS REMAIN BELOW 10 FT FOR THE
FORESEEABLE FUTURE. DK2
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR/WA...SMALL CRAFT ADVISORY FOR WINDS FROM CASCADE HEAD TO FLORENCE
THROUGH THIS EVENING.
&&
.PRELIMINARY POINT POPS (PROBABILITY OF MEASURABLE PRECIPITATION)
AST --1122 PDX 00---1 SLE 0000-1 EUG 0000--
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KOTX 232133
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
233 PM PDT WED JUL 23 2008
.SYNOPSIS...
A TROUGH WILL PASS ALONG THE CANADIAN BORDER OVER THE NEXT 12
HOURS...KEEPING THE THREAT OF ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS IN THE FORECAST. EXPECT A DRYING TREND THE REST OF THE
WORK WEEK.
&&
.DISCUSSION...
TONIGHT THROUGH FRIDAY NIGHT...UPPER LEVEL TROUGH WILL CONTINUE
ITS EASTWARD PROGRESSION ALONG THE US/CANADIAN BORDER THIS EVENING
AND OVERNIGHT. SCATTERED SHOWERS AND THUNDERSTORMS HAVE DEVELOPED
THIS AFTERNOON ACROSS THE NORTHEAST CASCADES EAST TOWARDS THE
OKANOGAN HIGHLANDS. AS THE TROUGH PUSHES EAST THROUGH THE
EVENING...SO WILL THE SHOWERS AND THUNDERSTORMS...EAST TOWARDS THE
NORTHEAST MOUNTAINS AND THE NORTH IDAHO PANHANDLE. NAM12 CAPE
VALUES OF AROUND 1000 J/KG AND LI`S OF -2 TO -3 C COUPLED WITH THE
WESTERLY STEERING FLOW FROM THE BASE OF THE TROUGH WILL KEEP
THUNDERSTORMS GOING TILL AROUND 11PM TONIGHT. THUNDERSTORMS WILL
CONTAIN BRIEF HEAVY RAIN AND SMALL HAIL ALONG WITH FREQUENT CLOUD TO
GROUND LIGHTNING. BY THURSDAY MORNING THE TROUGH WILL BE ALONG THE
WESTERN MONTANA/CANADIAN BORDER WITH A RIDGE REBUILDING ACROSS THE
WEST COAST. THE RIDGE WILL REMAIN OVER THE INLAND NORTHWEST
THROUGH FRIDAY FOR AN INCREASE IN TEMPERATURES EACH DAY RESULTING
IN TEMPERATURES RETURNING TO ABOVE AVERAGE READINGS FOR THIS TIME
OF THE YEAR. /NISBET
SATURDAY THROUGH WEDNESDAY...THE REGION WILL BE UNDER SOUTHWEST
FLOW ALOFT THROUGH MUCH OF THE EXTENDED PERIOD. ON SATURDAY THE
RIDGE AXIS WILL BE NUDGED EAST TO MONTANA. MID LEVEL HEIGHTS WILL
FALL AS A SHORTWAVE TROUGH MOVES THROUGH THE INLAND NORTHWEST
SATURDAY NIGHT AND SUNDAY. MOISTURE WILL BE LIMITED SO THE MAIN
EFFECT WILL BE COOLER TEMPERATURES AND AN INCREASE IN WINDS FOR
THE CASCADE GAPS DURING THE OVERNIGHT HOURS THROUGH THE WEEKEND.
THERE MAY BE A STRAY THUNDERSTORM ACROSS THE NORTHERN PANHANDLE OF
IDAHO SUNDAY AFTERNOON AS A VORT MAX CLIPS OUR NORTHEAST CORNER.
THE NEXT CHANCE OF PRECIPITATION WILL HOLD OFF UNTIL MIDWEEK WHEN
A TROUGH OF LOW PRESSURE APPROACHES THE PACIFIC NORTHWEST. THERE
IS A GOOD FETCH OF PRECIPITABLE WATER WITH THIS FEATURE BUT IT
APPEARS TO HAVE A DIFFICULT TIME GETTING PAST THE CASCADES. AT
THIS POINT THE FORECAST WILL REMAIN DRY. TEMPERATURES WILL CONTINUE
NEAR SEASONAL NORMALS THROUGH WEDNESDAY. /KELCH
&&
.AVIATION...
MAINLY VFR CONDITIONS EXPECTED AT ALL TAF SITES WITH AFTERNOON
CUMULUS DECKS OVER THE EASTERN COLUMBIA BASIN. AN UNSTABLE AND
MOIST AIR MASS WILL ALLOW THE DEVELOPMENT OF SCATTERED
THUNDERSTORMS ACROSS THE MOUNTAINS NORTH OF THE COLUMBIA BASIN
FROM 18Z TO 02Z TONIGHT...WITH THUNDERSTORMS DYING AFTER 05Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 53 83 58 92 62 87 / 10 0 0 0 0 0
COEUR D`ALENE 51 83 55 92 56 86 / 20 0 0 0 0 0
PULLMAN 45 83 49 92 53 86 / 0 0 0 0 0 0
LEWISTON 58 91 60 99 66 93 / 0 0 0 0 0 0
COLVILLE 47 87 50 94 55 90 / 50 0 0 0 0 0
SANDPOINT 48 81 49 89 55 84 / 50 0 0 0 0 0
KELLOGG 54 81 56 91 59 83 / 20 0 0 0 0 0
MOSES LAKE 53 89 58 94 60 91 / 0 0 0 0 0 0
WENATCHEE 60 89 63 94 65 88 / 0 0 0 0 0 0
OMAK 53 90 56 94 57 91 / 30 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
000
FXUS66 KOTX 231620 AAA
AFDOTX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SPOKANE WA
920 AM PDT WED JUL 23 2008
.SYNOPSIS...
A SERIES OF DISTURBANCES WILL PASS QUICKLY THROUGH THE PACIFIC
NORTHWEST THE NEXT 24 HOURS...KEEPING THE THREAT OF ISOLATED MOUNTAIN
SHOWERS IN THE FORECAST. EXPECT A DRYING TREND THE REST OF THE WORK
WEEK.
.UPDATE...
QUICK UPDATE TO INCREASE CLOUD COVER ACROSS THE EASTERN THIRD OF
THE COUNTY WARNING AREA FOR THIS MORNING. ALSO DECREASED MAX
TEMPERATURES AN ADDITIONAL 2-4 DEGREES FOR TODAY. UPPER LEVEL
TROUGH WILL MOVE ACROSS WASHINGTON TODAY AND TONIGHT. ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS STILL ANTICIPATED TO DEVELOP
THIS AFTERNOON AND EVENING ACROSS THE NORTHERN PORTION OF WA AND
ID. /NISBET
&&
PREV DISCUSSION... /ISSUED 430 AM PDT WED JUL 23 2008/
DISCUSSION...
TODAY... THE DEEP MONSOONAL PUSH AND ASSOCIATED YESTERDAYS WIDESPREAD
RAIN SHIELD OVER THE PANHANDLE HAS PUSHED WELL EAST OF THE
FORECAST AREA OVERNIGHT. THE MOISTURE FROM THIS SYSTEM HAS CREATED
SOME AREAS OF FOG AND LOW CLOUDS OVER THE IDAHO PANHANDLE AND
THESE AREAS WILL BREAK UP THIS MORNING AFTER SUNRISE. TODAY THE
REGION WILL BE INFLUENCED BY AN INCOMING PACIFIC SYSTEM...NOT
EASILY IDENTIFIABLE ON IR SAT...BUT READILY APPARENT AS AN
INCOMING WAVE ON THE WATER VAPOR IMAGERY. NAM AND GFS MODELS ARE
QUITE SIMILAR IN DEPICTING THIS SHORT WAVE TROUGH MOVING THROUGH
THE FORECAST AREA DURING THE DAY TODAY. THIS WILL PRODUCE A
COOLING ALOFT AND ASSOCIATED DECREASE IN STATIC
STABILITY...ESPECIALLY BY AFTERNOON WITH SURFACE HEATING
CONTRASTING THIS COOLING ALOFT. THIS WILL SET THE STAGE FOR
AFTERNOON AND EARLY EVENING THUNDERSTORMS MAINLY ACROSS THE
NORTHERN TEIR ZONES WHERE TROUGH CUSP DYNAMIC SUPPORT WILL FOCUS
IT`S ENERGY. OVER THE BASIN MAINLY DRY CONDITIONS WITH BROKEN
CUMULUS HIDING THE SUN FROM TIME TO TIME...WITH HIGH TEMPERATURES
A BIT BELOW NORMAL TODAY. ANOTHER MARINE SQUEEZE THROUGH CASCADES
GAPS THIS EVENING FOR ONCE AGAIN LOCALLY BREEZY CONDITIONS.
OVERNIGHT TONIGHT RIDGING ALOFT WILL ONCE AGAIN TAKE OVER AND
STABILIZE THE AIR MASS SOON AFTER SUNSET. AFTER EVENING CONVECTION
DIES DOWN...NO SIGNIFICANT WEATHER EXECTED WITH OVERNIGHT LOWS
NEAR SEASONAL AVERAGE. /FUGAZZI
THURSDAY THROUGH SATURDAY...THE MAIN PLAYER FOR THIS PORTION OF
THE FORECAST IS THE SYSTEM CURRENTLY REFLECTED ON WATER VAPOR
IMAGERY NEAR 150W OVER THE CENTRAL PACIFIC OCEAN. THE MID-LEVEL
REFLECTION OF THIS SYSTEM SEEMS TO BE WELL TRACKED BY THE MODELS.
ADDITIONALLY...MODEL AGREEMENT WITH FORWARD PHASE SPEED OF THE
SHORT WAVE TROUGH ASSOCIATED WITH THIS SYSTEM IS FAIRLY
GOOD...YIELDING AN ARRIVAL TIME OVER THE CWA OF ON OR ABOUT FRIDAY
NIGHT. WITH TIMING AS SUCH...THE CWA LOOKS TO BE UNDER INCREASING
WARM ADVECTION FROM THE BEGINNING OF THIS PORTION OF THE FORECAST
RIGHT THROUGH FRIDAY AFTERNOON. IN ADVANCE OF THE SHORT WAVE
ARRIVAL...500 MB HEIGHTS JUMP TOWARD 585 DAM OVER THE CWA...WITH
850 MB TEMPERATURES SURGING TO 24 TO 25C NEAR SPOKANE BY FRIDAY
AFTERNOON FROM ABOUT 19C ON THURSDAY MEANING A SURFACE TEMPERATURE
RISE WELL INTO THE 90S. HOWEVER...AS THE SYSTEM APPROACHES...MID-
LEVEL AND UPPER LEVEL MOISTURE GRADUALLY BEGINS TO
SURGE...RESULTING IN SOME SORT OF MID-LEVEL WEAKLY UNSTABLE CLOUD
FIELD FRIDAY NIGHT ACROSS THE AREA. INSTABILITY GENERATED FROM GFS
FIELDS SUGGESTS ONLY A SHALLOW LAYER OF INSTABILITY AROUND 500 MB
WITH DTHETA-E/DZ BARELY CRACKING THE 0C BARRIER. AS A RESULT...THE
FORECAST FEATURES ONLY AN INCREASE IN CLOUDS FRIDAY NIGHT ACROSS THE
EASTERN CWA...WITH ANY SIGNIFICANT WEATHER LEFT COMPLETELY OUT OF
THE EQUATION. WITH THE PASSING OF THE SHEARED OUT SHORT WAVE FRIDAY
NIGHT...MODEL HEIGHTS AND LAYER TEMPERATURES AGAIN SAG INTO THE
WEEKEND...RESULTING IN SOME COOLING BACK TOWARD NORMAL TEMPERATURES
AFTER FRIDAY...BUT CONTINUED VERY DRY CONDITIONS.
/FRIES
.AVIATION...
A MOIST LOW LEVEL AIR MASS WILL PROMOTE AREAS OF EARLY MORNING IFR
CEILINGS AND VIS IN THE VALLEYS OF NORTH IDAHO FROM 12Z TO 16Z. THIS
WILL MAINLY IMPACT THE KCOE TAF SITE WITH SOME SPILL OVER INTO THE
SPOKANE AREA. CONDITIONS WILL QUICKLY IMPROVE TO VFR AFTER 15 TO
16Z. OTHERWISE MAINLY VFR CONDITIONS EXPECTED AT ALL TAF SITES WITH
AFTERNOON CUMULUS DECKS OVER THE EASTERN COLUMBIA BASIN. AN UNSTABLE
AND MOIST AIR MASS WILL ALLOW THE DEVELOPMENT OF SCATTERED
THUNDERSTORMS ACROSS THE MOUNTAINS NORTH OF THE COLUMBIA BASIN FROM
18Z TO 02Z TONIGHT...WITH THUNDERSTORMS DYING AFTER SUNSET THIS
EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 76 54 84 58 92 63 / 10 10 0 0 0 0
COEUR D`ALENE 77 52 83 55 92 57 / 20 10 0 0 0 0
PULLMAN 77 45 83 49 92 54 / 30 10 0 0 0 0
LEWISTON 85 58 91 60 99 67 / 0 0 0 0 0 0
COLVILLE 79 47 87 50 94 55 / 30 50 0 0 0 0
SANDPOINT 75 48 81 49 89 56 / 20 20 0 0 0 0
KELLOGG 76 54 81 56 92 60 / 30 20 0 0 0 0
MOSES LAKE 85 53 89 58 94 62 / 0 0 0 0 0 0
WENATCHEE 84 60 89 63 94 67 / 0 0 0 0 0 0
OMAK 85 53 90 56 94 58 / 20 20 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
000
FXUS66 KSEW 231614
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
910 AM PDT WED JUL 23 2008
.SYNOPSIS...A WEAK UPPER LEVEL RIDGE WILL BEGIN TO SETTLE IN OVER
THE NORTHWEST TODAY. RISING HEIGHTS OVER WESTERN WASHINGTON COUPLED
WITH DRIER NORTHWEST FLOW WILL HELP ERODE THE MARINE LAYER AND
CLOUDS THIS AFTERNOON. SUNNY AND WARMER WEATHER WILL PERSIST UNDER
THE RIDGE THURSDAY AND FRIDAY. A WEAK FRONTAL SYSTEM MOVING INTO
WESTERN WASHINGTON EARLY SATURDAY WILL BRING INCREASED CLOUDINESS TO
THE AREA AND A CHANCE OF RAIN TO THE COAST. A SERIES OF WEAK UPPER
LEVEL SYSTEMS MOVING THROUGH THE PACIFIC NORTHWEST SUNDAY AND MONDAY
WILL KEEP CONDITIONS ON THE CLOUDY AND COOL SIDE INTO THE EARLY PART
OF NEXT WEEK.
&&
.SHORT TERM...BUILDING UPPER HEIGHTS AND WEAKER W/NW PRESSURE
GRADIENTS WILL HELP THE MARINE LAYER BREAK UP A BIT EARLIER
TODAY...BUMPING UP THE AFTERNOON TEMPS A BIT OVER YESTERDAY.
OVERNIGHT DRIER LOW LEVEL N/NW FLOW WILL HELP KEEP MARINE STRATUS
CONFINED TO THE COAST OVERNIGHT WITH MOST OTHER AREAS CLEAR. LACK OF
MORNING STRATUS OVER MOST INLAND AREAS AND BUILDING HIGH PRESSURE
OVER WESTERN WASHINGTON WILL GIVE TEMPS ANOTHER JUMP
THURSDAY...THOUGH NWLY FLOW WILL LIKELY ACT TO INHIBIT THE WARMER
VALUES SOMEWHAT. AREAS AWAY FROM THE WATER COULD REACH AROUND
80...WITH MID TO UPPER 70S ELSEWHERE. SUNNIER AND WARMER WEATHER
WILL CONTINUE INTO FRIDAY. FALLING HEIGHTS...INCREASING MID AND HIGH
LEVEL CLOUDS...AND THE ONSET OF STRONGER ONSHORE FLOW AHEAD OF A
FRONTAL SYSTEM APPROACHING THE COASTAL WATERS FRIDAY AFTERNOON MAY
KEEP THE MAX TEMPS DOWN A BIT OVER THURSDAY.
