[
W WA |
SW WA and W OR |
SE WA and NE OR |
NE WA and N ID
]
Western Washington
273
FXUS66 KSEW 071811 CCA
AFDSEW
AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SEATTLE WA
935 AM PST SAT NOV 7 2009
CORRECTED WATCH/WARNING/ADVISORY SEGMENT NEAR BOTTOM.
.SYNOPSIS...A BROAD UPPER LEVEL TROUGH WITH COOL MOIST UNSTABLE AIR
WILL CONTINUE TO DIRECT SHOWERS...THUNDERSTORMS AND BREEZY WEATHER
INTO WESTERN WASHINGTON THROUGH SUNDAY MORNING. A WARM FRONT WILL
MOVE THROUGH THE AREA SUNDAY NIGHT...FOLLOWED BY A COLD FRONT ON
MONDAY. A WEAKER COLD FRONT SHOULD CROSS THE AREA TUESDAY FOLLOWED
BY SHOWERS FROM AN UPPER LEVEL TROUGH ON WEDNESDAY. A WEAK UPPER
LEVEL RIDGE ON THURSDAY SHOULD LOWER THE CHANCE OF RAIN...BUT
ANOTHER FRONTAL SYSTEM WILL PROBABLY REACH THE AREA FRIDAY OR
SATURDAY.
&&
.SHORT TERM...A BROAD UPPER TROUGH WILL CONTINUE OVER THE ERN PAC
INTO THE MIDDLE OF NEXT WEEK. THIS TYPICALLY SPELLS ACTIVE AND
UNSETTLED WEATHER FOR THE PAC NW.
FOR TODAY...SATELLITE IMAGERY STILL SHOWS A LOT OF COLD CONVECTIVE
CLOUD TOPS FOR A LONG DISTANCE UPSTREAM OFF THE COAST...ALLOWING THE
COLD AND CONVECTIVE PATTERN TO CONTINUE THROUGH TONIGHT AND INTO
SUNDAY MORNING. VERY COLD AIR ALOFT (500 MB TEMPS AT OR BELOW -30C)
CONTINUES TO SUPPORT AN UNSTABLE ATMOSPHERE ALONG WITH SHOWERS AND
SCATTERED THUNDERSTORMS. WITH SNOW LEVELS AROUND 3000 FEET...THIS
WILL EQUATE TO BURSTS OF HEAVY SNOW IN THE MOUNTAINS...WHERE A
WINTER STORM WARNING IS IN EFFECT. COLD AIR ALOFT WILL CONTRIBUTE TO
GENEROUS SNOW RATIOS...AGAIN SUPPORTING THE NOTION OF HEAVY SNOW IN
THE MTNS. LOOKS LIKE A SHORTWAVE IS CURRENTLY SPREADING ACROSS WRN
WA...ENHANCING LIFT AND CONVECTION. UNLIKE EARLY YESTERDAY AFTERNOON
WHEN THERE WERE SEVERAL DISCRETE CELLS ON RADAR...SOME WITH
ROTATION...PRECIP ON RADAR RIGHT NOW LOOKS A LITTLE MORE SPREAD OUT
WITHOUT SO MANY DISCRETE CELLS. COLD AIR ALOFT AND DEPTH OF THE
CONVECTION WILL CONTINUE TO SUPPORT PROLIFIC AMOUNTS OF SMALL HAIL
IN THUNDERSTORMS.
LOOKS LIKE A SHORTWAVE DROPPING INTO THE BACK SIDE OF THE ERN PAC
TROUGH WILL AMPLIFY THE LONGWAVE PATTERN A BIT LATER SUNDAY. THIS
WILL TURN THE FLOW ALOFT MORE SOUTHERLY ON SUNDAY NIGHT. AT
FIRST...A WEAK WARM FRONT WILL LIFT ACROSS THE AREA ON SUNDAY NIGHT.
