[
W WA |
SW WA and W OR |
SE WA and NE OR |
NE WA and N ID
]
Western Washington
159
FXUS66 KSEW 092300
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PST TUE FEB 9 2010
.SYNOPSIS...AN APPROACHING FRONT WILL BRING INCREASING CLOUDS
TONIGHT AND RAIN BY LATE WEDNESDAY AFTERNOON. A STRONGER AND WETTER
FRONTAL SYSTEM WILL AFFECT THE AREA LATE WEDNESDAY NIGHT AND
THURSDAY. STRONGER SOUTHWEST FLOW ALOFT OVER THE REGION WILL SEND
MORE WEATHER SYSTEMS ACROSS THE AREA FRIDAY THROUGH THE WEEKEND.
&&
.SHORT TERM...WESTERN WASHINGTON CLEARED OUT THIS AFTERNOON EXCEPT
FOR A PATCH AROUND SOUTH PUGET SOUND. THIS WILL CONTINUE TO ERODE
BUT THE SUN MAY SET BEFORE IT IS COMPLETELY GONE. OTHERWISE SHOULD
BE A CLEAR EVENING. APPROACHING FRONT WILL SPREAD HIGH THEN MID
CLOUDS OVER THE AREA TONIGHT. THIS WILL LIMIT FOG BUT PATCHY FOG IS
STILL LIKELY IN SUSCEPTIBLE LOCATIONS. OVERNIGHT LOWS SHOULD BE A
BIT HIGHER THAN LAST NIGHT...BUT STILL IN THE 30S AND LOWER 40S.
MODELS HAVE CONVERGED ON A WEDNESDAY SOLUTION THAT HAS RAIN
DEVELOPING ON THE COAST IN THE MORNING AND SPREADING INLAND DURING
THE AFTERNOON. HAVE MOSTLY FOLLOWED THE CATEGORICAL MOS POPS BUT
HAVE SLIGHTLY LOWER POPS FOR THE SEATTLE AREA...JUST LIKELIES.
WESTERLY FLOW ALOFT COULD PUT SEATTLE IN A RAIN SHADOW FOR AWHILE.
AFTER THIS FIRST SYSTEM PASSES WEDNESDAY EVENING...A WARM FRONT
MOVES UP FROM THE SOUTH LATE WEDNESDAY NIGHT. THIS WILL SPREAD RAIN
OVER THE AREA AGAIN AND ALSO BRING BREEZY CONDITIONS TO THE COAST ON
THURSDAY. A COLD FRONT REACHES THE COAST THURSDAY AFTERNOON AND
SWEEPS INLAND THURSDAY NIGHT. HIGH POPS FOR BOTH THESE FRONTS.
FRIDAY MORNING COULD BE MOSTLY DRY WITH JUST SCATTERED SHOWERS BUT
YET ANOTHER SYSTEM ARRIVES FRIDAY AFTERNOON...AND HAVE KEPT LIKELY
POPS FOR THIS SYSTEM. TEMPERATURES WILL REMAIN SEASONAL WITH HIGHS
AROUND 50 AND LOWS AROUND 40. ONE EXCEPTION COULD BE THURSDAY WHEN
THE AREA WILL BE IN THE WARM SECTOR AFTER THE PASSAGE OF THE WARM
FRONT. ON THURSDAY SOME TEMPERATURES WILL REACH THE MID 50S. BURKE
.LONG TERM...AFTER ANOTHER LULL FRIDAY NIGHT AND SATURDAY MORNING...
MODELS BRING ANOTHER SYSTEM INTO THE PACIFIC NORTHWEST. THE EURO
SENDS MOST MOISTURE INTO BRITISH COLUMBIA AND THEN BRINGS A FRONT
THROUGH WASHINGTON ON SUNDAY. THE GFS BRINGS A MORE CONSOLIDATED
FRONT DIRECTLY THROUGH WASHINGTON SATURDAY NIGHT. NEITHER ONE
IS ALL THAT IMPRESSIVE WITH RAINFALL AMOUNTS...EVEN IN THE OLYMPIC
MOUNTAINS. THUS WILL OPT FOR NO STATEMENT ABOUT POTENTIAL FLOODING.