.LONG TERM...FROM PREVIOUS DISCUSSION...A TROUGH AND DECAYING FRONT
WILL MOVE ACROSS THE AREA FRIDAY NIGHT AND SETTLE OVER THE AREA
SATURDAY. ONSHORE FLOW WILL INCREASE...PERHAPS STRONG ENOUGH TO KEEP
MARINE CLOUDS SOCKED IN MUCH OF THE DAY. THE GFS NOW PAINTS SOME
LIGHT QPF W OF PUGET SOUND...PROBABLY IN THE FROM OF DRIZZLE. WILL
LEAVE THE LOW POPS IN FOR NOW. LOWER HEIGHTS...CLOUDS...AND COOL
TEMPS WILL PERSIST INTO SUNDAY. THE 00Z GFS IS MORE PESSIMISTIC ON
BREAK OUT DURING THE AFTERNOON BUT PREVIOUS RUNS WERE MORE
PROGRESSIVE WITH THE TROUGH WITH LESS ONSHORE FLOW. WILL KEEP A
TRANSITION TO PARTLY SUNNY IN THE FORECAST SUNDAY AFTERNOON FOR NOW.
HIGH PRESSURE BUILDS OVER THE INTERIOR WEST EARLY NEXT
WEEK...HOLDING THE NEXT LOW PRESSURE TROUGH JUST OFFSHORE. EXPECT
DRY WEATHER WITH THE TYPICAL MORNING CLOUDS AND AFTERNOON SUNSHINE
REGIME. TEMPS WILL REMAIN NEAR SEASONAL NORMS. MERCER
&&
.AVIATION...WEAK UPPER TROUGH OVER WESTERN WASHINGTON WILL MOVE EAST
OF THE CASCADES BY 00Z. SOUTHWEST FLOW ALOFT BECOMING NORTHWESTERLY
BEHIND THE TROUGH. HIGHER PRESSURE OFFSHORE AND LOWER PRESSURE EAST
OF THE CASCADES WILL KEEP SURFACE ONSHORE FLOW THROUGH THE END OF
THE WEEK. AIR MASS STABLE WITH AREAS OF MARINE STRATUS IN WESTERN
WASHINGTON EVAPORATING 20Z-00Z.
STRATUS COVERS MOST OF WESTERN WASHINGTON EAST TO THE CASCADE CREST.
SEVERAL LAYERS OF CLOUDS WITH LOWEST LAYER HAVING OCCASIONAL
CEILINGS 2.5K-3K FT AND HIGHEST LAYER TOPPING OUT AROUND 7K FT. HIGH
PRESSURE BUILDS SURFACE AND ALOFT TODAY AS UPPER TROUGH SHIFTS EAST.
THIS SHOULD BRING CONSIDERABLY MORE CLEARING THIS AFTERNOON THAN
YESTERDAY. ALREADY SEEING SOME THIN SPOTS IN STRAIT AND SOUTH PUGET
SOUND. BY 00Z SKIES SHOULD BE MOSTLY CLEAR.
KSEA...S OR SW WIND 6-10 KT TO PERSIST THROUGH THIS MORNING AND THEN
BEGIN SWINGING MORE WLY THIS AFTERNOON AND FROM THE N AFTER 00Z.
CEILINGS NEAR 3K FT THIS MORNING. THE LOWER LAYER SHOULD SCATTER OUT
BY 19Z...THE UPPER LAYER BY 22Z OR SO. CHB
&&
.MARINE...LOW LEVEL ONSHORE GRADIENTS DOWN THE STRAIT WILL BE ABOUT
THE SAME AGAIN TODAY AS TUE. SO W WINDS SHOULD REMAIN AT SMALL CRAFT
ADVISORY LEVELS. OTHERWISE..EXPECT FLOW WILL REMAIN ONSHORE THROUGH
FRIDAY WITH LIKELY SMALL CRAFT ADVISORY WINDS EACH EVENING IN THE
STRAIT. WILL NEED TO KEEP AN EYE ON THE STRAIT FOR POSSIBLE BRIEF
GALES AT TIMES.
A WEAKENING FRONT APPROACHING THE COAST FRIDAY NIGHT MAY BE STRONG
ENOUGH TO TURN WINDS SOUTHERLY ON THE COAST AND PERHAPS INLAND AS
WELL. FORECASTS REFLECT THIS TREND. WILL NEED TO MONITOR THE
PROGRESS AND EVOLUTION OF THIS FRONT IN CASE IT DIES OUT AS PREVIOUS
ONES HAVE DONE. CHB
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY CENTRAL AND EAST STRAIT.
$$
WEATHER.GOV/SEATTLE
000
FXUS66 KPQR 231557
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
857 AM PDT WED JUL 23 2008
.SYNOPSIS...AN UPPER LEVEL TROUGH WILL PASS BY TO THE EAST TODAY
THROUGH SOUTHWEST WASHINGTON AND NORTHWEST OREGON...MAINTAINING AN
ONSHORE FLOW EARLY THAT WILL WEAKEN LATE TODAY AND TONIGHT AS A WEAK
UPPER RIDGE MOVES OVER THE AREA. ANOTHER UPPER TROUGH WILL APPROACH
THE COAST THURSDAY NIGHT THAT WILL REMAIN NEAR OR OVER THE PACIFIC
NORTHWEST FRIDAY THROUGH THE WEEKEND AS A SERIES OF DISTURBANCES
ROTATES THROUGH THE TROUGH AND THROUGH OUR AREA. THE MAIN EFFECT WILL
BE TO STRENGTHEN THE ONSHORE FLOW AGAIN...WITH POSSIBLY A BIT OF
DRIZZLE AT TIMES ESPECIALLY NEAR THE COAST. NOT A LOT OF CHANGE IN
THE MAIN PATTERN INTO NEXT WEEK.
&&
.SHORT TERM...WATER VAPOR SATELLITE IMAGERY SHOWS THE MAIN IMPULSE
WITH THE CURRENT UPPER TROUGH IS MOVING THROUGH OUR AREA THIS MORNING
AND INTO CENTRAL AND EASTERN OREGON AND WASHINGTON. THIS HAS
MAINTAINED STRONG ONSHORE FLOW IN THE NORTH BUT WEAKER FLOW IN THE
SOUTH PART OF OUR FORECAST AREA WHERE CLOUDS ARE MORE BROKEN UP. THE
MAIN UPPER JET HAS MOVED EAST AND AM REMOVING ANY DRIZZLE FROM THE
MORNING UPDATE. THE SYSTEM IS EAST OF OUR AREA IN THE AFTERNOON AND
CLOUDS SHOULD CLEAR FROM THE SOUTH IN THE AFTERNOON AND EVENING...
THOUGH HANG ON NEAR THE NORTHERN MOUNTAINS FOR A WHILE INTO THE
EVENING AS THE WEST DUE TO THE WESTERLY PUSH BEHIND THE EXITING
SYSTEM. WHILE CLOUDS CONTINUE TO DISSIPATE OVERNIGHT...WILL SEE THE
INVERSION REFORM CLOSER TO THE SURFACE OVERNIGHT AND SEE LOWER DECK
OF STRATUS AND PATCHY FOG FORM TONIGHT NEAR THE COAST AND POSSIBLY
PUSH A BIT DOWN THE COLUMBIA RIVER EARLY THURSDAY. BUT THEN THURSDAY
SHOULD BE A NICE AND BIT WARMER DAY WITH MORE SUNSHINE AS A WEAK
UPPER RIDGE IS OVER THE AREA.
THE NEXT UPPER TROUGH APPROACHES THURSDAY NIGHT AND FRIDAY WITH
ONSHORE FLOW PICKING UP AGAIN. NIGHT AND MORNING LOW CLOUDS STILL
LOOK AS THOUGH THEY WILL MAINLY PUSH THROUGH THE COASTAL GAPS IN THE
MORNING AND THEN CLEAR IN THE AFTERNOON WITH NEAR NORMAL TEMPS. THERE
IS A WEAK FRONTAL BOUNDARY WITH THIS TROUGH THAT TRIES TO PUSH TO
NEAR THE COAST OVER THE WEEKEND AND SHOULD INCREASE THE CLOUDS AT THE
COAST AND EVEN INLAND WITH POSSIBLY A LITTLE DRIZZLE AT THE COAST.
MAY WAIT FOR ANY WEEKEND CHANGES UNTIL THE AFTERNOON PACKAGE.
TOLLESON
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MORNING CLOUDS...AFTERNOON SUN AND NIGHTTIME MARINE PUSHES WILL BE
THE STORY FOR THE EXTENDED. AN UPPER LEVEL DISTURBANCE WILL SWING
THROUGH ON FRIDAY EVENING...REINFORCING THE MARINE LAYER AND POSSIBLY
PROVIDING A LITTLE PATCHY DRIZZLE TO THE NORTHERN COASTAL ZONES.
UPPER HEIGHTS DO NOT RISE MUCH OVER THE WEEKEND SO NO SIGNIFICANT
WARM UP APPEARS TO BE IN THE MAKING THERE. ANOTHER TROUGH IS SLATED
FOR EARLY NEXT WEEK.
&&
.AVIATION...VFR CIGS IN MARINE CLOUDS COVER MOST OF THE AREA THIS
MORNING. A FEW MVFR CIGS ARE POSSIBLE AT THE COAST TODAY ESPECIALLY
THIS MORNING. INLAND BKN LAYERS WILL BECOME SCT-SKC AROUND BTWN 17
AND 21Z...IN THE SOUTH VALLEY FIRST AND LATEST IN THE NORTH.
KPDX AND APPROACHES...GENLY VFR THROUGHOUT THE DAY. SOME SLIGHT
POTENTIAL FOR HIGH END MVFR CIGS THROUGH ABOUT 17Z.
&&
.MARINE...NORTHWEST FLOW ACROSS THE COASTAL WATERS FOR THE NEXT FEW
DAYS. WIND MAY REACH SCA CRITERIA FROM GUSTS THIS EVENING ON THE
CENTRAL COAST AS A LATE SEA BREEZE ENHANCES GRADIENT WINDS. EXPECT
NEARLY THE SAME SCENARIO THU. WINDS WILL SLACKEN A BIT FRI AS SFC
HIGH WEAKENS IN RESPONSE TO A WEAK TROUGH ALOFT APPROACHING THE PAC
NW COAST. DK2
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR/WA...SMALL CRAFT ADVISORY FOR WINDS FROM CASCADE HEAD TO FLORENCE
THIS AFTERNOON THROUGH EVENING.
&&
.PRELIMINARY POINT POPS (PROBABILITY OF MEASURABLE PRECIPITATION)
AST 1--11 PDX -00-- SLE 00000 EUG 00000
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KOTX 231528
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
828 AM PDT WED JUL 23 2008
.SYNOPSIS...
A SERIES OF DISTURBANCES WILL PASS QUICKLY THROUGH THE PACIFIC
NORTHWEST THE NEXT 24 HOURS...KEEPING THE THREAT OF ISOLATED MOUNTAIN
SHOWERS IN THE FORECAST. EXPECT A DRYING TREND THE REST OF THE WORK
WEEK.
&&
.UPDATE...
QUICK UPDATE TO INCREASE CLOUD COVER ACROSS THE EASTERN THIRD OF
THE COUNTY WARNING AREA FOR THIS MORNING. ALSO DECREASED MAX
TEMPERATURES AN ADDITIONAL 2-4 DEGREES FOR TODAY. UPPER LEVEL
TROUGH WILL MOVE ACROSS WASHINGTON TODAY AND TONIGHT. ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS STILL ANTICIPATED TO DEVELOP
THIS AFTERNOON AND EVENING ACROSS THE NORTHERN PORTION OF WA AND
ID. /NISBET
&&
.PREV DISCUSSION... /ISSUED 430 AM PDT WED JUL 23 2008/
SYNOPSIS...
A SERIES OF DISTURBANCES WILL PASS QUICKLY THROUGH THE PACIFIC
NORTHWEST THE NEXT 24 HOURS...KEEPING THE THREAT OF ISOLATED MOUNTAIN
SHOWERS IN THE FORECAST. EXPECT A DRYING TREND THE REST OF THE WORK
WEEK.
DISCUSSION...
TODAY... THE DEEP MONSOONAL PUSH AND ASSOCIATED YESTERDAYS WIDESPREAD
RAIN SHIELD OVER THE PANHANDLE HAS PUSHED WELL EAST OF THE
FORECAST AREA OVERNIGHT. THE MOISTURE FROM THIS SYSTEM HAS CREATED
SOME AREAS OF FOG AND LOW CLOUDS OVER THE IDAHO PANHANDLE AND
THESE AREAS WILL BREAK UP THIS MORNING AFTER SUNRISE. TODAY THE
REGION WILL BE INFLUENCED BY AN INCOMING PACIFIC SYSTEM...NOT
EASILY IDENTIFIABLE ON IR SAT...BUT READILY APPARENT AS AN
INCOMING WAVE ON THE WATER VAPOR IMAGERY. NAM AND GFS MODELS ARE
QUITE SIMILAR IN DEPICTING THIS SHORT WAVE TROUGH MOVING THROUGH
THE FORECAST AREA DURING THE DAY TODAY. THIS WILL PRODUCE A
COOLING ALOFT AND ASSOCIATED DECREASE IN STATIC
STABILITY...ESPECIALLY BY AFTERNOON WITH SURFACE HEATING
CONTRASTING THIS COOLING ALOFT. THIS WILL SET THE STAGE FOR
AFTERNOON AND EARLY EVENING THUNDERSTORMS MAINLY ACROSS THE
NORTHERN TEIR ZONES WHERE TROUGH CUSP DYNAMIC SUPPORT WILL FOCUS
IT`S ENERGY. OVER THE BASIN MAINLY DRY CONDITIONS WITH BROKEN
CUMULUS HIDING THE SUN FROM TIME TO TIME...WITH HIGH TEMPERATURES
A BIT BELOW NORMAL TODAY. ANOTHER MARINE SQUEEZE THROUGH CASCADES
GAPS THIS EVENING FOR ONCE AGAIN LOCALLY BREEZY CONDITIONS.
OVERNIGHT TONIGHT RIDGING ALOFT WILL ONCE AGAIN TAKE OVER AND
STABILIZE THE AIR MASS SOON AFTER SUNSET. AFTER EVENING CONVECTION
DIES DOWN...NO SIGNIFICANT WEATHER EXECTED WITH OVERNIGHT LOWS
NEAR SEASONAL AVERAGE. /FUGAZZI
THURSDAY THROUGH SATURDAY...THE MAIN PLAYER FOR THIS PORTION OF
THE FORECAST IS THE SYSTEM CURRENTLY REFLECTED ON WATER VAPOR
IMAGERY NEAR 150W OVER THE CENTRAL PACIFIC OCEAN. THE MID-LEVEL
REFLECTION OF THIS SYSTEM SEEMS TO BE WELL TRACKED BY THE MODELS.