CONSIDERING THE CURRENT ATMOSPHERIC INSTABILITY...THE ADDED
STABILITY MAY ACTUALLY DO MORE TO INHIBIT PRECIP THAN WILL BE ADDED
BY ISENTROPIC LIFT. STILL...LOWERING OF POPS OVER THE INTERIOR INTO
THE CHANCE CATEGORY LATE SUN NIGHT IS APPROPRATE. A COLD FRONT WILL
THEN MOVE INLAND LATER ON MONDAY AND EAST OF THE CASCADES ON MON
NIGHT...BRINGING ANOTHER ROUND OF MODERATE TO HEAVY RAIN FOR SEVERAL
HOURS. HANER
.LONG TERM...FROM PREVIOUS DISCUSSION...GFS AND ECMWF REMAIN IN GOOD
AGREEMENT REGARDING THE OVERALL PATTERN THROUGH THE END OF NEXT
WEEK...BUT AFTER WEDNESDAY BEGIN DIVERGING ON TIMING...WITH THE GFS
FASTER. THE OVERALL PATTERN REMAINS PROGRESSIVE AS THE PARADE
CONTINUES. MODELS HAVE GOOD AGREEMENT WITH ANOTHER COLD FRONT
TUESDAY...FOLLOWED BY AN UPPER LEVEL TROUGH WEDNESDAY. MINOR BREAK
THURSDAY WITH A RIDGE BRIEFLY OVERHEAD...BUT THE GFS KEEPS SOME
LIGHT PRECIP IN THE AREA. ANOTHER FRONTAL SYSTEM ARRIVES EITHER
FRIDAY OR FRIDAY NIGHT. KAM
&&
.HYDROLOGY...NO SIGNIFICANT FLOODING IS EXPECTED IN WESTERN
WASHINGTON DURING THE NEXT WEEK. THIS INCLUDES THE GREEN RIVER.
FOR THIS WEEKEND...SNOW LEVELS OF 2500 TO 3000 FEET WILL ELIMINATE
THE POTENTIAL FOR EXCESSIVE RUNOFF OVER MOUNTAIN HEADWATERS. SNOW
LEVELS WILL RISE TO NEAR 5000 FEET IN ADVANCE OF A WET COLD FRONT ON
MONDAY...BUT THE FRONT WILL BE MOVING QUICKLY...LIMITING THE
DURATION OF HEAVY RAINFALL. LIMITED DURATION TENDS TO REDUCE THE
RISK OF EXCESSIVE RUNOFF. MORE PRECIPITATION IS EXPECTED ON TUESDAY
AND WEDNESDAY...BUT SNOW LEVELS WILL AGAIN BE BACK DOWN NEAR 3000
FEET. DRY WEATHER IS POSSIBLE ON THURSDAY AND FRIDAY BEFORE ANOTHER
WET BUT FAST-MOVING COLD FRONT ARRIVES EARLY NEXT WEEKEND.
AGAIN...THE RISK OF MAINSTEM RIVER FLOODING DURING THE NEXT WEEK IS
VERY LOW. HANER
&&
.AVIATION...UNSETTLED WEATHER WILL CONTINUE ACROSS WESTERN
WASHINGTON TODAY. A STRONG UPPER LEVEL LOW CONTINUES TO SPIN OFF OF
THE ALASKA PANHANDLE WITH CYCLONIC FLOW ALOFT ACROSS THE PACIFIC
NORTHWEST. IR SATELLITE SHOWS AN EXTENSIVE CUMULUS FIELD OVER THE
OCEAN DRIFTING INLAND. A BAND OF SHOWERS IS MOVING THROUGH THE PUGET
SOUND AREA THIS MORNING. AN UPTICK IN ACTIVITY IS ANTICIPATED THIS
AFTERNOON AS A SURFACE TROUGH MOVES INLAND. SCATTERED THUNDERSTORMS
WILL BE POSSIBLE ALONG WITH SMALL HAIL...SOME LIGHTNING ALREADY
ALONG THE COAST. SHOWERS WILL DECREASE TONIGHT. CEILINGS WILL RANGE
FROM NO CEILING TO MVFR IN SHOWERS...INCLUDING MVFR VISIBILITY.
