[
W WA |
SW WA and W OR |
SE WA and NE OR |
NE WA and N ID
]
Western Washington
916
FXUS66 KSEW 231659
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 AM PST MON NOV 23 2009
.SYNOPSIS...A WARM FRONT WILL BRING SOME RAIN TO WESTERN WASHINGTON
TODAY...MAINLY ALONG THE COAST AND IN THE NORTH. A WEAK COLD FRONT
WILL MOVE INLAND TONIGHT. WEAK HIGH PRESSURE WILL MOVE ACROSS THE
AREA TUESDAY. A WEAK WARM FRONT WILL MOVE THROUGH THE AREA TUESDAY
NIGHT...FOLLOWED BY ANOTHER WEAK COLD FRONT WEDNESDAY NIGHT AND
THANKSGIVING DAY....FOLLOWED BY AN UPPER TROUGH ON FRIDAY.
&&
.SHORT TERM...A WEAK WARM FRONT CLIPPING THE AREA THIS MORNING IS
BRINGING SPOTTY LIGHT RAIN TO MUCH OF THE AREA. THE PRECIP CAME IN
QUICKER AND FURTHER INLAND THAN WAS EXPECTED YESTERDAY. EVEN THE NEW
12Z NAM IS DRY THIS MORNING WITH THE EXCEPTION OF THE COAST. THE
GFS/ECMWF APPEAR TO HAVE A BETTER HANDLE ON THIS SHOWING SOME LIGHT
QPF THIS MORNING...INTENSIFYING DURING THE AFTERNOON AS THE MAIN
FRONT APPROACHES. QPF AMOUNTS APPEAR HIGHEST ON THE COAST/OLYMPIC
PENINSULA WHERE UP TO 1 INCH OF RAIN COULD FALL. MUCH LESS AMOUNTS
EXPECTED ELSEWHERE WITH SNOW LEVELS EXPECTED TO RISE THROUGH THE
DAY..RISING TO OVER 5000 FEET BY THIS EVENING. SNOW ACCUMULATIONS IN
THE PASSES SHOULD REMAIN BELOW ADVISORY CRITERIA...MAYBE UP TO A FEW
INCHES THIS EVENING BEFORE CHANGING TO RAIN.
THE FRONT DISSIPATES OVER WRN WA UNDER A BUILDING UPPER RIDGE
TONIGHT. THERE COULD BE SOME RESIDUAL LIGHT RAIN/DRIZZLE AND LOW
CLOUDS HANGING IN THROUGH TUESDAY MORNING. COULD END UP BEING A
RATHER MURKY DAY TUESDAY WITH SUBSIDENCE ALOFT AND RESIDUAL MOISTURE
TRAPPED IN THE LOWER LEVELS. QPF WILL BE LIGHT WITH HIGHER SNOW
LEVELS...THUS SNOW IN THE PASSES IS NOT EXPECTED.
HIGH PRESSURE BUILDS STRONGER OVER THE AREA TUESDAY NIGHT AND EARLY
WEDNESDAY...THEN SHIFTS EWD WEDNESDAY AFTERNOON AS THE NEXT FRONTAL
BAND APPROACHES. IT LOOKS LIKE PRECIP SHOULD HOLD OFF DURING THE DAY
THE HEIGHTS AND RISING THICKNESS VALUES INDICATING WARMER AIR ALOFT.
PRECIP ASSOCIATED THE THE FRONTAL BAND COULD START TO AFFECT THE
OLYMPIC PENINSULA AND COAST BY LATE IN THE DAY. MERCER
.LONG TERM...PREVIOUS DISCUSSION FOLLOWS...THE MODELS DISAGREE ON
HOW THE PATTERN WILL CHANGE IN THE LONGER RANGE. THE GFS SHOWS A
MUCH DRIER SOLUTION WHILE THE EUROPEAN MODEL IS WETTER. SO
CONFIDENCE IN THE EXTENDED FORECAST THANKSGIVING DAY THROUGH SUNDAY
IS RATHER LOW AND THE APPROACH IS A BROAD BRUSH. IN A VERY GENERAL
SENSE THEY AGREE THAT THANKSGIVING DAY THROUGH FRIDAY NIGHT WILL BE
WETTER AS THE FRONTAL SYSTEM SITTING OFFSHORE WEDNESDAY MOVES
THROUGH THE AREA. AND THEY AGREE THAT AN UPPER RIDGE WILL BUILD OVER
THE AREA OVER THE WEEKEND ...REDUCING THE THREAT OF WET WEATHER TO A
CHANCE. MCDONNAL
&&
.HYDROLOGY...THE SKOKOMISH RIVER REMAINS JUST ABOVE FLOOD STAGE
EARLY THIS MORNING. THE CURRENT RIVER MODEL FORECAST SHOWS IT
DROPPING BELOW FLOOD STAGE LATER TODAY...BUT THE ACTUAL RESULT WILL
DEPEND HEAVILY UPON THE OPERATION OF CUSHMAN DAM #2 ON THE NORTH
FORK OF THE RIVER. A PLANNED RELEASE OF WATER FROM THE DAM BEGAN
EARLY SATURDAY AND CONTINUES EARLY THIS MORNING.