ADDITIONALLY...MODEL AGREEMENT WITH FORWARD PHASE SPEED OF THE
SHORT WAVE TROUGH ASSOCIATED WITH THIS SYSTEM IS FAIRLY
GOOD...YIELDING AN ARRIVAL TIME OVER THE CWA OF ON OR ABOUT FRIDAY
NIGHT. WITH TIMING AS SUCH...THE CWA LOOKS TO BE UNDER INCREASING
WARM ADVECTION FROM THE BEGINNING OF THIS PORTION OF THE FORECAST
RIGHT THROUGH FRIDAY AFTERNOON. IN ADVANCE OF THE SHORT WAVE
ARRIVAL...500 MB HEIGHTS JUMP TOWARD 585 DAM OVER THE CWA...WITH
850 MB TEMPERATURES SURGING TO 24 TO 25C NEAR SPOKANE BY FRIDAY
AFTERNOON FROM ABOUT 19C ON THURSDAY MEANING A SURFACE TEMPERATURE
RISE WELL INTO THE 90S. HOWEVER...AS THE SYSTEM APPROACHES...MID-
LEVEL AND UPPER LEVEL MOISTURE GRADUALLY BEGINS TO
SURGE...RESULTING IN SOME SORT OF MID-LEVEL WEAKLY UNSTABLE CLOUD
FIELD FRIDAY NIGHT ACROSS THE AREA. INSTABILITY GENERATED FROM GFS
FIELDS SUGGESTS ONLY A SHALLOW LAYER OF INSTABILITY AROUND 500 MB
WITH DTHETA-E/DZ BARELY CRACKING THE 0C BARRIER. AS A RESULT...THE
FORECAST FEATURES ONLY AN INCREASE IN CLOUDS FRIDAY NIGHT ACROSS THE
EASTERN CWA...WITH ANY SIGNIFICANT WEATHER LEFT COMPLETELY OUT OF
THE EQUATION. WITH THE PASSING OF THE SHEARED OUT SHORT WAVE FRIDAY
NIGHT...MODEL HEIGHTS AND LAYER TEMPERATURES AGAIN SAG INTO THE
WEEKEND...RESULTING IN SOME COOLING BACK TOWARD NORMAL TEMPERATURES
AFTER FRIDAY...BUT CONTINUED VERY DRY CONDITIONS.
/FRIES
&&
.AVIATION...
A MOIST LOW LEVEL AIR MASS WILL PROMOTE AREAS OF EARLY MORNING IFR
CEILINGS AND VIS IN THE VALLEYS OF NORTH IDAHO FROM 12Z TO 16Z. THIS
WILL MAINLY IMPACT THE KCOE TAF SITE WITH SOME SPILL OVER INTO THE
SPOKANE AREA. CONDITIONS WILL QUICKLY IMPROVE TO VFR AFTER 15 TO
16Z. OTHERWISE MAINLY VFR CONDITIONS EXPECTED AT ALL TAF SITES WITH
AFTERNOON CUMULUS DECKS OVER THE EASTERN COLUMBIA BASIN. AN UNSTABLE
AND MOIST AIR MASS WILL ALLOW THE DEVELOPMENT OF SCATTERED
THUNDERSTORMS ACROSS THE MOUNTAINS NORTH OF THE COLUMBIA BASIN FROM
18Z TO 02Z TONIGHT...WITH THUNDERSTORMS DYING AFTER SUNSET THIS
EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 79 54 84 58 92 63 / 10 10 0 0 0 0
COEUR D`ALENE 79 52 83 55 92 57 / 20 10 0 0 0 0
PULLMAN 80 45 83 49 92 54 / 30 10 0 0 0 0
LEWISTON 87 58 91 60 99 67 / 0 0 0 0 0 0
COLVILLE 81 47 87 50 94 55 / 30 50 0 0 0 0
SANDPOINT 77 48 81 49 89 56 / 20 20 0 0 0 0
KELLOGG 76 54 81 56 92 60 / 30 20 0 0 0 0
MOSES LAKE 85 53 89 58 94 62 / 0 0 0 0 0 0
WENATCHEE 84 60 89 63 94 67 / 0 0 0 0 0 0
OMAK 87 53 90 56 94 58 / 20 20 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
000
FXUS66 KOTX 231136
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
430 AM PDT WED JUL 23 2008
.SYNOPSIS...
A SERIES OF DISTURBANCES WILL PASS QUICKLY THROUGH THE PACIFIC
NORTHWEST THE NEXT 24 HOURS...KEEPING THE THREAT OF ISOLATED MOUNTAIN
SHOWERS IN THE FORECAST. EXPECT A DRYING TREND THE REST OF THE WORK
WEEK.
&&
.DISCUSSION...
TODAY... THE DEEP MONSOONAL PUSH AND ASSOCIATED YESTERDAYS WIDESPREAD
RAIN SHIELD OVER THE PANHANDLE HAS PUSHED WELL EAST OF THE
FORECAST AREA OVERNIGHT. THE MOISTURE FROM THIS SYSTEM HAS CREATED
SOME AREAS OF FOG AND LOW CLOUDS OVER THE IDAHO PANHANDLE AND
THESE AREAS WILL BREAK UP THIS MORNING AFTER SUNRISE. TODAY THE
REGION WILL BE INFLUENCED BY AN INCOMING PACIFIC SYSTEM...NOT
EASILY IDENTIFIABLE ON IR SAT...BUT READILY APPARENT AS AN
INCOMING WAVE ON THE WATER VAPOR IMAGERY. NAM AND GFS MODELS ARE
QUITE SIMILAR IN DEPICTING THIS SHORT WAVE TROUGH MOVING THROUGH
THE FORECAST AREA DURING THE DAY TODAY. THIS WILL PRODUCE A
COOLING ALOFT AND ASSOCIATED DECREASE IN STATIC
STABILITY...ESPECIALLY BY AFTERNOON WITH SURFACE HEATING
CONTRASTING THIS COOLING ALOFT. THIS WILL SET THE STAGE FOR
AFTERNOON AND EARLY EVENING THUNDERSTORMS MAINLY ACROSS THE
NORTHERN TEIR ZONES WHERE TROUGH CUSP DYNAMIC SUPPORT WILL FOCUS
IT`S ENERGY. OVER THE BASIN MAINLY DRY CONDITIONS WITH BROKEN
CUMULUS HIDING THE SUN FROM TIME TO TIME...WITH HIGH TEMPERATURES
A BIT BELOW NORMAL TODAY. ANOTHER MARINE SQUEEZE THROUGH CASCADES
GAPS THIS EVENING FOR ONCE AGAIN LOCALLY BREEZY CONDITIONS.
OVERNIGHT TONIGHT RIDGING ALOFT WILL ONCE AGAIN TAKE OVER AND
STABILIZE THE AIR MASS SOON AFTER SUNSET. AFTER EVENING CONVECTION
DIES DOWN...NO SIGNIFICANT WEATHER EXECTED WITH OVERNIGHT LOWS
NEAR SEASONAL AVERAGE. /FUGAZZI
THURSDAY THROUGH SATURDAY...THE MAIN PLAYER FOR THIS PORTION OF
THE FORECAST IS THE SYSTEM CURRENTLY REFLECTED ON WATER VAPOR
IMAGERY NEAR 150W OVER THE CENTRAL PACIFIC OCEAN. THE MID-LEVEL
REFLECTION OF THIS SYSTEM SEEMS TO BE WELL TRACKED BY THE MODELS.
ADDITIONALLY...MODEL AGREEMENT WITH FORWARD PHASE SPEED OF THE
SHORT WAVE TROUGH ASSOCIATED WITH THIS SYSTEM IS FAIRLY
GOOD...YIELDING AN ARRIVAL TIME OVER THE CWA OF ON OR ABOUT FRIDAY
NIGHT. WITH TIMING AS SUCH...THE CWA LOOKS TO BE UNDER INCREASING
WARM ADVECTION FROM THE BEGINNING OF THIS PORTION OF THE FORECAST
RIGHT THROUGH FRIDAY AFTERNOON. IN ADVANCE OF THE SHORT WAVE
ARRIVAL...500 MB HEIGHTS JUMP TOWARD 585 DAM OVER THE CWA...WITH
850 MB TEMPERATURES SURGING TO 24 TO 25C NEAR SPOKANE BY FRIDAY
AFTERNOON FROM ABOUT 19C ON THURSDAY MEANING A SURFACE TEMPERATURE
RISE WELL INTO THE 90S. HOWEVER...AS THE SYSTEM APPROACHES...MID-
LEVEL AND UPPER LEVEL MOISTURE GRADUALLY BEGINS TO
SURGE...RESULTING IN SOME SORT OF MID-LEVEL WEAKLY UNSTABLE CLOUD
FIELD FRIDAY NIGHT ACROSS THE AREA. INSTABILITY GENERATED FROM GFS
FIELDS SUGGESTS ONLY A SHALLOW LAYER OF INSTABILITY AROUND 500 MB
WITH DTHETA-E/DZ BARELY CRACKING THE 0C BARRIER. AS A RESULT...THE
FORECAST FEATURES ONLY AN INCREASE IN CLOUDS FRIDAY NIGHT ACROSS THE
EASTERN CWA...WITH ANY SIGNIFICANT WEATHER LEFT COMPLETELY OUT OF
THE EQUATION. WITH THE PASSING OF THE SHEARED OUT SHORT WAVE FRIDAY
NIGHT...MODEL HEIGHTS AND LAYER TEMPERATURES AGAIN SAG INTO THE
WEEKEND...RESULTING IN SOME COOLING BACK TOWARD NORMAL TEMPERATURES
AFTER FRIDAY...BUT CONTINUED VERY DRY CONDITIONS.
/FRIES
&&
.AVIATION...
A MOIST LOW LEVEL AIR MASS WILL PROMOTE AREAS OF EARLY MORNING IFR
CEILINGS AND VIS IN THE VALLEYS OF NORTH IDAHO FROM 12Z TO 16Z. THIS
WILL MAINLY IMPACT THE KCOE TAF SITE WITH SOME SPILL OVER INTO THE
SPOKANE AREA. CONDITIONS WILL QUICKLY IMPROVE TO VFR AFTER 15 TO
16Z. OTHERWISE MAINLY VFR CONDITIONS EXPECTED AT ALL TAF SITES WITH
AFTERNOON CUMULUS DECKS OVER THE EASTERN COLUMBIA BASIN. AN UNSTABLE
AND MOIST AIR MASS WILL ALLOW THE DEVELOPMENT OF SCATTERED
THUNDERSTORMS ACROSS THE MOUNTAINS NORTH OF THE COLUMBIA BASIN FROM
18Z TO 02Z TONIGHT...WITH THUNDERSTORMS DYING AFTER SUNSET THIS
EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 79 54 84 58 92 63 / 10 10 0 0 0 0
COEUR D`ALENE 79 52 83 55 92 57 / 10 10 0 0 0 0
PULLMAN 80 45 83 49 92 54 / 10 10 0 0 0 0
LEWISTON 87 58 91 60 99 67 / 0 0 0 0 0 0
COLVILLE 81 47 87 50 94 55 / 50 50 0 0 0 0
SANDPOINT 77 48 81 49 89 56 / 20 20 0 0 0 0
KELLOGG 76 54 81 56 92 60 / 20 20 0 0 0 0
MOSES LAKE 85 53 89 58 94 62 / 0 0 0 0 0 0
WENATCHEE 84 60 89 63 94 67 / 0 0 0 0 0 0
OMAK 87 53 90 56 94 58 / 20 20 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
000
FXUS66 KSEW 231016
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PDT WED JUL 23 2008
.SYNOPSIS...ONSHORE FLOW WILL WEAKEN TODAY AS A WEAK UPPER LEVEL
RIDGE WILL BEGIN MOVING OVER THE AREA. DRIER NORTHWEST FLOW WILL
DEVELOP THIS AFTERNOON ALLOWING CLOUDS TO GRADUALLY DISSIPATE
THROUGH EVENING. WARMER AND SUNNIER WEATHER WILL PREVAIL UNDER THE
RIDGE THURSDAY INTO FRIDAY. A WEAK FRONT WILL PRODUCE CLOUDY SKIES
SATURDAY AND A CHANCE OF RAIN ON THE COAST. SEVERAL WEAK TROUGHS
WILL KEEP TEMPERATURES A LITTLE COOLER WITH LESS SUNSHINE SUNDAY AND
MONDAY.
&&
.SHORT TERM...STRATUS FILLED BACK IN ACROSS THE AREA OVERNIGHT
THOUGH ONSHORE GRADIENTS ARE NOT AS STRONG AS YESTERDAY. AFTER THE
UPPER TROUGH AXIS SHIFTS EWD THIS MORNING...UPPER HEIGHTS WILL BUILD
WITH WEAKER W/NW PRESSURE GRADIENTS DEVELOPING IN THE AFTERNOON.
THIS IS A DRIER REGIME FOR THE LOWER LEVELS BUT THE DEEP MARINE
LAYER WILL BE STUBBORN TO MIX. THE GFS IS MORE OPTIMISTIC WITH BREAK
OUT DURING THE AFTERNOON AND THE NAM KEEPS OVERCAST SKIES INTO THE
EVENING. WILL GO BETWEEN THE TWO AND INDICATE PARTLY SUNNY SKIES
LATE IN THE DAY. TEMPS SHOULD WARM A FEW DEGREES OVER YESTERDAY WITH
THE WEAKER ONSHORE GRADIENTS AND PERHAPS A BIT MORE SUN BREAKS.
DRY N/NW LOW LEVEL FLOW TONIGHT SHOULD KEEP LOW CLOUDS LARGELY
CONFINED TO THE COAST. MOST THE AREA SHOULD WAKE TO MOSTLY SUNNY
SKIES ON THURSDAY WITH HIGH PRESSURE BUILDING STRONGER OVER THE
AREA. TEMPS SHOULD REBOUND SEVERAL MORE DEGREES...THOUGH NW ONSHORE
FLOW WILL PROBABLY KEEP TEMPS SLIGHTLY BELOW THE POTENTIAL HIGHS.
AREAS AWAY FROM THE WATER COULD REACH AROUND 80...WITH MID TO UPPER
70S ELSEWHERE. THE CLEAR WEATHER WILL CONTINUE INTO FRIDAY...THOUGH
HEIGHTS WILL START TO COME DOWN IN THE AFTERNOON AS A TROUGH
APPROACHES. ONSHORE FLOW WILL PICK UP LATE IN THE DAY AHEAD OF THE
ASSOCIATED FRONT SO HIGH TEMPS ON FRIDAY WILL PROBABLY RUN A COUPLE
DEGREES COOLER.
.LONG TERM...A TROUGH AND DECAYING FRONT WILL MOVE ACROSS THE AREA
FRIDAY NIGHT AND SETTLE OVER THE AREA SATURDAY. ONSHORE FLOW WILL
INCREASE...PERHAPS STRONG ENOUGH TO KEEP MARINE CLOUDS SOCKED IN
MUCH OF THE DAY. THE GFS NOW PAINTS SOME LIGHT QPF W OF PUGET
SOUND...PROBABLY IN THE FROM OF DRIZZLE. WILL LEAVE THE LOW POPS IN
FOR NOW. LOWER HEIGHTS...CLOUDS...AND COOL TEMPS WILL PERSIST INTO
SUNDAY. THE 00Z GFS IS MORE PESSIMISTIC ON BREAK OUT DURING THE
AFTERNOON BUT PREVIOUS RUNS WERE MORE PROGRESSIVE WITH THE TROUGH
WITH LESS ONSHORE FLOW. WILL KEEP A TRANSITION TO PARTLY SUNNY IN
THE FORECAST SUNDAY AFTERNOON FOR NOW. HIGH PRESSURE BUILDS OVER THE
INTERIOR WEST EARLY NEXT WEEK...HOLDING THE NEXT LOW PRESSURE TROUGH
JUST OFFSHORE. EXPECT DRY WEATHER WITH THE TYPICAL MORNING CLOUDS
AND AFTERNOON SUNSHINE REGIME. TEMPS WILL REMAIN NEAR SEASONAL
NORMS. MERCER
&&
.AVIATION...WEAK UPPER TROF JUST OFF COAST TO MOVE INTO EASTERN WA
WED EVENING. SW FLOW ALOFT OVER WA BECOMING NWLY BEHIND THE TROF.