KSEA...SEE ABOVE...NO REASON TO THINK KSEA WILL BE DIFFERENT. GUSTY
SOUTH WINDS 10-20 KT WITH GUSTS TO 30 KT...BECOMING MORE SOUTHWEST
IN THE AFTERNOON. WINDS EASE TONIGHT. CHB
&&
.MARINE...GALE WARNING POSTED FOR COAST AS MARGINAL GALE SEEMS
LIKELY. SMALL CRAFT ADVISORY SOUTHWEST WINDS WILL CONTINUE THE REST
OF TODAY AND INTO THE EVENING AND HAVE EXTENDED THE END TIME OF THE
ADVISORIES UNTIL MIDNIGHT TONIGHT. THERE WILL BE SOMETHING OF A
LULL...INLAND AT LEAST...ON SUNDAY AS WASHINGTON IS BETWEEN SYSTEMS.
NEXT SYSTEM SUNDAY NIGHT AND MONDAY LOOKS LIKE A STRONG GALE ON THE
COAST AND AT THE WEST ENTRANCE...POSSIBLY PUSHING STORM FORCE WINDS.
GALES MOST OTHER WATERS INDICATED AS WELL. FRONT PASSES MONDAY
AFTERNOON FOR A BURST OF WESTERLIES DOWN THE STRAIT. PATTERN OF LOW
PRES OFFSHORE WITH SE WINDS QUICKLY RESUMES AS ONE SYSTEM AFTER
ANOTHER MOVES TOWARD WASHINGTON.
MEANWHILE...LARGE WESTERLY SWELLS UP TO 25 FT CONTINUE ACROSS THE
COASTAL WATERS TODAY...WILL CONTINUE THE HIGH SURF WARNING FOR THE
BEACHES. SWELLS WILL GRADUALLY DECAY TO 20 FT ON SUN. CHB
&&
.SEW WATCHES/WARNINGS/ADVISORIES...
WA...WINTER STORM WARNING FOR THE CENTRAL AND NORTH CASCAES UNTIL
4 AM PST SUNDAY.
WINTER WEATHER ADVISORY FOR THE OLYMPICS UNTIL 10 PM PST
TONIGHT.
HIGH SURF WARNING FOR THE COAST THROUGH 4 PM TODAY.
PZ...GALE WARNING COAST.
SMALL CRAFT ADVISORY ALL OTHER WATERS.
SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.
$$
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
127
FXUS66 KPQR 071659
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
859 AM PST SAT NOV 7 2009
.SYNOPSIS...A COOL SHOWERY AIR MASS WILL CONTINUE TO SPREAD INTO THE
PACIFIC NORTHWEST THROUGH EARLY TONIGHT. THE AIR MASS WILL ALSO
CONTINUE TO BE RATHER UNSTABLE FOR A THREAT OF THUNDERSTORMS
ESPECIALLY NEAR THE COAST. THE SHOWERS ARE EXPECTED TO TAPER OFF ON
SUNDAY IN THE SOUTH...WHILE A WEAK SYSTEM MAY BRUSH THE NORTHERN
AREAS. A RATHER STRONG COLD FRONT WILL MOVE THROUGH MONDAY AFTERNOON
AND EVENING WITH MORE RAIN...MOUNTAIN SNOW AND BRISK WINDS.
&&
.SHORT TERM...A COOL UNSTABLE WESTERLY FLOW ALOFT WILL CONTINUE TO
MOVE INTO THE REGION TODAY THROUGH THIS EVENING...WITH EMBEDDED
DISTURBANCES ENHANCING THE SHOWERS AT TIMES. THE LEADING PORTION OF
ONE SUCH BAND IS CURRENTLY MOVING ONTO THE COAST WITH TSTMS SHOWING
ON LIGHTNING DETECTORS...RADAR AND THE ASTORIA METAR. SHEAR PROFILES
LOOK SIMILAR TO OVERNIGHT...NOT A LOT OF DIRECTIONAL SHEAR BUT GOOD
SPEED SHEAR...AND THUS THE TSTMS NEAR THE COAST TODAY COULD AGAIN BE
ON THE STRONGER SIDE. THIS DISTURBANCE TRAILS OFF TO THE SW AND DOES
NOT APPEAR TO CLEAR OUR FORECAST AREA UNTIL SOME TIME THIS
EVENING...AFTER WHICH THE SHOWERS SHOULD EASE. AS A RESULT...THE
WINTER WEATHER ADVISORY FOR THE CASCADES CONTINUES TO LOOK GOOD
THROUGH THE 10 PM TERMINATION TIME. SNOW LEVELS WILL BE AROUND 3000
TO 3500 FEET TODAY AND TONIGHT.