BOTH THE EURO AND GFS HAVE DRY SUNDAY NIGHTS AND MONDAYS AND WET
TUESDAYS. HAVE NOT COMPLETELY BOUGHT THESE SOLUTIONS AND KEPT THE
BROAD BRUSH LIKELY POPS FOR NOW. BURKE
&&
.HYDROLOGY...NOTHING TOO SIGNIFICANT IN THE MODELS THROUGH FRIDAY.
ANY RAIN WILL BE LIGHT TO MODERATE AND RIVERS WILL RISE ONLY
MODERATELY. THE MAIN EFFECT OF THE REPEATED RAIN STORMS WILL BE TO
MOISTEN THE SOIL AND GET THE HYDROLOGICAL SYSTEMS PRIMED AGAIN. BOTH
THE GFS AND EURO HAVE BACKED OFF SOMEWHAT ON RAINFALL AMOUNTS OVER
THE WEEKEND. MOST OF THE MOISTURE IS SHOVED NORTH INTO BRITISH
COLUMBIA. THERE IS STILL A CHANCE OF HEAVY RAIN OVER THE OLYMPIC
MOUNTAINS...ESPECIALLY ON SUNDAY. THE CASCADES DO NOT APPEAR TO BE
UNDER ANY THREAT AND THE PROBABILITY OF FLOODING ON THE GREEN RIVER
IS LOW.
POSSIBLY THE ONLY SIGNIFICANT EFFECT OF ALL THESE STORMS WILL BE TO
INCREASE THE THREAT OF LANDSLIDES IN SATURATED SOIL SLIGHTLY BY NEXT
WEEK. BURKE
&&
.AVIATION...HIGH PRES ALOFT WILL PERSIST THROUGH TONIGHT. MODERATE
SW FLOW ALOFT TONIGHT WILL BECOME STRONG ON WED. THE ATMOSPHERE WILL
BE DRY AND STABLE...BECOMING MOIST DURING THE DAY WED. RAIN WILL
DEVELOP LATE WED MORNING ALONG THE COAST...SPREADING INLAND BY WED
AFTERNOON AS A FRONT MOVE INTO WRN WA. THE COMBINATION OF BREEZY
WINDS AND CLOUDS SHOULD INHIBIT FOG DEVELOPMENT...EXCEPT THIS
EVENING AROUND THE SW INTERIOR AND STRAIT. THESE SPOTS SHOULD
IMPROVE LATER TONIGHT AS SOME MIXING DEVELOPS.
KSEA...VARIABLE WIND 4 KT OR LESS....BECOMING S 5-9 KT AFTER 08Z.
FOG IS UNLIKELY DUE TO SLY BREEZE AND INCREASING HIGH CLOUDS
TONIGHT. LIGHT RAIN AND CIGS 3-4K FT WILL DEVELOP AFTER 18Z THU.
&&
.MARINE...WIND GENERALLY LIGHT TONIGHT...EXCEPT E WIND UP TO 20 KT
AT THE W ENTRANCE TO THE STRAIT. A FRONT WILL BRING SOLID SMALL
CRAFT WINDS TO THE COASTAL WATERS AND W ENTRANCE WED MORNING THROUGH
THE AFTERNOON. WINDS WILL ALSO INCREASE FROM AROUND ADMIRALTY INLET
NWD LATER ON WED. A SMALL CRAFT MAY BE NEEDED FOR THESE AREAS. A
STRONGER FRONT BRINGS MORE WIDESPREAD SMALL CRAFT WINDS AND POSSIBLY
GALES TO THE COASTAL WATERS THU AND THU NIGHT.
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
PZ...SMALL CRAFT ADVISORY COAST AND WEST ENTRANCE WEDNESDAY MORNING
THROUGH WEDNESDAY AFTERNOON.
WA...NONE.
$$
WWW.WEATHER.GOV/SEATTLE
FOR AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION PLEASE SEE
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML (ALL LOWERCASE).
[
W WA |
SW WA and W OR |
SE WA and NE OR |
NE WA and N ID
]
Southwestern Washington and Western Oregon
059
FXUS66 KPQR 092246
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
246 PM PST TUE FEB 9 2010
.SYNOPSIS.. AN UPPER RIDGE REMAINS OVER THE AREA TONIGHT...THEN
MOVES EAST WEDNESDAY AS AN INCOMING SYSTEM MOVES ONSHORE IN THE
AFTERNOON... THEN THROUGH THE AREA WEDNESDAY NIGHT. AFTER WEDNESDAY
A SERIES OF SYSTEMS BRINGS RAIN TO THE AREA INTO NEXT WEEK. LOOK FOR
A WARM FRONT LIFTING NORTH THURSDAY...FOLLOWED BY A COLD FRONT
THURSDAY NIGHT...THEN ANOTHER SYSTEM FRIDAY.