HIGHER PRES OFFSHORE AND LOWER PRES E OF THE CASCADES FOR W TO E
PRES GRADIENTS ACROSS WA. AIR MASS STABLE WITH AREAS OF MARINE
STRATUS IN WESTERN WA.
AS OF EARLY THIS MORNING..MARINE STRATUS STILL HAD SOME HOLES IN
WESTERN WA. YET IT SHOULD SOLIDIFY AND BLANKET NEARLY ALL OF WESTERN
WA BY 14Z. STRATUS TOPS BETWEEN 5 AND 6K FT. MOST CEILINGS ARE VFR
BUT EXPECT SOME AREAS TO DROP INTO THE MVFR CATEGORY 13Z-17Z.
AS UPPER TROF PASSES OVERHEAD WED..LOW LEVEL FLOW TURNS MORE NW AND
ONSHORE GRADIENTS WILL TURN MORE N TO S THAN PURE W TO E MEANING THE
MARINE STRATUS SHOULD BREAK OUT DURING THE AFTERNOON. THE CLOUDS
WILL LIKELY HANG UP IN THE CASCADES..BUT THE LOWLANDS SHOULD SCATTER
BY MID AFTERNOON.
KSEA...S OR SW WIND 6-10 KT TO PERSIST THROUGH THIS MORNING AND THEN
BEGIN SWINGING MORE WLY THIS AFTERNOON AND FROM THE N AFTER 00Z. PER
THE TAF..EXPECT THE LIKELIHOOD THAT CEILINGS WILL TEMPORARILY DROP
TO NEAR 015 13Z-17Z BEFORE LIFTING BY MIDDAY. BUEHNER
&&
.MARINE...LOW LEVEL W TO E ONSHORE GRADIENTS DOWN THE STRAIT WILL BE
ABOUT THE SAME AGAIN TODAY AS TUE. SO W WINDS SHOULD REMAIN AT SMALL
CRAFT ADVISORY LEVELS. OTHERWISE..EXPECT FLOW WILL REMAIN ONSHORE
THROUGH FRIDAY WITH LIKELY SMALL CRAFT ADVISORY WINDS EACH EVENING
IN THE STRAIT. WILL NEED TO KEEP AN EYE ON THE STRAIT FOR POSSIBLE
BRIEF GALES AT TIMES.
A WEAKENING FRONT APPROACHING THE COAST FRIDAY NIGHT MAY BE STRONG
ENOUGH TO TURN WINDS SOUTHERLY ON THE COAST AND PERHAPS INLAND AS
WELL. DIGITAL FORECASTS REFLECT THIS TREND. WILL NEED TO MONITOR THE
PROGRESS AND EVOLUTION OF THIS FRONT IN CASE IT DIES OUT AS PREVIOUS
ONES HAVE DONE. BUEHNER
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY CENTRAL AND EAST STRAIT.
$$
000
FXUS66 KPQR 230944
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
243 AM PDT WED JUL 23 2008
.SYNOPSIS...A WESTERLY FLOW ALOFT OFF THE PACIFIC WILL BRING A SERIES
OF WEAK SHORTWAVE TROUGHS ACROSS THE PACIFIC NORTHWEST FOR THE
REMAINDER OF THE WEEK. THIS WILL KEEP THE LOW LEVEL FLOW ONSHORE...
KEEPING THE AIR MASS TEMPERATE WITH PERIODIC INTRUSIONS OF MARINE
MOISTURE INLAND THROUGH THE WEEKEND.
&&
.SHORT TERM...SATELLITE SHOWS PLENTY OF MARINE CLOUDS LINGERING INTO
THE EARLY MORNING...ESP ALONG THE CASCADES AND ON THE N COAST. EXPECT
CLOUDS TO FILL IN/REMAIN THROUGH THE MORNING AGAIN TODAY...SUPPORTED
BY SHORT WAVE MOVING ACROSS THIS MORNING. WEAK RIDGING BEHIND THE
TROUGH THIS AFTERNOON...AS WELL AS A SLOW SHIFT TO MORE NORTHERLY
WINDS IN LOW LEVELS WILL AID IN BREAKING UP CLOUDS BETTER THIS
AFTERNOON COMPARED WITH YESTERDAY. TODAY AND THU WILL SEE TEMPS
PROGRESSIVELY WARM IN RESPONSE TO BUILDING UPPER HEIGHTS. NEXT TROUGH
IN THE WESTERLY FLOW ALOFT ARRIVES FRI...COOLING AIR MASS A FEW
DEGREES.
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MORNING CLOUDS...AFTERNOON SUN AND NIGHTTIME MARINE PUSHES WILL BE
THE STORY FOR THE EXTENDED. AN UPPER LEVEL DISTURBANCE WILL SWING
THROUGH ON FRIDAY EVENING...REINFORCING THE MARINE LAYER AND POSSIBLY
PROVIDING A LITTLE PATCHY DRIZZLE TO THE NORTHERN COASTAL ZONES.
UPPER HEIGHTS DO NOT RISE MUCH OVER THE WEEKEND SO NO SIGNIFICANT
WARM UP APPEARS TO BE IN THE MAKING THERE. ANOTHER TROUGH IS SLATED
FOR EARLY NEXT WEEK.
&&
.AVIATION...VFR CLOUD DECK HAS BECOME FAIRLY WIDESPREAD ACROSS THE
DISTRICT EARLY THIS MORNING. EXPECT AREAS MVFR TO DEVELOP TOWARD
DAYBREAK WITH POSSIBLE LOCAL IFR CONDS IN DZ/BR ALONG THE COAST.
CIGS EXPECTED TO LIFT TO VFR AND/OR SCATTER OUT AROUND MIDDAY
INLAND...EARLY AFTERNOON ALONG THE COAST.
KPDX AND APPROACHES...VFR CIGS OCCASIONALLY DROPPING TO HIGH MVFR
THIS MORNING. BEST CHANCE OF MVFR CIGS WILL BE 12Z-18Z. OTHERWISE
EXPECT VFR WITH GUSTY W-NW AFTERNOON WINDS DEVELOPING ON KPDX
APPROACH. WEAGLE
&&
.MARINE...LIGHT TO MODERATE N-NW WINDS EXPECTED TODAY...EXCEPT FOR
LOCAL AFTERNOON GUSTS 20-25 KT ALONG THE CENTRAL OREGON COAST. WIND
SLIGHTLY STRONGER THU AS HIGH PRESSURE BUILDS OFFSHORE AND THERMAL
TROUGH STRENGTHENS INLAND...BUT FOR NOW FCST REMAINS BELOW SCA
CRITERIA. SERIES OF WEAK UPPER LEVEL DISTURBANCES SHOULD EASE N-NW
FLOW FRI AND SAT...OCCASIONALLY BACKING TO W-SW ACROSS THE NORTHERN
WATERS. SEAS TO REMAIN BELOW 10 FT THROUGH THE END OF THE WEEK.
WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR/WA...NONE.
&&
.PRELIMINARY POINT POPS (PROBABILITY OF MEASURABLE PRECIPITATION)
AST 1--00 PDX -0000 SLE 00000 EUG 00000
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KOTX 230920
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
220 AM PDT WED JUL 23 2008
.SYNOPSIS...
A SERIES OF DISTURBANCES WILL PASS QUICKLY THROUGH THE PACIFIC NORTHWEST
THE NEXT 24 HOURS...KEEPING THE THREAT OF ISOLATED MOUNTAIN
SHOWERS IN THE FORECAST. EXPECT A DRYING TREND THE REST OF THE
WORK WEEK.
&&
.DISCUSSION...
TODAY... THE DEEP MONSOONAL PUSH AND ASSOCIATED YESTERDAYS WIDESPREAD
RAIN SHIELD OVER THE PANHANDLE HAS PUSHED WELL EAST OF THE
FORECAST AREA OVERNIGHT. THE MOISTURE FROM THIS SYSTEM HAS CREATED
SOME AREAS OF FOG AND LOW CLOUDS OVER THE IDAHO PANHANDLE AND
THESE AREAS WILL BREAK UP THIS MORNING AFTER SUNRISE. TODAY THE
REGION WILL BE INFLUENCED BY AN INCOMING PACIFIC SYSTEM...NOT
EASILY IDENTIFIABLE ON IR SAT...BUT READILY APPARENT AS AN
INCOMING WAVE ON THE WATER VAPOR IMAGERY. NAM AND GFS MODELS ARE
QUITE SIMILAR IN DEPICTING THIS SHORT WAVE TROUGH MOVING THROUGH
THE FORECAST AREA DURING THE DAY TODAY. THIS WILL PRODUCE A
COOLING ALOFT AND ASSOCIATED DECREASE IN STATIC
STABILITY...ESPECIALLY BY AFTERNOON WITH SURFACE HEATING
CONTRASTING THIS COOLING ALOFT. THIS WILL SET THE STAGE FOR
AFTERNOON AND EARLY EVENING THUNDERSTORMS MAINLY ACROSS THE
NORTHERN TEIR ZONES WHERE TROUGH CUSP DYNAMIC SUPPORT WILL FOCUS
IT`S ENERGY. OVER THE BASIN MAINLY DRY CONDITIONS WITH BROKEN
CUMULUS HIDING THE SUN FROM TIME TO TIME...WITH HIGH TEMPERATURES
A BIT BELOW NORMAL TODAY. ANOTHER MARINE SQUEEZE THROUGH CASCADES
GAPS THIS EVENING FOR ONCE AGAIN LOCALLY BREEZY CONDITIONS.
OVERNIGHT TONIGHT RIDGING ALOFT WILL ONCE AGAIN TAKE OVER AND
STABILIZE THE AIR MASS SOON AFTER SUNSET. AFTER EVENING CONVECTION
DIES DOWN...NO SIGNIFICANT WEATHER EXECTED WITH OVERNIGHT LOWS
NEAR SEASONAL AVERAGE. /FUGAZZI
THURSDAY THROUGH SATURDAY...THE MAIN PLAYER FOR THIS PORTION OF
THE FORECAST IS THE SYSTEM CURRENTLY REFLECTED ON WATER VAPOR
IMAGERY NEAR 150W OVER THE CENTRAL PACIFIC OCEAN. THE MID-LEVEL
REFLECTION OF THIS SYSTEM SEEMS TO BE WELL TRACKED BY THE MODELS.
ADDITIONALLY...MODEL AGREEMENT WITH FORWARD PHASE SPEED OF THE
SHORT WAVE TROUGH ASSOCIATED WITH THIS SYSTEM IS FAIRLY
GOOD...YIELDING AN ARRIVAL TIME OVER THE CWA OF ON OR ABOUT FRIDAY
NIGHT. WITH TIMING AS SUCH...THE CWA LOOKS TO BE UNDER INCREASING
WARM ADVECTION FROM THE BEGINNING OF THIS PORTION OF THE FORECAST
RIGHT THROUGH FRIDAY AFTERNOON. IN ADVANCE OF THE SHORT WAVE
ARRIVAL...500 MB HEIGHTS JUMP TOWARD 585 DAM OVER THE CWA...WITH
850 MB TEMPERATURES SURGING TO 24 TO 25C NEAR SPOKANE BY FRIDAY
AFTERNOON FROM ABOUT 19C ON THURSDAY MEANING A SURFACE TEMPERATURE
RISE WELL INTO THE 90S. HOWEVER...AS THE SYSTEM APPROACHES...MID-
LEVEL AND UPPER LEVEL MOISTURE GRADUALLY BEGINS TO
SURGE...RESULTING IN SOME SORT OF MID-LEVEL WEAKLY UNSTABLE CLOUD
FIELD FRIDAY NIGHT ACROSS THE AREA. INSTABILITY GENERATED FROM GFS
FIELDS SUGGESTS ONLY A SHALLOW LAYER OF INSTABILITY AROUND 500 MB WITH
DTHETA-E/DZ BARELY CRACKING THE 0C BARRIER. AS A RESULT...THE
FORECAST FEATURES ONLY AN INCREASE IN CLOUDS FRIDAY NIGHT ACROSS
THE EASTERN CWA...WITH ANY SIGNIFICANT WEATHER LEFT COMPLETELY OUT
OF THE EQUATION. WITH THE PASSING OF THE SHEARED OUT SHORT WAVE
FRIDAY NIGHT...MODEL HEIGHTS AND LAYER TEMPERATURES AGAIN SAG INTO
THE WEEKEND...RESULTING IN SOME COOLING BACK TOWARD NORMAL
TEMPERATURES AFTER FRIDAY...BUT CONTINUED VERY DRY CONDITIONS.
/FRIES
&&
.AVIATION...
INTERMITTENT MVFR CEILINGS AND VISIBILITIES WILL CLEAR THE COEUR
D`ALENE...LEWISTON AND SPOKANE VALLEY TERMINALS BY 07Z. MOUNTAIN
OBSCURATIONS OVER THE CENTRAL AND SOUTHERN IDAHO PANHANDLE WILL BE
POSSIBLE THROUGH 9Z...WITH CLOUD BASES AS LOW AS 5-7KFT ABOVE SEA
LEVEL. THERE IS A CHANCE OF STRATUS AND/OR FOG FROM KLWS N TO
KPUW AND SPOKANE OVERNIGHT AFTER THE RAIN PULLS OUT...BUT WARM
GROUND TEMPERATURES AND MIXING JUST ABOVE THE BOUNDARY LAYER WILL
PROBABLY PRECLUDE ANY WIDESPREAD FOG DEVELOPMENT. BZ
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 79 54 84 58 92 63 / 10 10 0 0 0 0
COEUR D`ALENE 79 52 83 55 92 57 / 10 10 0 0 0 0
PULLMAN 80 45 83 49 92 54 / 10 10 0 0 0 0
LEWISTON 87 58 91 60 99 67 / 0 0 0 0 0 0
COLVILLE 81 47 87 50 94 55 / 50 50 0 0 0 0
SANDPOINT 77 48 81 49 89 56 / 20 20 0 0 0 0
KELLOGG 76 54 81 56 92 60 / 20 20 0 0 0 0
MOSES LAKE 85 53 89 58 94 62 / 0 0 0 0 0 0
WENATCHEE 84 60 89 63 94 67 / 0 0 0 0 0 0
OMAK 87 53 90 56 94 58 / 20 20 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
000
FXUS66 KOTX 230455
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
955 PM PDT TUE JUL 22 2008
.SYNOPSIS...
A SERIES OF DISTURBANCES WILL PASS QUICKLY THROUGH THE PACIFIC NORTHWEST
THE NEXT 24 HOURS...KEEPING THE THREAT OF ISOLATED MOUNTAIN
SHOWERS IN THE FORECAST. EXPECT A DRYING TREND THE REST OF THE
WORK WEEK.