THE UPPER FLOW BEGINS TO BUCKLE AND BACK SUN AND MON AS THE
NEXT FRONTAL SYSTEM DEVELOPS OFF THE COAST. THE MODELS SAY SOME SORT
OF WARM ADVECTION PRECIPITATION MAY AFFECT AT LEAST THE NW PART OF
OUR AREA SUN...ALTHOUGH THE GFS MAINTAINS AN UNSTABLE AIR MASS NEAR
THE COAST. THIS ACTIVITY THEN LIFTS N SUN NIGHT FOR DRYING. THE
ASSOCIATED STRONG COLD FRONT WILL MOVE IN MON AFTERNOON AND MOVE E
MON NIGHT. THIS FRONT SHOULD PRODUCE GALES AGAIN ALONG THE COAST WITH
GUSTY WINDS ALONG THE COASTAL STRIP...AND BREEZY CONDITIONS INLAND.
SNOW LEVELS LIFT SOME AHEAD OF THIS FRONT...SO WE WILL HAVE TO SEE IF
THEY LOWER SOON ENOUGH TO GET ENOUGH SNOW FOR ANOTHER WINTER WEATHER
ADVISORY IN THE CASCADES. RIGHT NOW IT IS LOOKING RATHER IFFY.
RW/TOLLESON
.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...SNOW LEVELS
WILL START FALLING AGAIN MONDAY NIGHT AS THE NEXT STRONG FRONTAL
SYSTEM MOVES ACROSS THE CASCADES AND THE COOL UPPER LEVEL TROUGH
MOVES IN BEHIND IT. SHOWERY WEATHER WITH SNOW LEVELS BETWEEN 3000
AND 4000 FT WILL PERSIST THROUGH WEDNESDAY MORNING. EXTENDED MODELS
ARE CURRENTLY SHOWING THE UPPER LEVEL TROUGH WEAKENING OUT ON
WEDNESDAY TO BE REPLACE BY A RIDGE ON THURSDAY AND FRIDAY. IF THIS
TREND HOLDS TRUE DRIER WEATHER IS POSSIBLE FOR A COUPLE OF DAYS.
RUTHFORD.
&&
.AVIATION...MOSTLY VFR TODAY EXCEPT LOCAL MVFR/IFR CIGS/VSBYS AND
SMALL HAIL POSSIBLE IN SHOWERS AND THUNDERSTORMS AS WEAK FRONT MOVES
THROUGH. THIS FRONT IS ALREADY MOVING ONSHORE AT KAST AND WILL MOVE
SE ACROSS THE AREA THROUGH THE DAY. SOME GUSTY WINDS OF UP TO 35 KT
ARE POSSIBLE IN SOME OF THE STRONGER CELLS.
KPDX AND APPROACHES...MAINLY VFR...BRIEF MVFR CIGS/VSBYS AND GUSTY
WINDS UP TO 35 KT POSSIBLE IN SHOWERS/ISOLATED THROUGH THIS EVENING.
STRONGEST CELLS ARE LIKELY TO MOVE THROUGH THE PDX AREA BETWEEN 18Z
AND 00Z...AS COLD FRONT PRESENTLY NEAR KAST MOVES SLOWLY MOVES SE
ACROSS THE DISTRICT. BRIEF SMALL HAIL IS ALSO POSSIBLE WITH THE
HEAVIER CELLS. WEAGLE
&&
.MARINE...MAIN CONCERN TODAY WILL BE THE VERY LARGE SEAS AND GUSTY
WINDS ASSOCIATED WITH SQUALLY WEATHER TODAY ACROSS THE COASTAL
WATERS. SEAS OF 23-27 FT WILL IMPACT THE COASTAL WATERS THROUGH THIS
AFTERNOON...THEN VERY GRADUALLY SUBSIDE TONIGHT THROUGH EARLY NEXT
WEEK. A COLD FRONT THIS AFTERNOON SHOULD BRING BRIEF GALES TODAY.