&&
.SHORT TERM...LOW CLOUDS AND FOG ARE RAPIDLY CLEARING FROM THE SOUTH
WILLAMETTE VALLEY AND THE SOUTH COAST RANGE...OPENING THE DOOR FOR
MORE FOG FORMATION LATER TONIGHT AHEAD OF INCOMING CLOUDS. MODELS
MOVE A FRONT ONSHORE ALONG THE NORTH COAST LATE MORNING
WEDNESDAY...WITH PRECIPITATION SPREADING INLAND BY LATE AFTERNOON.
THE MODELS GENERALLY AGREE ON THE SYSTEM AND IT'S PROGRESSION THROUGH
LATE WED NIGHT. A WARM FRONT LIFTS NORTH OVER THE AREA THU MORNING
AND THAT'S WHEN MODELS BEGIN TO DIVERGE A BIT ON TIMING AND
PRECIPITATION AMOUNTS. THE THURSDAY SYSTEM IS WARM AND WET. THE GFS
TENDS TO SWING IT THROUGH THE NORTHWEST A LOT FASTER WITH MORE QPF...
WHEREAS THE ECMWF LIMITS PRECIPITATION MORE AS THE WARM FRONT
RUNS ABOUT 6 HOURS BEHIND THE GFS.
AN ASSOCIATED COLD FRONT MOVES THROUGH THE CWA THURSDAY NIGHT. SNOW
LEVELS REMAIN ABOVE THE PASSES AGAIN...FALLING TO NEAR PASS LEVEL
THURSDAY NIGHT AS PRECIPITATION ENDS. WINDY CONDITIONS WILL RETURN TO
THE COAST AS WELL...BUT WINDS WILL PROBABLY STAY BELOW HIGH WIND
CRITERIA. KWELSON
.LONG TERM...AN VERY WET AND ACTIVE WEATHER PATTERN WILL CONTINUE
THROUGH THE EXTENDED WITH SYSTEMS EVERY 24 TO 36 HOURS. INDIVIDUAL
SYSTEMS MOVE THROUGH THE FORECAST AREA RATHER QUICKLY. AFTER BRIEF
CLEARING LATE FRIDAY INTO SATURDAY A FRONTAL SYSTEM BRINGS RAIN TO
THE COAST AND INLAND SAT NIGHT INTO SUNDAY. THE NEXT SYSTEM WILL
ARRIVE LATE MONDAY. BROWN
&&
.AVIATION...AREAS OF MVFR CEILINGS IN THE CENTRAL AND S WILLAMETTE
VALLEY WILL CONTINUE TO DECREASE IN COVERAGE EARLY THIS EVENING BUT
SHOULD NOT COMPLETELY DISSIPATE. PATCHY TO AREAS IFR/MVFR ARE LIKELY
TO RETURN LATER TONIGHT BEFORE CLOUDS WITH THE NEXT FRONT ARRIVE.
EXPECT SOME MVFR CEILINGS WED AFTERNOON WITH THE FRONT ESPECIALLY
NEAR THE COAST.
KPDX AND APPROACHES...VFR THROUGH THIS EVENING. A 50 PCT CHANCE OF
IFR IN FOG RETURNING AROUND 11Z BUT WILL BE COMPETING WITH
INCREASING CLOUDS AHEAD OF THE NEXT FRONT.
&&
.MARINE...SEAS SHOULD REMAIN BELOW 10 FT WITH LIGHT WINDS THROUGH
WED. THE NEXT FRONTAL SYSTEM MOVES OVER THE WATERS BRINGING THE
POTENTIAL FOR MARGINAL GALES BY WED EVENING AND STRONGER GALES BY
THU AFTERNOON. SEAS WILL ALSO BE BUILDING ABOVE 10 FT. ADDITIONAL
FRONTAL SYSTEMS WILL TRACK INTO THE AREA FRI AND SAT CONTINUING A
MORE ACTIVE WEATHER PATTERN.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WATCH FROM CAPE SHOALWATER TO FLORENCE WED EVENING
THROUGH THU EVENING.