&&
.DISCUSSION...THE RAPIDLY-FILLING SHORT-WAVE TROF THAT HELPED TO
PRODUCE PCPN AMNTS UP TO ONE-QUARTER INCH FOR A NUMBER OF TOWNS
ACROSS FAR ERN WA AND N ID ID HAS MOVED FAR ENOUGH INTO WRN MT ALREADY
THAT IT WON`T BE A MAJOR PLAYER IN THE FCST FOR THE REST OF THE
NIGHT. THE PCPN AMNTS MENTIONED ABOVE...HOWEVER...WILL BE AN ISSUE
GIVEN THE RAPIDLY CLEARING SKIES IN THE PRESENCE OF LG- SCALE
SUBSIDENCE ALOFT ON THE BACK SIDE OF THE SHORT-WAVE. THESE
CONDITIONS WILL COMBINE WITH LIGHT WINDS TO PRODUCE AN INCREASING
THREAT OF STRATUS AND/OR FOG FOR ALL THE VALLEYS OF EXTREME NE WA
AND MUCH OF ID. TO THE WEST...THE TIGHT TEMP/PRESSURE GRADIENT
ACROSS THE CASCADES SHOULD CONTINUE TO WEAKEN AND THE CURRENTLY
GUSTY WEST WINDS NEAR THE E SLOPES OF TE CASCADES AND WRN BASIN
SHOULD DECREASE STEADILY THE REST OF THE NIGHT. WE`LL KEEP AN
ISOLATED MENTION OF MTN SHOWERS IN THE FCST FOR THE WA/BC BORDER N
OF REPUBLIC THE NEXT FEW HRS...AS WELL AS CABINET GORGE TO
EASTPORT. THE NEXT FAST-APPROACHING VORT MAX...NOW NEARLY OVER THE
PAC NW COAST...WILL PRODUCE ANOTHER ROUND OF LIFT AFTER 6Z OVER ERN
WA. HOWEVER THIS WAVE IS ACTING ON A DRY AIR-MASS ALOFT...WITH
ONLY A FEW CLOUDS EXPECTED THE REST OF THE NT...MOST LIKELY
CLOSE TO THE BC/WA BORDER WHERE THE CURRENT SHOWERS ARE MOVING
SLOWLY N ON RADAR. BZ
&&
.AVIATION...
INTERMITTENT MVFR CEILINGS AND VISIBILITIES WILL CLEAR THE COEUR
D`ALENE...LEWISTON AND SPOKANE VALLEY TERMINALS BY 07Z. MOUNTAIN
OBSCURATIONS OVER THE CENTRAL AND SOUTHERN IDAHO PANHANDLE WILL BE
POSSIBLE THROUGH 9Z...WITH CLOUD BASES AS LOW AS 5-7KFT ABOVE SEA
LEVEL. THERE IS A CHANCE OF STRATUS AND/OR FOG FROM KLWS N TO
KPUW AND SPOKANE OVERNIGHT AFTER THE RAIN PULLS OUT...BUT WARM
GROUND TEMPERATURES AND MIXING JUST ABOVE THE BOUNDARY LAYER WILL
PROBABLY PRECLUDE ANY WIDESPREAD FOG DEVELOPMENT. BZ
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 53 79 54 88 57 92 / 0 10 0 0 0 0
COEUR D`ALENE 51 79 52 86 53 92 / 0 10 10 0 0 0
PULLMAN 51 80 45 87 48 90 / 0 10 0 0 0 0
LEWISTON 56 87 58 94 61 97 / 0 0 0 0 0 0
COLVILLE 51 81 47 90 48 95 / 0 20 20 0 0 0
SANDPOINT 54 77 48 83 47 87 / 10 20 10 0 0 0
KELLOGG 52 76 54 86 53 91 / 10 20 10 0 0 0
MOSES LAKE 60 85 53 92 57 94 / 0 0 0 0 0 0
WENATCHEE 60 84 60 91 62 93 / 0 0 0 0 0 0
OMAK 58 87 53 92 56 94 / 0 10 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
000
FXUS66 KPQR 230353
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
855 PM PDT TUE JUL 22 2008
.SYNOPSIS...NEXT UPPER TROUGH APPROACHING COAST MOVES ACROSS AREA
WEDNESDAY MORNING THEN MOVES INTO EASTERN OREGON DURING THE
AFTERNOON. ONSHORE FLOW CONTINUES TONIGHT AND WEDNESDAY WITH FLOW
BECOMING MORE NORTHWEST OVER SOUTH PART IN THE AFTERNOON. UPPER RIDGE
STRENGTHENS OVER PACIFIC NORTHWEST THURSDAY. MARINE AIR MASS MORE
SHALLOW WEDNESDAY NIGHT WITH QUICKER CLEARING BY MIDDAY THURSDAY.
SOUTHWEST FLOW ALOFT INCREASES THURSDAY NIGHT AND FRIDAY NEXT UPPER
TROUGH APPROACHES. MARINE AIR MASS STILL SHALLOW THURSDAY NIGHT AND
FRIDAY. ONSHORE FLOW INCREASES FRIDAY AS THERMAL TROUGH SHIFTS
TO EASTERN OREGON. WEAKENING FRONT DISSIPATES OVER NORTHERN COASTAL
AREA SATURDAY MORNING WITH MODERATE ONSHORE FLOW OVER THE AREA
SATURDAY AFTERNOON. ONSHORE FLOW STRONGER OVER AREA SUNDAY
DECREASES MONDAY.
&&
.SHORT TERM...MARINE CLOUDS FILLING IN OVER INTERIOR THIS EVE AFTER
BRIEF BREAK UP LATE THIS AFTERNOON. NEXT UPPER TROUGH APPROACHING
COAST WILL PUSH MARINE CLOUDS BACK SOLIDLY INTO COAST LATER TONIGHT.
WITH CLOUD COVER WILL BUMP TONIGHT TEMPS UP SOME. TROUGH WILL MOVE
ACROSS AREA WED MORNING BRINGING FAIRLY DEEP MARINE AMS OVER AREA.
WILL CONTINUE DRIZZLE THREAT NORTHERN COASTAL AREA AND SW WA LATE
TONIGHT AND WED MORNING WITH UPPER TROUGH. UPPER TROUGH OVER EASTERN
ORE WED AFTERNOON. STILL A FAIR AMOUNT OF ONSHORE FLOW WED ESPECIALLY
N PART. WILL SLOW CLEARING DOWN AND LEAVE N ONLY PS BY LATER
AFTERNOON WITH MOST CLEARING S. UPPER RIDGE STRENGTHENS OVER AREA WED
NIGHT WITH MARINE AMS MORE SHALLOW. MAIN INLAND PUSH BY THU MORNING
DOWN COL RIVER. UPPER RIDGE OVER CENTRAL AND EASTERN ORE THU WITH
THERMAL TROUGH OVER CENTRAL ORE. WARMER AMS OVER AREA WITH TEMPS BACK
TO NEAR NORMAL. SOUTHWEST FLOW ALOFT INCREASES OVER AREA THU NIGHT
AND FRI AS NEXT UPPER TROUGH APPROACHES. MARINE AMS STILL SHALLOW THU
NIGHT WITH SOME FOG PATCHES COAST AND COASTAL VALLEYS. ONSHORE FLOW
INCREASES FRI AS THERMAL TROUGH SHIFTS CLOSE TO IDA BORDER. MARINE
CLOUDS LIMITED FRI MORNING WITH SHALLOW MARINE AMS THOUGH HIGH LEVEL
CLOUDS SHOULD START INCREASING AS UPPER TROUGH APPROACHES. KOSOVITZ
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MORNING CLOUDS...AFTERNOON SUN AND NIGHTTIME MARINE
PUSHES WILL BE THE STORY FOR THE EXTENDED. AN UPPER LEVEL DISTURBANCE
WILL SWING THROUGH ON FRIDAY EVENING...REINFORCING THE MARINE LAYER
AND POSSIBLY PROVIDING A LITTLE PATCHY DRIZZLE TO THE NORTHERN
COASTAL ZONES. UPPER HEIGHTS DO NOT RISE MUCH OVER THE WEEKEND SO NO
SIGNIFICANT WARM UP APPEARS TO BE IN THE MAKING THERE. ANOTHER TROUGH
IS SLATED FOR EARLY NEXT WEEK.
&&
.AVIATION...VFR CEILINGS THIS EVENING IN PARTIALLY CLEARING SKIES
ACROSS AREAS OF THE FORECAST AREA WILL EVENTUALLY GIVE WAY TO A
RETURN OF MARINE STRATUS OVERNIGHT TONIGHT. EXPECT MVFR CIGS TO
RETURN TO MOST OF THE FORECAST AREA LATE TONIGHT AND CONTINUE
THROUGH LATE MORNING WED. A SHORTWAVE MOVING ACROSS THE AREA TONIGHT
INTO WED WILL ENHANCE ONSHORE FLOW THROUGH WED. MAY SEE CIGS AROUND
2500 FEET INLAND AND 1500 FEET AT THE COAST EARLY WED WITH A LITTLE
PATCHY DRIZZLE MAINLY NEAR THE COAST.
PDX AND APPROACHES...VFR CEILINGS WILL CONTINUE FOR A FEW MORE HOURS
TONIGHT BEFORE ONSHORE FLOW AGAIN BRINGS MARINE STRATUS TO KPDX AND
SURROUNDING AREAS. CIGS WILL LIKELY LOWER OVERNIGHT AND POSSIBLY
REACH 2500 TO 3000 FEET LATE TONIGHT AND WED MORNING...AND ARE
EXPECTED TO LIFT TO VFR AGAIN LATER WED AFTERNOON. BROWN
&&
.MARINE...ONSHORE FLOW WITH LITTLE ALONG SHORE COMPONENT AND PLENTY
OF CLOUDS WILL CONTINUE TO KEEP WINDS BELOW SMALL CRAFT LEVELS
TONIGHT. SEAS CURRENTLY AROUND 7 FT WILL EASE BACK DOWN A COUPLE OF
FEET TONIGHT AND WED. SURFACE HIGH PUSHES INLAND A BIT TO OUR NORTH
LATE WED AND WED EVENING AND MAY PUSH WINDS ON THE CENTRAL OREGON
COAST TO NEAR SMALL CRAFT LEVELS THEN...MAINLY IN LOCAL GUSTS NEAR
THE COAST AND SOUTH OF NEWPORT. BROWN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR/WA...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR THIS
EVENING.
&&
.PRELIMINARY POINT POPS (PROBABILITY OF MEASURABLE PRECIPITATION)
AST 11--00 PDX --0000 SLE 0-0000 EUG 000000
$$
MORE WEATHER INFORMATION ONLINE AT...
Http://weather.gov/portland
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KSEW 230352
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
852 PM PDT TUE JUL 22 2008
.SYNOPSIS...WEAK ONSHORE FLOW WILL CONTINUE TONIGHT KEEPING MARINE
MOISTURE OVER WESTERN WASHINGTON FOR CLOUDY SKIES INTO WEDNESDAY
AFTERNOON. A WEAK UPPER LEVEL RIDGE WILL BEGIN MOVING OVER THE AREA
WEDNESDAY AFTERNOON WITH DRIER NORTHWEST FLOW ALLOWING CLOUDS TO
GRADUALLY DISSIPATE THROUGH EVENING. WARMER AND SUNNIER WEATHER WILL
PREVAIL UNDER THE RIDGE THURSDAY WITH THE EFFECTS LASTING INTO
FRIDAY. A WEAK FRONT WILL PRODUCE CLOUDY SKIES SATURDAY AND A CHANCE
OF RAIN ON THE COAST. SEVERAL WEAK TROUGHS WILL KEEP TEMPERATURES A
LITTLE COOLER WITH LESS SUNSHINE SUNDAY AND MONDAY.
&&
.SHORT TERM...ONSHORE PRESSURE GRADIENTS ARE WEAKER THAN LAST
EVENING BUT THE CROSS CASCADE GRADIENT IS RUNNING JUST UNDER 10 MB.
LAST VISIBLE SATELLITE IMAGES SHOWED LOTS OF LOW LEVEL MOISTURE
STILL AROUND W WA IN A MARINE LAYER ABOUT 5000 FEET DEEP. CURRENT
CLEAR AREAS OVER THE SW INTERIOR...WHATCOM COUNTY...AND ALONG THE
STRAIT SHOULD FILL IN AS EXPECTED OVERNIGHT.
MAIN FORECAST PROBLEM IS FIGURING OUT HOW MUCH AND THE TIMING OF THE
CLEARING ON WEDNESDAY. 18Z GFS IS MUCH MORE OPTIMISTIC THAN THE 00Z
NAM. CURRENT FORECASTS SEEM TO BE A COMPROMISE BETWEEN THE TWO WITH
GRADUAL CLEARING EXPECTED TO TAKE PLACE THROUGH WEDNESDAY AFTERNOON.
WILL STICK WITH THAT IDEA THOUGH PER THE NAM THERE IS PROBABLY A
BETTER CHANCE OF MOSTLY CLOUDY CONTINUING THROUGH THE AFTERNOON.
EVEN WITH SLOWER DISSIPATION...THERE WILL PROBABLY BE BREAKS
DEVELOPING RIGHT OVER PUGET SOUND AND THE KITSAP PENINSULA DURING
THE AFTERNOON. NW FLOW AT 850 MB WILL HELP CLOUDS PILE UP AGAINST
THE CASCADES...KINDA DOOMING THE EAST PUGET SOUND LOWLANDS. THE
UPPER LEVEL TROUGH NEAR 130W APPROACHING THE AREA THIS EVENING WILL
MOVE EAST BY AFTERNOON...BUT TIME HEIGHT SECTIONS SHOW THE TROUGH
HAVING LITTLE OR NO IMPACT BELOW 700 MB.
A WEAK UPPER LEVEL RIDGE MOVES OVER THE AREA AS EXPECTED WEDNESDAY
NIGHT AND THURSDAY. WESTERLY ONSHORE FLOW WEDNESDAY EVENING SHOULD
PRODUCE AREAS OF SHALLOWER MORNING LOW CLOUDS...BUT THESE SHOULD
BURN OFF DURING THE MORNING FOR A MOSTLY SUNNY AND WARMER DAY. THE
RIDGE MOVES EAST THURSDAY EVENING BUT THE EFFECTS OF THE RIDGE
SHOULD LAST INTO FRIDAY SINCE THE NEXT UPPER LEVEL TROUGH DOESN`T
REACH THE AREA UNTIL FRIDAY NIGHT. KAM
.LONG TERM...PREVIOUS DISCUSSION FROM THE 3 PM AFD...THE UPPER
TROUGH AND WEAK FRONT DISCUSSED ABOVE WILL MOVE ACROSS WESTERN
WASHINGTON FRIDAY NIGHT AND SATURDAY. THIS FEATURE WILL KEEP THE
FORECAST AREA MOSTLY CLOUDY...AND I ADDED A CHANCE OF RAIN TO THE
OLYMPICS...COAST...AND COASTAL WATERS. PRECIPITATION FURTHER INLAND
IS NOT OUT OF THE QUESTION...BUT I THINK IT`S BEST TO LEAVE IT OUT
OF THE FORECAST AT THIS TIME.
FOR SUNDAY THROUGH TUESDAY THE LONGER RANGE MODELS CONTINUE TO SHOW
WEAK UPPER SYSTEMS MOVING THROUGH THE REGION...BUT THEY CONTINUE TO
DIFFER FROM RUN-TO-RUN AND BETWEEN MODELS. THE BOTTOM LINE WITH THIS
PATTERN WILL LIKELY BE A LITTLE STRONGER MARINE INFLUENCE THAN IS
TYPICAL FOR LATE JULY -- I.E. AREAS OF NIGHT AND MORNING CLOUDS...
PARTLY TO MOSTLY SUNNY AFTERNOONS AND EVENINGS...AND TEMPERATURES
JUST A LITTLE BELOW NORMAL. MCDONNAL
&&
.AVIATION...WEAK UPPER TROF JUST OFF COAST TO MOVE INTO WESTERN WA
WED. SW FLOW ALOFT OVER WA BECOMING WLY WED. HIGHER PRES OFFSHORE
AND LOWER PRES E OF THE CASCADES FOR W TO E PRES GRADIENTS ACROSS
WA. AIR MASS STABLE WITH AREAS OF MARINE STRATUS IN WESTERN WA.