TWO FRONTAL SYSTEMS WILL MOVE THROUGH THE AREA THROUGH WEDNESDAY
NIGHT...AND THE SNOW LEVEL WILL GRADUALLY CLIMB TO 7000-8000 FT.
THESE SYSTEMS WILL NOT BRING ENOUGH PRECIPITATION FOR FLOODING
CONCERNS ON ANY WESTERN WASHINGTON RIVERS...WITH THE POSSIBLE
EXCEPTION OF THE SKOKOMISH RIVER.
MODELS DIFFER ON THE THURSDAY SYSTEM. THE NAM IS LESS PROGRESSIVE
AND HANGS THE FRONTAL BOUNDARY UP OVER THE OLYMPIC PENINSULA.
RAINFALL RATES DO NOT LOOK INCREDIBLE BUT COULD BE ENOUGH FOR MINOR
FLOODING CONCERNS ON THE SKOKOMISH RIVER. THE OTHER MODELS ARE
WEAKER AND MUCH MORE PROGRESSIVE WITH THE FRONT AND WOULD NOT IMPLY
ANY FLOOD THREAT.
NO FLOODING IS EXPECTED ON THE GREEN RIVER AT ANY TIME DURING THE
FORECAST PERIOD.
&&
.AVIATION...AN UPPER LEVEL TROUGH CROSSING SOUTHERN BRITISH COLUMBIA
WILL PUSH A WEAKENING COLD FRONT TO THE WA COAST AROUND 00Z. AIR
MASS IS STABLE WITH GRADUALLY LOWERING CIGS IN RAIN EXPECTED AHEAD
OF THE WEAK FRONT. THE FRONT WILL MOVE INLAND AFTER 00Z THEN
EVENTUALLY DISSIPATE OVER SW WA 06Z-12Z.
LATEST OBS SHOW CIGS GENERALLY BKN-0VC040-060 OVER THE INTERIOR WITH
SOME SPOTTY MVFR STILL IN THE PROCESS OF DISSIPATING...WITH
LOCALIZED LIGHT RAIN INTERFERING WITH THIS. WILL SHOW A MINOR BREAK
IN THE RAIN AND KEEP CIGS UP THROUGH ABOUT 22Z BASED ON AN APPARENT
BREAK IN THE HIGHER CLOUDS ON IR IMAGERY. SHOULD SEE CIGS LOWER WITH
MORE WIDESPREAD RAIN TOWARD 00Z AS THE MAIN FRONT APPROACHES.