ANOTHER GOOD CHANCE FOR GALES WITH A STRONGER FRONT ANTICIPATED LATE
SUN NIGHT/MON. WEAGLE
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
WA/OR...GALE WARNING FROM CAPE SHOALWATER TO FLORENCE OUT 60 NM
TODAY.
HIGH SURF WARNING SOUTH WASHINGTON...NORTH AND CENTRAL
OREGON COAST TODAY.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR IN
EFFECT THROUGH SUNDAY.
WINTER WEATHER ADVISORY FOR SNOW FOR THE SOUTH
WASHINGTON AND THE NORTH AND CENTRAL OREGON CASCADES
CONTINUES THROUGH 10 PM TONIGHT.
&&
$$
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
378
FXUS66 KPDT 072230 AAA
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
230 PM PST SAT NOV 7 2009
.SHORT TERM...TONIGHT THROUGH TUESDAY...BREEZY CONDITIONS WILL
CONTINUE THIS EVENING AS ANOTHER DISTURBANCE PUSHES ACROSS THE AREA.
CLOUD COVER WILL CONTINUE TO INCREASE OVER THE NEXT SEVERAL HOURS
AND SHOWER ACTIVITY SHOULD REDEVELOP LATER THIS EVENING ACROSS THE
LOWER COLUMBIA BASIN EASTWARD. SNOW ACCUMULATIONS WITH THIS SYSTEM
ARE EXPECTED TO BE 1 TO 3 INCHES ACROSS THE BLUE MOUNTAINS. EXPECT
LINGERING SHOWER ACTIVITY TOMORROW ACROSS THE MOUNTAINS OF EASTERN
OREGON AND THE CASCADE CREST. ANOTHER WEATHER DISTURBANCE WILL DIP
DOWN FROM THE GULF OF ALASKA TOMORROW NIGHT. FLOW WILL SHIFT FROM
WEST TO SOUTHWEST AS A BRIEF RIDGE DEVELOPS OVER THE IDAHO...MONTANA
AREA MONDAY. WARM SOUTHERLY FLOW SHOULD KEEP MAX AND MIN TS MONDAY
AND TUESDAY NEAR TO SLIGHTLY ABOVE NORMAL. EXPECT THE NEXT WAVE OF
PRECIPITATION TO OCCUR MONDAY EVENING AHEAD OF THE FRONT...AND WITH
WAA...EXPECT MAINLY RAIN SHOWERS ACROSS THE MOUNTAINS OF EASTERN
OREGON AND A RAIN SNOW MIX IN THE HIGHER ELEVATIONS. AT THE SAME
TIME...COLDER AIR WILL PUSH ACROSS THE CASCADES LOWERING THE SNOW
LEVELS. SNOW ACCUMULATIONS ALONG THE CASCADE CREST SHOULD BE AN
INCH OR TWO. WEBER
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY NIGHT...MODELS ARE IN
GOOD AGREEMENT THROUGH THE LONG TERM PERIOD. A FRONT WILL ARRIVE
TUESDAY NIGHT AND BRING RAIN SHOWERS WITH SNOW ABOVE 3500 FEET IN
THE CASCADES AND 4500 FEET IN THE EASTERN MOUNTAINS. A TROUGH WILL
DEVELOP OVER THE AREA AND SNOW LEVELS WILL LOWER WEDNESDAY DOWN TO
3000 TO 3500 FEET AS RAIN AND SNOW SHOWERS CONTINUE OVER THE WHOLE
AREA. ANOTHER SYSTEM WILL ARRIVE WEDNESDAY NIGHT AND BRING ANOTHER
ROUND OF RAIN AND SNOW THROUGH THURSDAY. THIS SYSTEM WILL HAVE MORE
COLD AIR AND THE CASCADES WILL SEE SNOW LEVELS DOWN TO 2000 TO 2500
FEET WHICH WOULD IMPACT MOUNTAIN PASSES IN THE WASHINGTON CASCADES.