&&
&&
$$
[
W WA |
SW WA and W OR |
SE WA and NE OR |
NE WA and N ID
]
Southeastern Washington and Northeastern Oregon
455
FXUS66 KPDT 092230
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
230 PM PST TUE FEB 9 2010
.SHORT TERM...TONIGHT THROUGH FRIDAY...HIGH PRESSURE WILL DOMINATE
THE AREAS WEATHER WITH DRY CONDITIONS AND SOME PATCHY FOG OVERNIGHT
ACROSS PORTIONS OF THE LOWER COLUMBIA BASIN AND CENTRAL OREGON ALONG
WITH AND AROUND MEH. THE NEXT STORM SYSTEM OVER THE EPAC WAS POISED
TO STRIKE OUR AREA TOMORROW. ABUNDANT MOISTURE WILL STREAM INTO THE
TWO STATE AREA WITH SHOWERS DEVELOPING ACROSS THE EAST SLOPES OF THE
WA/OR CASCADES BY AFTERNOON. THE BULK OF THIS STORM SYSTEMS MOISTURE
IS EXPECTED TO SPREAD INTO THE REMAINDER OF OUR AREA WEDNESDAY
NIGHT. SNOW LEVELS WILL REMAIN HIGH BUT WILL BRIEFLY LOWER TOMORROW
NIGHT TO AROUND 4K AND SOME SNOW ACCUMULATION IS POSSIBLE OVER THE
BLUE MOUNTAINS AND CASCADES BY THURSDAY MORNING. OTHERWISE THE STORM
SYSTEM WILL MOVE EAST THURSDAY NIGHT AND PCPN SHOULD DECREASE ACROSS
THE AREA. AS THE SYSTEM MOVES EAST THURSDAY NIGHT BREEZY 850/MBS
WINDS MAY MIX TOWARD THE SURFACE THURSDAY EVENING ACROSS PORTIONS OF
THE COLUMBIA BASIN AND IN AND NEAR LGD. FINALLY A THIRD STORM SYSTEM
WILL BRING SHOWERS TO THE TWO STATE AREA FRIDAY.
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...A RIDGE OF HIGH PRESSURE
WILL START TO BUILD INTO THE PACIFIC NORTHWEST ON FRIDAY NIGHT.
THEREFORE...DRIER CONDITIONS CAN BE EXPECTED ON SATURDAY...BUT
MOUNTAIN SHOWERS COULD PERSIST DUE TO MOIST ONSHORE FLOW. A WEAK
FRONT WILL MOVE INTO THE REGION ON SUNDAY...BRINGING PRECIPITATION
TO MUCH OF THE AREA. HOWEVER...SNOW LEVELS WILL REMAIN HIGH ENOUGH
TO PRECLUDE SIGNIFICANT SNOW ACCUMULATIONS BELOW 5000 FEET. ANOTHER
TRANSITORY RIDGE WILL DEVELOP ON MONDAY...ALLOWING THE RAIN AND SNOW
SHOWERS TO DIMINISH. PROGRESSIVE WESTERLY FLOW WILL THEN SEND
ANOTHER WET WEATHER DISTURBANCE THROUGH THE REGION ON TUESDAY. WINDS
WILL GENERALLY BE LIGHT THROUGH THE PERIOD...BUT LOCALLY BREEZY
WINDS MAY DEVELOP AS EACH SYSTEM PASSES...ESPECIALLY IN THE GRANDE
RONDE VALLEY AND LADD/PYLES CANYONS. TEMPERATURES WILL REMAIN MILDER
THAN NORMAL. 82
&&
.AVIATION...18Z TAFS...VFR/MVFR CONDITIONS ARE EXPECTED TO PREVAIL
AT ALL TAF LOCATIONS. THERE MAY BE BRIEF PERIODS OF IFR OR LOWER DUE
TO FOG UNDER A PERSISTENT STRATUS LAYER...ESPECIALLY LATE
TONIGHT/WEDNESDAY MORNING. WINDS WILL BE LIGHT THROUGH THE
PERIOD...REMAINING LESS THAN 10 KTS. 82
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 31 48 36 48 / 0 10 40 50
ALW 30 48 35 46 / 0 10 40 40
PSC 30 47 35 49 / 0 10 40 40
YKM 29 46 31 45 / 10 30 50 40
HRI 32 48 37 49 / 0 10 40 40
ELN 29 44 30 42 / 10 30 50 40
RDM 26 49 34 52 / 10 30 60 50
LGD 25 41 31 45 / 10 10 40 60
GCD 28 44 32 49 / 10 10 50 50
DLS 33 49 36 50 / 10 40 60 50