KSEA...WILL KEEP CIGS BKN-OVC040-060 FOR MOST OF THE DAY THEN
LOWERING TO BKN-OVC020-030 AFTER 03Z. NOT COMPLETELY CONFIDENT THAT
THE CIGS WILL GET DOWN TO BKN020 WITH THE FRONT SO WEAK...BUT THE
WINDS WILL WEAKEN TONIGHT AS WELL WHICH WOULD ALLOW CIGS TO LOWER A
BIT MORE. EXPECT SURFACE WINDS TO REMAIN S THROUGH THIS EVENING. KAM
&&
.MARINE...THE WEAKENING COLD FRONT WAS UP AROUND 49N/128.5W AROUND
16Z THIS MORNING. MODELS BRING IT TO THE N COAST LATE THIS
AFTERNOON...12Z NAM A LITTLE FASTER THAN THE 12Z GFS. MODEL
SOLUTIONS WEAKENING THIS FRONT AS IT MOVES INLAND SEEM ON TRACK
SINCE WATER VAPOR IMAGERY SHOWS WHAT APPEARS TO BE THE LAST
SHORTWAVE MOVING UP THE FRONT ALMOST TO QUEEN CHARLOTTE SOUND. MAIN
QUESTION AT THIS POINT IS HOW STRONG THE WINDS WILL BE. SHOULD SEE A
LITTLE STRENGTHENING IN THE WINDS THROUGH EARLY AFTERNOON...THEN
WEAKENING. WILL LEAVE THE GALES COAST/WEST ENTRANCE UP AND SCA
ELSEWHERE EXCEPT CENTRAL STRAIT. FORECAST ADVERTISES SCA W WINDS IN
THE STRAIT BEHIND THE FRONT TONIGHT...BUT NEITHER THE GFS OR NAM
SUPPORT THAT. WILL HOLD OFF ON THE ADVISORIES AND SEE WHAT THE 12Z
WRF-GFS SHOWS. WINDS SHOULD BE BELOW ADVISORY LEVELS
TUESDAY...EXCEPT FOR THE COAST. KAM
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...A FLOOD WARNING REMAINS IN EFFECT FOR THE SKOKOMISH RIVER
IN MASON COUNTY.
PZ...GALE WARNING COAST AND WEST ENTRANCE.
SMALL CRAFT ADVISORY ALL OTHER WATERS EXCEPT THE CENTRAL
STRAIT.
SMALL CRAFT ADVISORY FOR ROUGH BAR CONDITIONS AT GRAYS HARBOR
ENTRANCE.
$$
WWW.WEATHER.GOV/SEATTLE
FOR AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION...PLEASE SEE
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML.
[
W WA |
SW WA and W OR |
SE WA and NE OR |
NE WA and N ID
]
Southwestern Washington and Western Oregon
312
FXUS66 KPQR 231638
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
838 AM PST MON NOV 23 2009
.SYNOPSIS...A WEAK WARM FRONT OFF THE COAST WILL SHIFT NORTHEAST
TODAY...THEN A WEAK COLD FRONT WILL SAG SE INTO NW OREGON TONIGHT.
THE FRONT WILL STALL LATE TONIGHT...THEN LIFT NE AS A WARM FRONT ON
TUE. THE NEXT FRONTAL SYSTEM IS NOT EXPECTED TO MOVE IN UNTIL LATE
THURSDAY.
&&
.SHORT TERM...THE MAIN THREAT FOR RAIN THOUGH TODAY SHOULD BE OVER
THE NW PART OF THE FORECAST AREA...WHERE ISENTROPIC LIFT IS BEST
AHEAD OF THE WARM FRONT OFFSHORE.
MODELS INDICATE A COLD FRONT SAGGING DOWN INTO THE REGION LATE TODAY
AND TONIGHT. WILL NEED TO INCLUDE POPS MOST AREAS BY TONIGHT AND
EARLY TUE WITH BAROCLINIC ZONE OVER THE AREA...BUT WITH WEAK DYNAMICS
POPS WILL BE LIMITED TO CHANCE TO LIKELY CATEGORY. FRONT LIFTS BACK
TO THE N LATE TUE AND TUE NIGHT WITH THE UPPER RIDGE
REBOUNDING...RESULTING IN DIMINISHING POPS BY TUE NIGHT...AND A DRY
DAY WED. WOLFE
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
MODELS IN SOME AGREEMENT ON BRINGING A FRONTAL SYSTEM AND ITS
ASSOCIATED UPPER LEVEL TROF THROUGH THE REGION THU/THU NIGHT FOR A
RETURN TO WET WEATHER. AFTER THIS SYSTEM MOVES THROUGH...THE WEAK
HIGH PRES RIDGE REASSERTS ITSELF OVER THE FORECAST AREA...KEEPING
MOST ENERGY NORTH OF FORECAST AREA. FOG MAY BE MORE OF A PROBLEM IN
THE EXTENDED.
&&
.AVIATION...MUCH MORE TRANQUIL TODAY. PRIMARILY VFR CONDITIONS
ACROSS THE REGION. A WARM FRONT APPROACHING FROM THE WEST WILL
SPREAD AREAS OF MVFR WITH OCCASIONAL RA ALONG THE COAST AROUND 20Z.
MAY SEE SOME SPRINKLES INLAND AS THE WARM FRONT PASSES THROUGH...BUT
REMAINING GENERALLY DRY WITH VFR THROUGH 02Z.