LAST OF EVENING VISIBLE SATELLITE IMAGERY SHOWS A FEW BREAKS IN THE
MARINE STRATUS IN WESTERN WA. WITH ONSHORE FLOW..EXPECT THE MARINE
STRATUS TO FILL IN BY 14Z WED. TOPS OF STRATUS BETWEEN 5 AND 6K FT.
CEILINGS VARY FROM CLOSE TO 025 TO OVER 040. EXCEPT CEILINGS TO
GRADUALLY FALL INTO THE MVFR CATEGORY BY WED AM.
AS UPPER TROF PASSES OVERHEAD WED..LOW LEVEL FLOW TURNS MORE NW AND
ONSHORE GRADIENTS WILL TURN MORE N TO S THAN W TO E MEANING THE
STRATUS SHOULD BREAK OUT DURING THE AFTERNOON.
KSEA...S OR SW WIND 6-10 KT TO PERSIST THROUGH THE NIGHT AND WED AM.
SCATTERED TO BROKEN CLOUDS TO BECOME OVERCAST AGAIN BY 12Z WED.
BUEHNER
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY CENTRAL AND EAST STRAIT.
$$
000
FXUS66 KOTX 222340
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
440 PM PDT TUE JUL 22 2008
.SYNOPSIS...
A SERIES OF DISTURBANCES PASSING THROUGH THE PACIFIC NORTHWEST AND
INTERMOUNTAIN WEST TONIGHT INTO WEDNESDAY EVENING. RIDGING IN SOME
SHAPE OR FORM WILL TAKE HOLD FOR THE REMAINDER OF THE WEEK...THROUGH
THE WEEKEND...AND INTO THE EARLY PART OF NEXT WEEK.
&&
UPDATED AVIATION DISCUSSION
.DISCUSSION...
ISSUED 240 PM
TONIGHT THROUGH THURSDAY NIGHT...BETTER TO JUST LOOK AT
SATELLITE...RADAR...AND OBSERVATIONS THAN MODELS AS FAR AS HOW THE
SHORT TERM SCENARIO UNFOLDS. CLOSED LOW THAT WAS OFF THE
CALIFORNIA COAST YESTERDAY HAS EJECTED INLAND AND IS FIRING OFF
SIGNIFICANT CONVECTION AS IT FOLLOWS A PATH NORTHEAST THROUGH
OREGON AND SOUTHWEST IDAHO. LOTS OF CONVECTIVE DEBRIS CLOUD COVER
IN ADDITION TO THE CLOUDS COUPLED WITH SHOWERS WORKING THEIR WAY
NORTHEAST WILL CLUTTER THE SHORT TERM FORECAST TONIGHT WITH POPS
IN SOME SHAPE OR FORM. SOMEWHAT CLEARER SKIES TO THE NORTHWEST
NEAR THE EAST SLOPES OF THE CASCADES HAVE ALLOWED SURFACE BASED
CONVECTION TO FIRE OFF AND THUS MINOR DEPICTION OF
SHOWERS/THUNDERSTORMS REMAINS THERE THIS EVENING WHILE THE EARLIER
DISCUSSED CLOUD COVER SEEMS TO HAVE INHIBITED THUNDERSTORM
ACTIVITY OVER EXTREME EASTERN WASHINGTON AND NORTHERN IDAHO UP TO
NOW...AND IS EXPECTED TO CONTINUE TO DO SO. A COLD FRONT PASSAGE
WILL SEAL THE DEAL TONIGHT WITH ALL FEATURES TRANSLATING
NORTHEAST/EAST AND AWAY FROM THE FORECAST AREA BY TOMORROW.
ANOTHER SHORTWAVE...A SMALL LOW PRESSURE SYSTEM...IS EXPECTED TO
GLIDE THROUGH SOUTHERN BRITISH COLUMBIA WITHIN CLOSE PROXIMITY TO
THE BORDER AND ALLOW FOR THE POTENTIAL OF SURFACE BASED
AFTERNOON/EARLY EVENING CONVECTION WEDNESDAY. THIS TOO PASSES AND
ALLOWS FOR COMPLICATED RIDGING WITH A SOUTHWEST FLOW THAT FOR NOW IS
DEPICTED WITH LOW BUT NONZERO POPS FOR THURSDAY INTO THURSDAY NIGHT.
WARMING TREND QUITE VIVID IN COMPARISON TO THE COOL DAYTIME HIGHS
THAT HAVE AFFECTED MUCH OF THE DAY TODAY UP TO NOW. /PELATTI
FRIDAY THROUGH TUESDAY...THE LONGWAVE PATTERN OVER NORTH AMERICA
WILL CHANGE LITTLE DURING THE NEXT WEEK. A TROUGH OVER THE GULF OF
ALASKA AND A LARGE HIGH PRESSURE RIDGE OVER THE INTER-MOUNTAIN WEST
WILL PUT THE PACIFIC NORTHWEST IN A DRY SOUTHWEST FLOW THIS
WEEKEND INTO EARLY NEXT WEEK. FRIDAY WILL LIKELY BE THE WARMEST
IN THE NEXT 7 DAYS. 850MB TEMPERATURES OFF THE ECMWF AND GFS ARE
FORECAST TO BE BETWEEN 21-25C OVER EASTERN WASHINGTON AND NORTHERN
IDAHO. THE HOTTEST CONDITIONS SHOULD BE IN THE SOUTHEASTERN
PORTION OF THE FORECAST AREA IN THE DEEP VALLEYS AROUND LEWISTON
AND KAMIAH...WHERE UPPER 90S TO NEAR 100 WILL BE POSSIBLE.
THERE IS GOOD AGREEMENT BETWEEN THE GFS...ECMWF...CANADIAN...AND
THE GFS ENSEMBLES THAT A SHORTWAVE TROUGH WILL FLATTEN THE RIDGE
OVER NORTHERN IDAHO FRIDAY NIGHT. THE DRY COLD FRONT THAT WILL
ACCOMPANY THIS SHORTWAVE TROUGH WILL BE MONITORED OVER THE NEXT
COUPLE OF DAYS...MAINLY FOR THE POTENTIAL OF INCREASED FIRE
BEHAVIOR DUE TO WINDS AND LOW RELATIVE HUMIDITY. THE VALLEYS ALONG
THE EAST SLOPES OF THE CASCADES...THE WATERVILLE PLATEAU...AND
PORTIONS OF THE COLUMBIA BASIN LOOK TO HAVE THE BEST CHANCES FOR
SUSTAINED WINDS MEETING RED FLAG CRITERIA.
FOLLOWING THE PASSAGE OF FRIDAY NIGHT`S COLD FRONT...TEMPERATURES
WILL FALL CLOSER TO CLIMATOLOGICAL AVERAGES FOR THE WEEKEND INTO
EARLY NEXT WEEK. THE NEXT CHANCE FOR PRECIPITATION LOOKS TO BE
TUESDAY OR WEDNESDAY AT THE EARLIEST. THE 12Z RUN OF THE GFS HINTS
AT THE POTENTIAL FOR SOME MONSOONAL MOISTURE MOVING INTO NORTHEAST
OREGON AND SOUTHEAST WASHINGTON IN THE TUESDAY TO WEDNESDAY TIME
PERIOD...BUT THE LESS AMPLIFIED ECMWF RETAINS THE DRIER SOUTHWEST
FLOW INTO THE MIDDLE OF NEXT WEEK. GIVEN THE UNCERTAINTY...THE
FORECAST REMAINS DRY. /GKOCH
&&
.AVIATION...
RAIN OVER SOUTHEAST WASHINGTON AND THE CENTRAL AND SOUTHERN
PANHANDLES WILL SLOWLY TRANSLATE TO THE NORTHEAST THIS EVENING.
INTERMITTENT MVFR CEILINGS AND VISIBILITIES WILL CLEAR THE COEUR
D`ALENE...LEWISTON AND SPOKANE VALLEY TERMINALS BY 02Z. MOUNTAIN
OBSCURATIONS OVER THE CENTRAL AND SOUTHERN IDAHO PANHANDLE WILL BE
POSSIBLE THROUGH 06Z...WITH CLOUD BASES AS LOW AS 5-7KFT ABOVE SEA
LEVEL. THERE IS A SLIM CHANCE OF FOG AT LEWISTON AND PULLMAN
OVERNIGHT AFTER THE RAIN PULLS OUT...BUT WARM GROUND TEMPERATURES
AND MIXING JUST ABOVE THE BOUNDARY LAYER WILL PROBABLY PRECLUDE ANY
FOG DEVELOPMENT. /GKOCH
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 60 79 54 88 57 92 / 50 10 0 0 0 0
COEUR D`ALENE 59 79 52 86 53 92 / 50 10 10 0 0 0
PULLMAN 54 80 45 87 48 90 / 60 10 0 0 0 0
LEWISTON 62 87 58 94 61 97 / 50 0 0 0 0 0
COLVILLE 58 81 47 90 48 95 / 30 20 20 0 0 0
SANDPOINT 55 77 48 83 47 87 / 40 20 10 0 0 0
KELLOGG 59 76 54 86 53 91 / 60 20 10 0 0 0
MOSES LAKE 61 85 53 92 57 94 / 0 0 0 0 0 0
WENATCHEE 63 84 60 91 62 93 / 0 0 0 0 0 0
OMAK 58 87 53 92 56 94 / 20 10 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
000
FXUS66 KSEW 222148
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PDT TUE JUL 22 2008
.SYNOPSIS...MARINE CLOUDINESS WILL REMAIN OVER WESTERN WASHINGTON
THROUGH WEDNESDAY MORNING...BUT AN APPROACHING UPPER RIDGE WILL MEAN
MORE AFTERNOON CLEARING. THE RIDGE WILL BRING WARMER SUNNIER WEATHER
THURSDAY AND FRIDAY. A WEAK FRONT WILL PRODUCE CLOUDY SKIES SATURDAY
AND A CHANCE OF RAIN ON THE COAST. SEVERAL WEAK TROUGHS WILL KEEP
TEMPERATURES A LITTLE COOLER WITH LESS SUNSHINE SUNDAY AND MONDAY.
&&
.SHORT TERM...SOUTHWEST FLOW ALOFT CONTINUES OVER WESTERN WASHINGTON
THIS AFTERNOON WITH A WEAK UPPER TROUGH MOVING THROUGH THE AREA.
THERE IS ALSO AN UPPER LOW MOVING NORTHEAST ACROSS EASTERN OREGON...
PRODUCING THUNDERSTORMS OVER EASTERN OREGON AND SOUTHERN IDAHO.
SOUTHERLY ONSHORE FLOW THAT DEVELOPED MONDAY EVENING CONTINUES. THE
BLANKET OF CLOUDS IN THE DEEP MARINE LAYER THAT PUSHED INLAND LAST
NIGHT HAS BEEN GRADUALLY LIFTING THIS AFTERNOON WITH A FEW BREAKS
STARTING TO SHOW UP.
I WILL CALL IT MOSTLY CLOUDY TONIGHT...THOUGH WE COULD SEE A FEW SUN
BREAKS THIS EVENING. EITHER WAY...ONSHORE FLOW WILL CONTINUE TONIGHT
AND THE CLOUD COVER IN THE MARINE LAYER WILL BECOME EXTENSIVE AGAIN
OVERNIGHT.
THE UPPER TROUGH WILL MAKE ITS WAY EAST OF THE CASCADES TONIGHT...
BUT ANOTHER SHORTWAVE WILL MOVE INLAND WEDNESDAY MORNING AND CROSS
THE CASCADES MIDDAY. THE MARINE LAYER OVER WESTERN WASHINGTON WILL
NOT BE AS DEEP IN THE MORNING...ONSHORE FLOW WILL EASE BEHIND THE
UPPER TROUGH...AND THE WIND IN THE PUGET SOUND AREA WILL PROBABLY
SHIFT TO NORTHWEST IN THE AFTERNOON. SO WE SHOULD SEE MORE CLEARING
WEDNESDAY AFTERNOON.
A SMALL UPPER RIDGE WILL REACH THE OFFSHORE WATERS WEDNESDAY NIGHT
AND PROGRESS ACROSS THE FORECAST AREA THURSDAY. WEAK NORTHERLY
ONSHORE FLOW AT THE SURFACE WILL MEAN MUCH LESS MARINE STRATUS
WEDNESDAY NIGHT AND THURSDAY MORNING. SO IT WILL BE A GENERALLY
SUNNY DAY WITH TEMPERATURES CLIMBING BACK INTO THE LOWER 80S IN
PARTS OF THE SOUTHWEST INTERIOR.
THE UPPER RIDGE WILL MOVE EAST OF THE CASCADES THURSDAY NIGHT...AND
AN UPPER TROUGH AND WEAK SURFACE FRONT WILL MOVE INTO THE OFFSHORE
WATERS FRIDAY. LOW LEVEL FLOW WILL ONCE AGAIN TURN SOUTHERLY ONSHORE
AS EARLY AS THURSDAY EVENING...AND A SMALL PRE-FRONTAL SURFACE RIDGE
WILL PROBABLY BOLSTER THIS LATER THURSDAY NIGHT AND DURING THE DAY
FRIDAY. SO FRIDAY IS SOMEWHAT TRICKY...AND I AM LEANING TOWARD A
SOMEWHAT OPTIMISTIC FORECAST FOR THE INTERIOR BUT KEEPING IT MOSTLY
CLOUDY ON THE COAST. MCDONNAL
.LONG TERM...THE UPPER TROUGH AND WEAK FRONT DISCUSSED ABOVE WILL
MOVE ACROSS WESTERN WASHINGTON FRIDAY NIGHT AND SATURDAY. THIS
FEATURE WILL KEEP THE FORECAST AREA MOSTLY CLOUDY...AND I ADDED A
CHANCE OF RAIN TO THE OLYMPICS...COAST...AND COASTAL WATERS.
PRECIPITATION FURTHER INLAND IS NOT OUT OF THE QUESTION...BUT I
THINK IT`S BEST TO LEAVE IT OUT OF THE FORECAST AT THIS TIME.
FOR SUNDAY THROUGH TUESDAY THE LONGER RANGE MODELS CONTINUE TO SHOW
WEAK UPPER SYSTEMS MOVING THROUGH THE REGION...BUT THEY CONTINUE TO
DIFFER FROM RUN-TO-RUN AND BETWEEN MODELS. THE BOTTOM LINE WITH THIS
PATTERN WILL LIKELY BE A LITTLE STRONGER MARINE INFLUENCE THAN IS
TYPICAL FOR LATE JULY -- I.E. AREAS OF NIGHT AND MORNING CLOUDS...
PARTLY TO MOSTLY SUNNY AFTERNOONS AND EVENINGS...AND TEMPERATURES
JUST A LITTLE BELOW NORMAL. MCDONNAL
&&
.AVIATION...WEAK UPPER TROF HAS MOVED TO THE EAST...LEAVING
SOUTHWEST FLOW ALOFT AND ONSHORE SURFACE FLOW. AIR MASS STABLE WITH
AREAS OF MARINE STRATUS EVAPORATING SLOWLY.
STRATUS DOES APPEAR TO BE THINNING IN SATELLITE IMAGERY AND THERE
WILL PROBABLY BE SOME SCATTERING OUT IN THE 00Z-02Z RANGE AROUND
PUGET SOUND. THE COAST WILL LIKELY STAY OVERCAST OR PERHAPS HAVE
ONLY BRIEF CLEARING. ONSHORE GRADIENTS ARE WEAKER THAN YESTERDAY BUT
WILL LIKELY BE STRONG ENOUGH TO BRING STRATUS BACK TO THE PUGET
SOUND TERMINALS OVERNIGHT. EXPECT CEILINGS AROUND 3K FT AFTER 12Z.