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
WEDNESDAY : GREEN
THURSDAY : GREEN
FRIDAY : 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
$$
97/82/82
[
W WA |
SW WA and W OR |
SE WA and NE OR |
NE WA and N ID
]
Northeastern Washington and Northern Idaho
492
FXUS66 KOTX 100033 CCA
AFDOTX
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SPOKANE WA
434 PM PST TUE FEB 9 2010
.SYNOPSIS...WEAK HIGH PRESSURE OVER THE NORTHWEST WILL MAINTAIN
DRY BUT VARIABLY CLOUDY CONDITIONS TONIGHT THROUGH WEDNESDAY
MORNING. A STORM SYSTEM WILL SPREAD A CHANCE OF VALLEY RAIN AND
SNOW MIX AND MOUNTAIN SNOW OVER THE REGION WEDNESDAY AFTERNOON AND
WEDNESDAY NIGHT. A SERIES OF STORM SYSTEMS WILL HAVE THE POTENTIAL
TO BRING MOUNTAIN SNOW AND VALLEY RAIN TO THE NORTHWEST THROUGH
EARLY NEXT WEEK.
&&
.DISCUSSION...
TONIGHT AND WEDNESDAY...SATELLITE REVEALS THE FORECAST AREA IS
UNDER A WEAK RIDGE IN A SPLIT FLOW REGIME...WITH A DEEPLY WRAPPED
STORM SYSTEM MOVING INTO CALIFORNIA AND A WEAKER POLAR STORM TRACK
OVER BRITISH COLUMBIA. THE NEXT PACIFIC STORM SYSTEM IS VISIBLE
OFF THE COAST AND WILL OVERRUN THE REGION TOMORROW AFTERNOON AND
EVENING. GFS AND NAM MODELS ARE SIMILAR IN DEPICTING A WEAK RIDGE
HOLDING OVER THE REGION TONIGHT...WITH A CONTINUATION OF VARIABLY
CLOUDY CONDITIONS AND NO PRECIPITATION THREAT OUTSIDE OF A SLIGHT
FLURRY THREAT OVER THE MOUNTAINS NEAR THE CANADIAN BORDER. A HIGH
STRATUS DECK HAS PERSISTED UNDER THE RIDGE SUBSIDENCE INVERSION
OVER MUCH OF THE REGION THROUGH THE DAY TODAY...AND FIELDS OF THIS
HIGH STRATUS WILL LIKELY PERSIST THROUGH TONIGHT WITH NOTHING TO
KNOCK LOOSE THE SUB-INVERSION AIR MASS. THUS TONIGHT WILL BE AT
LEAST PARTLY TO MOSTLY CLOUDY...DRY AND FEATURE OVERNIGHT LOWS
SLIGHTLY ABOVE NORMAL GIVEN REDUCED OPPORTUNITY FOR RADIATIONAL
COOLING PRESENTED BY THE CLOUD COVER.
ON WEDNESDAY THE FRONTAL SYSTEM OFF THE COAST WILL SPREAD
THICKENING CLOUDS AND INCREASING CHANCES OF VALLEY RAIN AND
MOUNTAIN SNOW FROM WEST TO EAST DURING THE DAY...WITH MOST
LOCATIONS NORTH OF INTERSTATE 90 SUFFERING AT LEAST A SLIGHT
CHANCE OF PRECIPITATION BY LATE AFTERNOON...WITH THE BEST CHANCE
OVER THE WESTERN AND NORTHERN ZONES. /FUGAZZI
WEDNESDAY NIGHT THROUGH FRIDAY...A MILD...UNSETTLED PATTERN IS
IN STORE FOR THE PAC NW AS THE LONGWAVE PATTERN UNDERGOES A FEW
CHANGES INCLUDING SHIFTING THE LONGWAVE RIDGE AXIS
INLAND...ALLOWING THE GULF OF ALASKA LOW TO RECLAIM RESIDENCE
CLOSER TO THE COAST...AND RE-ESTABLISHING A DOMINATE MID LEVEL
SOUTHWESTERLY FLOW ACROSS THE REGION. THIS WILL ALLOW A DEEP FETCH
OF MOISTURE TO STREAM TOWARD THE REGION WITH A SERIES OF WEAK TO
MODERATE FRONTAL SYSTEMS TRACKING THROUGH EVERY 8 TO 15 HOURS
BRINGING PERIODS OF PRECIPITATION. IN GENERAL...THE MILD SW FLOW
WILL CONTINUE TO SUPPORT MAINLY VALLEY RAIN AND MTN SNOW.