KPDX AND APPROACHES...NO ADVERSE WEATHER IMPACTS EXPECTED. VFR
CONDITIONS TO REMAIN THROUGH 06Z TONIGHT.
&&
.MARINE...LOW PRESSURE IS MOVING INTO VANCOUVER ISLAND THIS
MORNING...PUSHING A WARM FRONT INTO THE WA/OR COASTAL WATERS.
ASSOCIATED COLD FRONT EXTENDS SW FROM LOW AND WILL NOT DIRECTLY MOVE
THROUGH WATERS UNTIL MIDWEEK. WINDS JUST BEHIND WARM FRONT MAY
APPROACH GALE IN A FEW GUSTS...BUT FOR NOW SCA FOR WINDS/SEAS APPEAR
SUFFICIENT. SEAS WILL REMAIN IN THE 10-13 FT RANGE THROUGH TODAY...
BUT MAY FALL BELOW 10 FEET FOR A TIME TONIGHT AND TUE. GENERALLY
TRANQUIL WEATHER THEN EXPECTED INTO WED...THEN THE COLD FRONT WILL
FINALLY SLIDE ACROSS THE COASTAL WATERS WED NIGHT/THU. SOME MODELS
SHOW THE POSSIBILITY OF A STRONG LOW DEVELOPING ALONG THIS FRONT OFF
THE OREGON COAST WED NIGHT OR EARLY THU...WILL NEED TO MONITOR THIS
FOR POTENTIAL GALES DURING THAT TIME PERIOD. WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
WA/OR...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS CAPE SHOALWATER TO
FLORENCE OUT 0-60 NM THROUGH TUE.
SMALL CRAFT ADVISORY FOR WINDS CAPE SHOALWATER TO CASCADE
HEAD OUT 0-60 NM AND CASCADE HEAD TO FLORENCE OUT 20-60
NM TODAY.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR THROUGH
THIS EVENING.
&&
$$
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.
[
W WA |
SW WA and W OR |
SE WA and NE OR |
NE WA and N ID
]
Southeastern Washington and Northeastern Oregon
794
FXUS66 KPDT 231731 AAB
AFDPDT
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
930 AM PST MON NOV 23 2009
UPDATED AVIATION DISCUSSION
.SHORT TERM...HIGH PRESSURE THAT IS PROVIDING A MOSTLY SUNNY
BEGINNING WILL GIVE WAY TO A DISTURBANCE MOVG INTO THE PACNW THIS
AFTERNOON. THIS SHOULD SPREAD CLOUDS INTO PORTIONS OF THE AREA
ESPECIALLY OVER THE WA CASCADES WHERE A FEW SHOWERS MAY DEVELOP LATE
THIS AFTERNOON AND THEN SPREAD EAST LATER ON. OTHERWISE HIGH TEMPS
SEEM TO BE IN THE BALLPARK AND THE SHORT TERM FORECAST APPEARS ON
TRACK FOR NOW.
&&
.AVIATION DISCUSSION...18Z TAFS...VFR CONDITIONS WILL PREVAIL
THROUGH THE DAY TODAY WITH INCREASING MID AND HIGH CLOUDS THIS
AFTERNOON. ANOTHER WEATHER DISTURBANCE WILL MOVE INTO THE AREA
OVERNIGHT TONIGHT WITH ANOTHER CHANCE OF RAIN AND MOUNTAIN SNOW.
KRDM IN CENTRAL OREGON WILL LIKELY NOT SEE ANY PRECIPITATION FROM
THIS SYSTEM. THERE MAY BE BRIEF PERIODS OF MVFR TONIGHT IN RAIN/SNOW
SHOWERS...ESPECIALLY AT KDLS...KYKM AND KPSC...AND TO A LESSER
DEGREE AT KPDT AND KALW. WINDS MAINLY LESS THAN 15 KTS...BUT PERHAPS
15 TO 20 KTS AT TIMES NEAR SHOWERS. 76
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 47 34 48 33 / 0 20 20 0
ALW 47 36 47 35 / 0 20 20 0
PSC 48 34 47 32 / 10 20 10 0
YKM 44 28 46 30 / 10 30 20 0
HRI 49 32 48 31 / 0 20 10 0
ELN 43 30 45 31 / 10 30 20 10
RDM 46 26 50 25 / 0 10 10 0
LGD 40 29 44 27 / 0 20 20 0
GCD 43 27 47 27 / 0 10 10 0
DLS 46 35 48 37 / 10 30 20 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
TODAY : GREEN
TUESDAY : GREEN
WEDNESDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
97
[
W WA |
SW WA and W OR |
SE WA and NE OR |
NE WA and N ID
]
Northeastern Washington and Northern Idaho
471
FXUS66 KOTX 231834
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
1034 AM PST MON NOV 23 2009
.SYNOPSIS...