KSEA...SW WIND 8-12 KT WILL CONTINUE THROUGH THE NIGHT. BEST GUESS
IS SCATTERED TO BROKEN SKIES FROM 01Z TO 11Z OR SO...THEN OVERCAST
AT ABOUT 3K FT. CHB
&&
.MARINE...LOW LEVEL ONSHORE GRADIENTS DOWN THE STRAIT ARE LESS TODAY
THAN YESTERDAY...WILL KEEP WINDS AT HIGH END SMALL CRAFT ADVISORY
LEVELS FOR NOW. OTHERWISE..EXPECT FLOW WILL REMAIN ONSHORE THROUGH
FRIDAY WITH LIKELY SMALL CRAFT ADVISORY WINDS EACH EVENING IN THE
STRAIT. WILL NEED TO KEEP AN EYE ON THE STRAIT FOR POSSIBLE BRIEF
GALES AT TIMES...INCLUDING TONIGHT.
A WEAK FRONT FRIDAY NIGHT MAY BE STRONG ENOUGH TO TURN WINDS
SOUTHERLY ON THE COAST AND PERHAPS INLAND AS WELL. HAVE GONE HALFWAY
THERE IN THE GRIDS AND THE FORECAST. STILL PLENTY OF TIME FOR THIS
FRONT TO COMPLETELY PETER OUT...AS SEVERAL FRONTS ALREADY HAVE. CHB
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY CENTRAL AND EAST STRAIT.
$$
000
FXUS66 KOTX 222140
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
240 PM PDT TUE JUL 22 2008
.SYNOPSIS...
A SERIES OF DISTURBANCES PASSING THROUGH THE PACIFIC NORTHWEST AND
INTERMOUNTAIN WEST TONIGHT INTO WEDNESDAY EVENING. RIDGING IN SOME
SHAPE OR FORM WILL TAKE HOLD FOR THE REMAINDER OF THE WEEK...THROUGH
THE WEEKEND...AND INTO THE EARLY PART OF NEXT WEEK.
&&
.DISCUSSION...TONIGHT THROUGH THURSDAY NIGHT...BETTER TO JUST LOOK AT
SATELLITE...RADAR...AND OBSERVATIONS THAN MODELS AS FAR AS HOW THE
SHORT TERM SCENARIO UNFOLDS. CLOSED LOW THAT WAS OFF THE
CALIFORNIA COAST YESTERDAY HAS EJECTED INLAND AND IS FIRING OFF
SIGNIFICANT CONVECTION AS IT FOLLOWS A PATH NORTHEAST THROUGH
OREGON AND SOUTHWEST IDAHO. LOTS OF CONVECTIVE DEBRIS CLOUD COVER
IN ADDITION TO THE CLOUDS COUPLED WITH SHOWERS WORKING THEIR WAY
NORTHEAST WILL CLUTTER THE SHORT TERM FORECAST TONIGHT WITH POPS
IN SOME SHAPE OR FORM. SOMEWHAT CLEARER SKIES TO THE NORTHWEST
NEAR THE EAST SLOPES OF THE CASCADES HAVE ALLOWED SURFACE BASED
CONVECTION TO FIRE OFF AND THUS MINOR DEPICTION OF
SHOWERS/THUNDERSTORMS REMAINS THERE THIS EVENING WHILE THE EARLIER
DISCUSSED CLOUD COVER SEEMS TO HAVE INHIBITED THUNDERSTORM
ACTIVITY OVER EXTREME EASTERN WASHINGTON AND NORTHERN IDAHO UP TO
NOW...AND IS EXPECTED TO CONTINUE TO DO SO. A COLD FRONT PASSAGE
WILL SEAL THE DEAL TONIGHT WITH ALL FEATURES TRANSLATING
NORTHEAST/EAST AND AWAY FROM THE FORECAST AREA BY TOMORROW.
ANOTHER SHORTWAVE...A SMALL LOW PRESSURE SYSTEM...IS EXPECTED TO
GLIDE THROUGH SOUTHERN BRITISH COLUMBIA WITHIN CLOSE PROXIMITY TO
THE BORDER AND ALLOW FOR THE POTENTIAL OF SURFACE BASED
AFTERNOON/EARLY EVENING CONVECTION WEDNESDAY. THIS TOO PASSES AND
ALLOWS FOR COMPLICATED RIDGING WITH A SOUTHWEST FLOW THAT FOR NOW
IS DEPICTED WITH LOW BUT NONZERO POPS FOR THURSDAY INTO THURSDAY NIGHT.
WARMING TREND QUITE VIVID IN COMPARISON TO THE COOL DAYTIME HIGHS
THAT HAVE AFFECTED MUCH OF THE DAY TODAY UP TO NOW. /PELATTI
FRIDAY THROUGH TUESDAY...THE LONGWAVE PATTERN OVER NORTH AMERICA
WILL CHANGE LITTLE DURING THE NEXT WEEK. A TROUGH OVER THE GULF OF
ALASKA AND A LARGE HIGH PRESSURE RIDGE OVER THE INTER-MOUNTAIN WEST
WILL PUT THE PACIFIC NORTHWEST IN A DRY SOUTHWEST FLOW THIS
WEEKEND INTO EARLY NEXT WEEK. FRIDAY WILL LIKELY BE THE WARMEST
IN THE NEXT 7 DAYS. 850MB TEMPERATURES OFF THE ECMWF AND GFS ARE
FORECAST TO BE BETWEEN 21-25C OVER EASTERN WASHINGTON AND NORTHERN
IDAHO. THE HOTTEST CONDITIONS SHOULD BE IN THE SOUTHEASTERN
PORTION OF THE FORECAST AREA IN THE DEEP VALLEYS AROUND LEWISTON
AND KAMIAH...WHERE UPPER 90S TO NEAR 100 WILL BE POSSIBLE.
THERE IS GOOD AGREEMENT BETWEEN THE GFS...ECMWF...CANADIAN...AND
THE GFS ENSEMBLES THAT A SHORTWAVE TROUGH WILL FLATTEN THE RIDGE
OVER NORTHERN IDAHO FRIDAY NIGHT. THE DRY COLD FRONT THAT WILL
ACCOMPANY THIS SHORTWAVE TROUGH WILL BE MONITORED OVER THE NEXT
COUPLE OF DAYS...MAINLY FOR THE POTENTIAL OF INCREASED FIRE
BEHAVIOR DUE TO WINDS AND LOW RELATIVE HUMIDITY. THE VALLEYS ALONG
THE EAST SLOPES OF THE CASCADES...THE WATERVILLE PLATEAU...AND
PORTIONS OF THE COLUMBIA BASIN LOOK TO HAVE THE BEST CHANCES FOR
SUSTAINED WINDS MEETING RED FLAG CRITERIA.
FOLLOWING THE PASSAGE OF FRIDAY NIGHT`S COLD FRONT...TEMPERATURES
WILL FALL CLOSER TO CLIMATOLOGICAL AVERAGES FOR THE WEEKEND INTO
EARLY NEXT WEEK. THE NEXT CHANCE FOR PRECIPITATION LOOKS TO BE
TUESDAY OR WEDNESDAY AT THE EARLIEST. THE 12Z RUN OF THE GFS HINTS
AT THE POTENTIAL FOR SOME MONSOONAL MOISTURE MOVING INTO NORTHEAST
OREGON AND SOUTHEAST WASHINGTON IN THE TUESDAY TO WEDNESDAY TIME
PERIOD...BUT THE LESS AMPLIFIED ECMWF RETAINS THE DRIER SOUTHWEST
FLOW INTO THE MIDDLE OF NEXT WEEK. GIVEN THE UNCERTAINTY...THE
FORECAST REMAINS DRY. /GKOCH
&&
.AVIATION...
IN GENERAL...VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH 18Z
WEDNESDAY. REGION WILL BE UNDER INFLUENCE OF MOISTURE PUSH FROM
THE SOUTH AND A LATE DAY DISTURBANCE PASSAGE FROM THE PACIFIC.
MID AND HIGH LEVEL ALTO CUMULUS AND CIRRUS WILL COMPLICATE THE SKY.
BEST MOISTURE CONTENT WILL BE EAST OF A LINE FROM CQV TO KALW
WITH SCATTERED SHOWERS AND THUNDERSTORMS PRODUCING LOCAL MVFR
VISIBILITIES AND MOUNTAIN OBSCURATION DUE TO RAIN AND SMALL
HAIL. CONDITIONS WILL IMPROVE AFTER 06Z WITH DECREASING CLOUDS
OVER THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 60 79 54 88 57 92 / 50 10 0 0 0 0
COEUR D`ALENE 59 79 52 86 53 92 / 50 10 10 0 0 0
PULLMAN 54 80 45 87 48 90 / 60 10 0 0 0 0
LEWISTON 62 87 58 94 61 97 / 50 0 0 0 0 0
COLVILLE 58 81 47 90 48 95 / 30 20 20 0 0 0
SANDPOINT 55 77 48 83 47 87 / 40 20 10 0 0 0
KELLOGG 59 76 54 86 53 91 / 60 20 10 0 0 0
MOSES LAKE 61 85 53 92 57 94 / 0 0 0 0 0 0
WENATCHEE 63 84 60 91 62 93 / 0 0 0 0 0 0
OMAK 58 87 53 92 56 94 / 20 10 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
000
FXUS66 KPQR 222132
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
235 PM PDT TUE JUL 22 2008
.SYNOPSIS...AN UPPER LEVEL LOW OVER SOUTHEAST OREGON WILL LIFT
NORTHEAST OVER MONTANA TONIGHT. ANOTHER UPPER LEVEL TROUGH WILL MOVE
ACROSS NORTHWEST OREGON AND SOUTHWEST WASHINGTON TONIGHT AND WED.
THIS WILL KEEP THE MARINE LAYER FAIRLY DEEP ACROSS THE AREA TONIGHT
AND WED WITH A CHANCE OF LATE NIGHT AND MORNING DRIZZLE ACROSS THE
NORTHWEST PART OF THE DISTRICT. A BRIEF RIDGE WILL POP UP ACROSS THE
NORTHWEST ON THU LEADING TO A WARMER DAY WITH FEWER MORNING CLOUDS.
HOWEVER...PROGRESSIVE WESTERLY FLOW WILL BECOME REESTABLISHED FRI
THROUGH THE WEEKEND FOR MORNING CLOUDS AND AFTERNOON SUNSHINE.
&&
.SHORT TERM...MARINE CLOUDS VERY SLOW TO BURN OFF THIS AFTERNOON.
GIVEN THE SURFACE RIDGE POSITION MANY AREAS WILL HANG ON TO MOSTLY
CLOUDY SKIES THIS EVENING. ANOTHER SHORT WAVE WILL MOVE ACROSS
NORTHWEST OREGON AND SOUTHWEST WASHINGTON TONIGHT. THIS SECOND SHORT
WAVE WILL SERVE TO REINFORCE THE COOL ONSHORE FLOW. DUE TO THE DEPTH
OF THE MARINE LAYER AND A 60 KT JET WILL INTRODUCE A CHANCE OF
MORNING DRIZZLE LATE TONIGHT THROUGH WED MORNING ACROSS THE NORTH
PART OF THE FORECAST AREA. WITH WEAK RIDGING ALOFT IN THE AFTERNOON
WE SHOULD SEE TEMPS WARM A FEW DEGREES OVER TODAYS HIGHS. A BRIEF
UPPER LEVEL RIDGE WILL POP UP OVER THE AREA ON THU. WARMER 850 MB
TEMPS AND DECREASED ONSHORE FLOW WILL ALLOW TEMPERATURES TO WARM
ABOVE NORMAL. HOWEVER...THE WARM UP WILL NOT LAST LONG AS PROGRESSIVE
WESTERLY FLOW BECOMES REESTABLISHED BY FRI.
.LONG TERM...MORNING CLOUDS...AFTERNOON SUN AND NIGHTTIME MARINE
PUSHES WILL BE THE STORY FOR THE EXTENDED. AN UPPER LEVEL DISTURBANCE
WILL SWING THROUGH ON FRIDAY EVENING...REINFORCING THE MARINE LAYER
AND POSSIBLY PROVIDING A LITTLE PATCHY DRIZZLE TO THE NORTHERN
COASTAL ZONES. UPPER HEIGHTS DO NOT RISE MUCH OVER THE WEEKEND SO NO
SIGNIFICANT WARM UP APPEARS TO BE IN THE MAKING THERE. ANOTHER TROUGH
IS SLATED FOR EARLY NEXT WEEK.
&&
.AVIATION...CIGS HAVE RISEN TO VFR...AROUND 3500 FT...THIS AFTERNOON
AND MAY EVEN REACH 4000 FEET YET TODAY. CLOUDS MAY THIN A BIT LATER
THIS AFTERNOON AND EVENING BUT DO NOT EXPECT THEM TO DISSIPATE AS AN
UPPER LEVEL DISTURBANCE MOVES THROUGH FROM THE WEST AND MAINTAINS
RATHER STRONG ONSHORE FLOW AND CONTINUES TO ADVECT THE CLOUD SHIELD
OFFSHORE ONTO LAND. ANOTHER UPPER SHORT WAVE MOVES THROUGH SOUTHWEST
WASHINGTON AND NORTHWEST OREGON LATER TONIGHT AND EARLY WEDNESDAY
AND EXPECT WHAT HOLES DO DEVELOP IN THE CLOUDS LATE TODAY WILL FILL
IN OVERNIGHT...WITH CIGS POSSIBLY LOWERING BACK TO MVFR LATE TONIGHT
AND WEDNESDAY MORNING. MAY SEE AROUND 2500 FEET INLAND AND 1500 FEET
AT THE COAST EARLY WEDNESDAY WITH A LITTLE PATCHY DRIZZLE MAINLY
NEAR THE COAST. TOLLESON
PDX AND APPROACHES...CIGS HAVE RISEN TO VFR...AROUND 3500 FT...THIS
AFTERNOON. CLOUDS MAY THIN A BIT LATER THIS AFTERNOON AND EVENING
WITH CIGS NEAR 4000 FEET BUT DO NOT EXPECT THEM TO DISSIPATE. CIGS
WILL LIKELY LOWER OVERNIGHT AND POSSIBLY REACH 2500 TO 3000 FEET
LATE TONIGHT AND WEDNESDAY MORNING. TOLLESON
&&
.MARINE...ONSHORE FLOW WITH LITTLE ALONG SHORE COMPONENT AND PLENTY
OF CLOUDS WILL CONTINUE TO KEEP WINDS BELOW SMALL CRAFT LEVELS THIS
AFTERNOON AND EVENING. SEAS HAVE INCREASED TO AROUND 7 FT SO FAR
TODAY BUT WILL NOT GO UP MUCH MORE. SEAS WILL EASE BACK DOWN A
COUPLE OF FEET TONIGHT AND WEDNESDAY. SURFACE HIGH PUSHES INLAND A
BIT TO OUR NORTH LATE WEDNESDAY AND WEDNESDAY EVENING MAY PUSH WINDS
ON THE CENTRAL OREGON COAST TO NEAR SMALL CRAFT LEVELS THEN. WINDS
GET CLOSE TO SMALL CRAFT ADVISORY LEVELS AGAIN THURSDAY AFTERNOON
AND EVENING...BUT THEN BACK TO MORE SOUTHWESTERLY FRIDAY WITH THE
NEXT WEAK SYSTEM. TOLLESON
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR/WA...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR THIS
EVENING.
&&
.PRELIMINARY POINT POPS (PROBABILITY OF MEASURABLE PRECIPITATION)
AST 11--00 PDX 110000 SLE 0-0000 EUG 000000
$$
MORE WEATHER INFORMATION ONLINE AT...