AMSU SATELLITE SHOWS A DEEP FETCH OF MOISTURE WITH PWAT WELL
OVER ONE INCH STEMMING FROM THE SUBTROPICS NORTHEASTWARD TOWARD
50N 140W WRAPPING INTO A DEEP LOW PRESSURE SYSTEM WHICH IS BEING
DRIVEN EASTWARD UNDER A 175KT JET ALONG 40N. MODEL INITIALIZATION
IS PLAUSIBLE BUT IT APPEARS THE 12Z GFS IS A BIT QUICK AND DRY
WITH THIS FEATURE SO WILL TREND TOWARD THE SLOWER ECMWF IN REGARDS
TO TIMING OF INDIVIDUAL SHORTWAVE ENERGY THROUGHOUT THE PERIOD.
THIS MATCHES WELL WITH THE NAM. AS THE PATTERN SHIFTS EASTWARD
OVER THE NEXT 36 HOURS...THE MOIST TONGUE WILL NOSE INTO THE PAC
NW WITH PWATS ACROSS EASTERN WA INCREASING FROM NEAR 0.30"
CURRENTLY TO 0.50"- 0.75". THERE ARE TWO MAIN SHORTWAVES WE WILL
BE FOCUSING OUR ATTENTION ON...ONE COMING THROUGH WEDNESDAY NIGHT
INTO THURSDAY...THE SECOND ON FRIDAY. IN BTWN...SW FLOW WILL
PERSIST...KEEPING THE CHANCE FOR OROGRAPHIC SHWRS ONGOING
THROUGHOUT MTNS. THE FIRST WAVE WILL BE RIDE ALONG THE NORTHERN
PERIPHERY OF A FLAT RIDGE IN PLACE AND TAKE A TRACK ALONG THE
US/CANADIAN BORDER WITH THE BEST Q-VECTOR CONVERGENCE FOCUSING
ALONG SOUTHERN BRITISH COLUMBIA. IN THE WAKE OF WAVE ONE
(THURSDAY)...WE WILL SEE THE GULF OF ALASKA CLOSING IN ON THE
COAST AND THIS WILL ALLOW RIDGING TO BRIEFLY RE- AMPLIFY
DOWNSTREAM OVER THE PAC NW. HOWEVER THIS RIDGE AXIS WILL QUICKLY
SHIFT INLAND THURSDAY NT AND FRIDAY AS THE NEXT SHORTWAVE EJECTS
ACROSS THE PAC NW. I HAVE TO BELIEVE THIS WAVE WILL WEAKEN AND
SLOW DOWN WHILE RUNNING INTO THE RIDGE...TAKING SOMEWHAT OF A
NEGATIVE TILT. THEREFORE...AS MENTIONED ABV...WILL FOLLOW CLOSER
TO THE ECMWF/NAM WHICH PORTRAYS A STRONGER STRETCHING AND SLOWER
PASSAGE OPPOSED TO THE GFS.
ALL THINGS CONSIDERED...FIRST ROUND OF LIGHT PCPN TO COME
ACROSS THE REGION WEDNESDAY NT WITH ANOTHER THURSDAY INTO FRIDAY.
WE DO EXPECT SOME DRYING BTWN SYSTEMS...ROUGHLY THURSDAY MORNING.