WEAK HIGH PRESSURE OVER THE REGION WILL PROMOTE DRY BUT MOSTLY
CLOUDY CONDITIONS TODAY. A WEAK PACIFIC WARM FRONT WILL BRING A
POSSIBILITY OF VERY LIGHT PRECIPITATION TONIGHT...WITH GENERALLY
DRY BUT CLOUDY WEATHER RETURNING TUESDAY AND THROUGH THANKSGIVING.
ON FRIDAY A COLD FRONT WILL PASS THROUGH WITH ANOTHER REASONABLE
CHANCE OF MOUNTAIN SNOW AND VALLEY RAIN OR SNOW. CONDITIONS WILL
REMAIN CLOUDY AND UNSETTLED INTO NEXT WEEKEND.
&&
.DISCUSSION...
A SHORTWAVE RIDGE WILL BUILD OVER THE REGION TODAY FOR MAINLY DRY
CONDITIONS ACROSS THE INLAND NORTHWEST. SATELLITE WATER VAPOR
IMAGERY SHOWS THE MOISTURE ASSOCIATED WITH A WEAK WARM FRONT
APPROACHING VANCOUVER ISLAND THIS MORNING. SOME LIGHT RETURNS ARE
SHOWING UP ON REGIONAL RADAR MOSAIC BUT SURFACE OBSERVATIONS
INDICATE THAT THIS IS JUST THE MID LEVEL CLOUD DECK MOVING IN FROM
THE WEST. CLOUDS WILL BE ON THE INCREASE THIS AFTERNOON BUT ONLY
VERY LIGHT PRECIPITATION EXPECTED ACROSS THE CASCADE CREST AND
NORTHERN TIER AS MOIST ISENTROPIC UPGLIDE SPREADS ACROSS THE
CASCADES TO THE NORTHERN MTS THIS EVENING. ONLY MINOR UPDATES MADE
TO THE FORECAST THIS MORNING. POPS WERE REDUCED A BIT AND TEMPS
AND SKY COVER ADJUSTED TO ACCOUNT FOR TRENDS IN OBSERVATIONS.
/KELCH
&&
.AVIATION...
A SHORTWAVE RIDGE WILL MOVE OVERHEAD TODAY RESULTING IN LARGELY
VFR CONDITIONS AREA WIDE. A WEAK WARM FRONT WILL MOVE INTO
NORTHERN WA AND THE ID PANHANDLE TONIGHT RESULTING IN RAIN AND
SNOW SHOWERS. HOWEVER...SOME UNCERTAINTY EXISTS ON WHETHER OR NOT
PRECIP...AND SUBSEQUENT MVFR CIGS...WILL REACH THE KGEG-KCOE
CORRIDOR LATE TONIGHT. LIGHT UPSLOPE WINDS MAY ALLOW LOW STRATUS
TO DEVELOP IN THE KGEG-KCOE AREA AFTER 10Z TUESDAY. /EK
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 38 33 39 31 41 31 / 0 50 10 10 0 0
COEUR D'ALENE 39 33 39 31 41 31 / 0 50 10 10 0 0
PULLMAN 39 34 41 29 43 32 / 10 50 30 0 0 0
LEWISTON 45 34 45 34 45 34 / 10 30 20 0 0 0
COLVILLE 40 34 40 29 40 27 / 20 70 10 20 20 10
SANDPOINT 37 30 35 27 36 26 / 10 60 10 20 20 10
KELLOGG 35 28 37 28 40 29 / 20 60 30 10 10 0
MOSES LAKE 43 28 44 31 44 30 / 0 10 10 0 0 0
WENATCHEE 42 31 43 32 43 32 / 10 20 10 10 10 0
OMAK 40 27 43 29 43 29 / 40 60 10 20 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
WA...NONE.
&&
$$
[
W WA |
SW WA and W OR |
SE WA and NE OR |
NE WA and N ID
]
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