Http://weather.gov/portland
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
000
FXUS66 KOTX 222005 AAC
AFDOTX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SPOKANE WA
105 PM PDT TUE JUL 22 2008
.SYNOPSIS...
A MID-LEVEL DISTURBANCE IS SET TO MOVE THROUGH THE AREA ON
TODAY...BRINGING THE CHANCE OF SHOWERS AND THUNDERSTORMS TO THE
EASTERN HALF OF THE AREA. OTHERWISE...RATHER DRY CONDITIONS WITH
SUMMER LIKE TEMPERATURES WILL PERSIST FOR THE NEXT WEEK.
&&
.DISCUSSION...YET ANOTHER CATCH UP UPDATE TO LOWER MAX TEMPS
A BIT MORE GIVEN THE COOLING FROM ONGOING SHOWERS AS WELL AS THE
CLOUD COVER ASSOCIATED WITH IT INHIBITING DAYTIME RADIATION
HEATING. /PELATTI
&&
.AVIATION...
IN GENERAL...VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH 18Z
WEDNESDAY. REGION WILL BE UNDER INFLUENCE OF MOISTURE PUSH FROM
THE SOUTH AND A LATE DAY DISTURBANCE PASSAGE FROM THE PACIFIC.
MID AND HIGH LEVEL ALTO CUMULUS AND CIRRUS WILL COMPLICATE THE SKY.
BEST MOISTURE CONTENT WILL BE EAST OF A LINE FROM CQV TO KALW
WITH SCATTERED SHOWERS AND THUNDERSTORMS PRODUCING LOCAL MVFR
VISIBILITIES AND MOUNTAIN OBSCURATION DUE TO RAIN AND SMALL
HAIL. CONDITIONS WILL IMPROVE AFTER 06Z WITH DECREASING CLOUDS
OVER THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 75 60 79 54 88 57 / 20 30 10 0 0 0
COEUR D`ALENE 75 59 79 52 86 53 / 40 40 10 10 0 0
PULLMAN 75 54 80 45 87 48 / 50 60 10 0 0 0
LEWISTON 76 62 87 58 94 61 / 50 50 0 0 0 0
COLVILLE 85 58 81 47 90 48 / 10 30 20 20 0 0
SANDPOINT 77 55 77 48 83 47 / 40 40 20 10 0 0
KELLOGG 74 59 76 54 86 53 / 40 60 20 10 0 0
MOSES LAKE 88 61 85 53 92 57 / 0 0 0 0 0 0
WENATCHEE 85 63 84 60 91 62 / 0 0 0 0 0 0
OMAK 89 58 87 53 92 56 / 10 20 10 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...RED FLAG WARNING UNTIL 8 PM PDT THIS EVENING FOR NORTHEAST BLUE
MOUNTAINS.
&&
$$
000
FXUS66 KOTX 221908 AAB
AFDOTX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SPOKANE WA
1208 PM PDT TUE JUL 22 2008
.SYNOPSIS...
A MID-LEVEL DISTURBANCE IS SET TO MOVE THROUGH THE AREA ON
TODAY...BRINGING THE CHANCE OF SHOWERS AND THUNDERSTORMS TO THE
EASTERN HALF OF THE AREA. OTHERWISE...RATHER DRY CONDITIONS WITH
SUMMER LIKE TEMPERATURES WILL PERSIST FOR THE NEXT WEEK.
&&
.DISCUSSION...YET ANOTHER UPDATE TO ACCOMMODATE MORE COOLING IN
DAYTIME HIGH TEMPERATURES UNDER THE MID AND HIGH LEVEL CLOUD DECK
AND SHOWERS PASSING OVER EXTREME EASTERN WASHINGTON AND NORTHERN
IDAHO.
&&
.AVIATION...
IN GENERAL...VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH 18Z
WEDNESDAY. REGION WILL BE UNDER INFLUENCE OF MOISTURE PUSH FROM
THE SOUTH AND A LATE DAY DISTURBANCE PASSAGE FROM THE PACIFIC.
MID AND HIGH LEVEL ALTO CUMULUS AND CIRRUS WILL COMPLICATE THE SKY.
BEST MOISTURE CONTENT WILL BE EAST OF A LINE FROM CQV TO KALW
WITH SCATTERED SHOWERS AND THUNDERSTORMS PRODUCING LOCAL MVFR
VISIBILITIES AND MOUNTAIN OBSCURATION DUE TO RAIN AND SMALL
HAIL. CONDITIONS WILL IMPROVE AFTER 06Z WITH DECREASING CLOUDS
OVER THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 77 60 79 54 88 57 / 20 30 10 0 0 0
COEUR D`ALENE 78 59 79 52 86 53 / 40 40 10 10 0 0
PULLMAN 75 54 80 45 87 48 / 50 60 10 0 0 0
LEWISTON 76 62 87 58 94 61 / 50 50 0 0 0 0
COLVILLE 85 58 81 47 90 48 / 10 30 20 20 0 0
SANDPOINT 80 55 77 48 83 47 / 40 40 20 20 0 0
KELLOGG 74 59 76 54 86 53 / 40 60 20 10 0 0
MOSES LAKE 88 61 85 53 92 57 / 0 0 0 0 0 0
WENATCHEE 85 63 84 60 91 62 / 0 0 0 0 0 0
OMAK 89 58 87 53 92 56 / 10 20 10 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...RED FLAG WARNING UNTIL 8 PM PDT THIS EVENING FOR NORTHEAST BLUE
MOUNTAINS.
&&
$$
000
FXUS66 KOTX 221840
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1140 AM PDT TUE JUL 22 2008
.SYNOPSIS...
A MID-LEVEL DISTURBANCE IS SET TO MOVE THROUGH THE AREA ON
TODAY...BRINGING THE CHANCE OF SHOWERS AND THUNDERSTORMS TO THE
EASTERN HALF OF THE AREA. OTHERWISE...RATHER DRY CONDITIONS WITH
SUMMER LIKE TEMPERATURES WILL PERSIST FOR THE NEXT WEEK.
&&
.DISCUSSION...FAIRLY DENSE MID AND HIGH CLOUD WORKING ITS WAY
AHEAD OF AN AREA OF CONVECTION PASSING THROUGH THROUGH EASTERN
OREGON AND SOUTHWEST IDAHO THIS MORNING IS INHIBITING DAYTIME
HEATING...MORE HEAVILY NEAR LEWISTON AND PULLMAN THAN ALONG ITS
PERIPHERY TO THE NORTH AND WEST. HAVE ADJUSTED TEMPERATURES A
BIT TO ACCOMMODATE. /PELATTI
&&
.AVIATION...
IN GENERAL...VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH 18Z
WEDNESDAY. REGION WILL BE UNDER INFLUENCE OF MOISTURE PUSH FROM
THE SOUTH AND A LATE DAY DISTURBANCE PASSAGE FROM THE PACIFIC.
ID AND HIGH LEVEL ALTOCUMULUS AND CIRRUS WILL COMPLICATE THE SKY.
BEST MOISTURE CONTENT WILL BE EAST OF A LINE FROM KCQV TO KALW
WITH SCATTERED SHOWERS AND THUNDERSTORMS PRODUCING LOCAL MVFR
VISIBILITIES AND MOUNTAIN OBSCURATION DUE TO RAIN AND SMALL
HAIL. CONDITIONS WILL IMPROVE AFTER 06Z WITH DECREASING CLOUDS
OVER THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 80 60 79 54 88 57 / 20 30 10 0 0 0
COEUR D`ALENE 79 59 79 52 86 53 / 40 40 10 10 0 0
PULLMAN 75 54 80 45 87 48 / 50 60 10 0 0 0
LEWISTON 76 62 87 58 94 61 / 50 50 0 0 0 0
COLVILLE 85 58 81 47 90 48 / 10 30 20 10 0 0
SANDPOINT 80 55 77 48 83 47 / 40 40 20 10 0 0
KELLOGG 74 59 76 54 86 53 / 40 60 20 10 0 0
MOSES LAKE 88 61 85 53 92 57 / 0 0 0 0 0 0
WENATCHEE 85 63 84 60 91 62 / 0 0 0 0 0 0
OMAK 89 58 87 53 92 56 / 10 20 10 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...RED FLAG WARNING UNTIL 8 PM PDT THIS EVENING FOR NORTHEAST BLUE
MOUNTAINS.
&&
$$
000
FXUS66 KOTX 221631 AAA
AFDOTX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE SPOKANE WA
931 AM PDT TUE JUL 22 2008
.SYNOPSIS...
A MID-LEVEL DISTURBANCE IS SET TO MOVE THROUGH THE AREA ON
TODAY...BRINGING THE CHANCE OF SHOWERS AND THUNDERSTORMS TO THE
EASTERN HALF OF THE AREA. OTHERWISE...RATHER DRY CONDITIONS WITH
SUMMER LIKE TEMPERATURES WILL PERSIST FOR THE NEXT WEEK.
&&
.DISCUSSION...MINOR ADJUSTMENTS MADE TO TODAYS POPS AND
TEMPERATURE...SO MINOR IN FACT THAT THEY MIGHT NOT AFFECT THE TEXT
PRODUCTS AT ALL. 12Z KOTX SOUNDING IS QUITE MOIST COMPARED TO PAST
SOUNDINGS OF LATE WITH A PRECIPITABLE WATER APPROACHING 0.72 INCHES
WHICH IS A BIT OVER 120 PERCENT OF NORMAL FOR THE MONTH. SOUNDING
SHOWS CONSIDERABLE SOUTHWEST WINDS ALOFT WITH A STORM MOTION TO
THE NORTHEAST AT ABOUT 20 MPH OR SO. POPS ACCOUNT FOR ANY
CONVECTION CURRENTLY IN EASTERN OREGON AND SOUTHWEST IDAHO THAT
MIGHT CONTINUE TO BE ACTIVE AND MOVES OVER EXTREME EASTERN
WASHINGTON AND NORTHERN IDAHO AS WELL CONVECTIVE SHOWERS AND
THUNDERSTORMS THAT MIGHT FORM AHEAD OF A COLD FRONT EXTENDING FROM
A LOW PRESSURE SYSTEM PASSING THROUGH BRITISH COLUMBIA LATER TODAY
AND TONIGHT. /PELATTI
&&
.AVIATION...
IN GENERAL...VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH 18Z
WEDNESDAY. REGION WILL BE UNDER INFLUENCE OF MOISTURE PUSH FROM
THE SOUTH AND A LATE DAY DISTURBANCE PASSAGE FROM THE PACIFIC.
ID AND HIGH LEVEL ALTOCUMULUS AND CIRRUS WILL COMPLICATE THE SKY.
BEST MOISTURE CONTENT WILL BE EAST OF A LINE FROM KCQV TO KALW
WITH SCATTERED SHOWERS AND THUNDERSTORMS PRODUCING LOCAL MVFR
VISIBILITIES AND MOUNTAIN OBSCURATION DUE TO RAIN AND SMALL
HAIL. CONDITIONS WILL IMPROVE AFTER 06Z WITH DECREASING CLOUDS
OVER THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 80 60 79 54 88 57 / 20 30 10 0 0 0
COEUR D`ALENE 79 59 79 52 86 53 / 40 40 10 10 0 0
PULLMAN 76 54 80 45 87 48 / 50 60 10 0 0 0
LEWISTON 82 62 87 58 94 61 / 50 50 0 0 0 0
COLVILLE 85 58 81 47 90 48 / 10 30 20 10 0 0
SANDPOINT 80 55 77 48 83 47 / 40 40 20 10 0 0
KELLOGG 74 59 76 54 86 53 / 40 60 20 10 0 0
MOSES LAKE 88 61 85 53 92 57 / 0 0 0 0 0 0
WENATCHEE 86 63 84 60 91 62 / 0 0 0 0 0 0
OMAK 89 58 87 53 92 56 / 10 20 10 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...RED FLAG WARNING UNTIL 8 PM PDT THIS EVENING FOR NORTHEAST BLUE
MOUNTAINS.
&&
$$
000
FXUS66 KSEW 221550
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
930 AM PDT TUE JUL 22 2008
.SYNOPSIS...STRONGER ONSHORE FLOW PUSHED A DEEP MARINE LAYER INTO
WESTERN WASHINGTON OVERNIGHT. THE BLANKET OF CLOUDS WILL ONLY GIVE
WAY TO PARTLY SUNNY SKIES THIS AFTERNOON. WEDNESDAY WILL ALSO START
CLOUDY BUT WITH MORE AFTERNOON CLEARING. A RIDGE WILL BRING SUNNY
AND WARMER WEATHER THURSDAY AND FRIDAY. ANOTHER TROUGH WILL KEEP THE
WEATHER COOLER WITH LESS SUNSHINE THIS WEEKEND.
&&
.SHORT TERM...SOUTHWEST FLOW ALOFT CONTINUES OVER WESTERN WASHINGTON
JUST AHEAD OF AN UPPER TROUGH THAT EXTENDS FROM NORTHWEST CANADA
INTO OUR COASTAL WATERS. THE UPPER LOW THAT IS PRODUCING
THUNDERSTORMS OVER EASTERN OREGON IS DRIFTING NORTHEAST OVER
NORTHERN CALIFORNIA. AS EXPECTED SOUTHERLY ONSHORE GRADIENTS
DEVELOPED MONDAY EVENING...PUSHING A DEEP MARINE LAYER INLAND
OVERNIGHT AND LEAVING THE AREA UNDER A BLANKET OF LOW CLOUDS THIS
MORNING.
THE UPPER TROUGH WILL MOVE SLOWLY INLAND TODAY AND MAKE ITS WAY EAST
OF THE CASCADES TONIGHT. GIVEN THE DEPTH OF THE MARINE LAYER --
AROUND 5000 FT -- AND THE STRENGTH OF ONSHORE FLOW...THE LOW CLOUD
LAYER WILL LIFT AND BREAK SLOWLY TODAY. THE FORECAST FOR SKIES
BECOMING ONLY PARTLY SUNNY DURING THE AFTERNOON LOOKS RIGHT.
ONSHORE FLOW WILL BE SIMILARLY STRONG THROUGH TONIGHT...SO MARINE
STRATUS SHOULD FILL BACK IN OVERNIGHT. ANOTHER UPPER TROUGH WILL
REACH THE AREA WEDNESDAY MORNING AND MOVE INTO EASTERN WASHINGTON BY
AFTERNOON...WHILE A MINOR UPPER RIDGE BEGINS APPROACHING THE
FORECAST AREA FROM THE WEST. THE MARINE LAYER OVER WESTERN
WASHINGTON WILL NOT BE AS DEEP IN THE MORNING...ONSHORE FLOW WILL
EASE BEHIND THE UPPER TROUGH...AND THE WIND IN THE PUGET SOUND AREA
WILL PROBABLY SHIFT TO NORTHWEST IN THE AFTERNOON. SO WE SHOULD SEE
MORE CLEARING WEDNESDAY AFTERNOON.
THE UPPER RIDGE WILL PROGRESS ACROSS THE FORECAST AREA THURSDAY.
WEAK NORTHERLY ONSHORE FLOW AT THE SURFACE WILL MEAN MUCH LESS
MARINE STRATUS IN THE MORNING. SO IT WILL BE A GENERALLY SUNNY DAY
WITH TEMPERATURES CLIMBING BACK INTO THE LOWER 80S IN PARTS OF THE
SOUTHWEST INTERIOR. MCDONNAL
.LONG TERM...HERE IS THE LONG TERM SECTION FROM THE EARLY MORNING
ISSUANCE OF THE FORECAST DISCUSSION -- THE GFS/ECMWF HAVE TRENDED A
LITTLE FASTER WITH THE NEXT TROUGH...NOW SHOWN TO FLATTEN THE RIDGE
DOWN BY FRIDAY A | 