THE STRONGEST DRYING SHOWS UP WITHIN THE 700-300MB LAYER WITH THE
SFC-850MB LAYER REMAINING SATURATED WITH 85H FLOW PERSISTING OUT
OF THE SW. WITH THE DRYING THROUGHOUT THE -10 TO -20 CELSIUS
LAYER...AND BL REMAINING SATURATED...I ANTICIPATE PCPN WILL CHANGE
OVER TO DRIZZLE; ESPECIALLY FOR MUCH OF NORTHERN IDAHO AND NE WA
INCLUDING UPPER COLUMBIA BASIN...BEFORE THE NEXT FRONTAL SYSTEM
ARRIVES THURSDAY AFTERNOON. ANOTHER DRY-SLOT SHOULD WORK WEST TO
EAST FRIDAY AFTN BRINGING ANOTHER SHORT-LIVED BREAK IN THE WEATHER
BEFORE A THIRD SYSTEM FRIDAY NT. THE EXACT TIMING IS SUBJECT TO
CHANGE SOME REGARDING THE HEAVIER PCPN CHANCES SO WILL LEAVE AT
LEAST CHC POPS IN PLACE AND FINE TUNE THINGS AS EACH WAVE BECOMES
A BIT MORE EVIDENT OVER THE NEXT 24 HRS.
THE COOLEST TEMPERATURES OF THE PERIOD WILL LIKELY BE WEDNESDAY NT
WHERE SOME CLEARING AND WET BULB COOLING IS EXPECTED PRIOR TO THE
ARRIVAL OF THE FIRST PCPN BANDS. THEREAFTER...A STEADY S/SW FLOW
REGIME WILL KEEP TEMPERATURES ABOVE NORMAL. SNOW LEVELS WILL
GENERALLY RESIDE NEAR 3000' NORTH TO 5000' SOUTH. /SB
FRIDAY NIGHT THROUGH TUESDAY...AN UPPER LOW IN THE GULF OF ALASKA
WILL SEND A SERIES OF SYSTEMS INTO THE AREA THROUGH EARLY NEXT
WEEK. THE PREVAILING FLOW ALOFT WILL BE OUT OF THE SOUTHWEST WHICH
WILL KEEP SNOW LEVELS HIGH ENOUGH TO SUPPORT RAIN IN THE VALLEYS
AND SNOW IN THE MOUNTAINS. TIMING OF SYSTEMS SUPPORTS THE HIGHEST
POPS FRIDAY NIGHT AND AGAIN ON SUNDAY...WITH NEAR CLIMO POPS FOR
THE OTHER FORECAST PERIODS. TEMPERATURES WILL REMAIN ABOVE NORMAL
THROUGH THE EXTENDED PERIOD. JW
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED TO PREDOMINATE THROUGH WED AFTERNOON.
LOCAL MVFR CIGS TO BELOW 3000 FT AGL WILL BE POSSIBLE THIS
MORNING WITH LOW CONFIDENCE THAT THIS WILL OCCUR AT ANY TAF SITE.
PATCHY FOG IS NOT OUT OF THE QUESTION AS WELL THIS MORNING AS
WINDS ARE EXPECTED TO REMAIN LIGHT...BUT LOW CONFIDENCE IN THIS
SCENARIO AS THE STRATUS DECK WILL LIMIT RADIATIONAL COOLING
OVERNIGHT. THE NEXT PACIFIC WEATHER SYSTEM WILL MOVE INTO THE
REGION SOMETIME BTWN 21-00Z WED AFTERNOON WITH -RA AT KEAT AND
KMWH AND UPSLOPE FLOW PRODUCING VCSH NEAR SPOKANE/COEUR D'ALENE.
/SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 31 42 32 42 36 43 / 10 20 50 60 70 30
COEUR D'ALENE 31 41 31 41 34 43 / 10 20 50 60 70 60
PULLMAN 32 45 33 46 37 46 / 10 10 60 60 50 40
LEWISTON 34 51 37 49 40 51 / 0 0 50 40 30 20
COLVILLE 30 40 31 40 34 43 / 10 50 40 60 70 60
SANDPOINT 30 39 30 39 34 41 / 10 40 50 60 70 60
KELLOGG 30 39 31 39 34 42 / 10 20 70 50 70 60
MOSES LAKE 32 45 34 43 37 48 / 0 30 20 50 50 20
WENATCHEE 31 40 31 40 35 46 / 0 40 20 50 50 20
OMAK 30 39 31 39 33 44 / 0 40 20 50 70 20
&&
.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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