BRIEF RIDGING WILL MOVE IN THURSDAY NIGHT AND FRIDAY FOR A BREAK IN
THE PRECIPITATION ASIDE FROM LINGERING MOUNTAIN SHOWERS. YET ANOTHER
SYSTEM WILL ARRIVE SATURDAY FOR RAIN AND MOUNTAIN SNOW THROUGH
SATURDAY NIGHT. COOL TEMPERATURES ARE EXPECTED WITH DAYTIME
TEMPERATURES IN THE MID 40S TO LOWER 50S WITH THE UPPER 30S TO MID
40S IN THE MOUNTAINS. PERRY
&&
PREVIOUS AVIATION DISCUSSION...18Z TAFS...VFR CONDITIONS WILL BE
PREVALENT FOR THE NEXT 24 HOURS. A WEATHER SYSTEM WILL CROSS THE
AREA LATE THIS AFTERNOON AND TONIGHT WITH RAIN SHOWERS ACROSS THE
REGION THROUGH 08/12Z. LOCALIZED AREAS OF MVFR CONDITIONS DUE TO
LOWERED CEILINGS AND VISIBILITIES WILL BE POSSIBLE NEAR THE HEAVIER
SHOWERS. BREEZY CONDITIONS ARE EXPECTED THIS AFTERNOON AND EVENING
WITH WINDS OF 10 TO 20 KTS WITH GUSTS TO 30 KTS THROUGH 08/06Z.
WINDS WILL DECREASE TO BELOW 15 KTS AFTER 08/06Z. PERRY
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 37 53 37 55 / 50 10 10 10
ALW 41 53 38 54 / 60 20 10 10
PSC 39 54 36 53 / 60 20 0 10
YKM 32 49 32 47 / 40 20 10 20
HRI 37 53 36 54 / 50 10 0 10
ELN 31 46 32 46 / 40 20 10 20
RDM 30 49 30 52 / 20 10 10 10
LGD 36 48 32 50 / 40 10 0 10
GCD 28 47 32 51 / 40 10 0 10
DLS 37 51 35 49 / 40 20 10 20
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
SUNDAY : GREEN
MONDAY : GREEN
TUESDAY : 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
$$
89/83/83
[
W WA |
SW WA and W OR |
SE WA and NE OR |
NE WA and N ID
]
Northeastern Washington and Northern Idaho
815
FXUS66 KOTX 072227
AFDOTX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPOKANE WA
227 PM PST SAT NOV 7 2009
.SYNOPSIS...
ANOTHER PACIFIC FRONTAL SYSTEM WILL BRING VALLEY RAIN AND POSSIBLY
HEAVY MOUNTAIN SNOW TO THE REGION TONIGHT. A TRAIN OF MODERATELY
STRONG STORMS AND FRONTS WILL CONTINUE TO PASS THROUGH THE REGION
THROUGH MOST OF NEXT WEEK. IN GENERAL THESE STORMS WILL PRODUCE
MOUNTAIN SNOW...WHILE IN THE VALLEYS DAYTIME STORMS WILL FEATURE
RAIN...AND OVERNIGHT STORMS BY THE MIDDLE OF NEXT WEEK WILL ALLOW
SOME LIGHT SNOW TO REACH DOWN TO VALLEY FLOORS.
&&
.DISCUSSION...
...MORE ACTIVE WEATHER IN STORE FOR THE INLAND NORTHWEST WITH
WINTER STORM HIGHLIGHTS REMAINING FOR THE NORTHEAST WASHINGTON AND
PANHANDLE MOUNTAINS THROUGH TONIGHT...
TONIGHT...THE INLAND NORTHWEST IS UNDER A BROAD TROUGH ALOFT AND A
SWIFT JET DIVING SOUTH OF THE REGION. A SERIES OF SHORTWAVES HAVE
BEEN WHIPPING THROUGH THE REGION ALONG THIS JET STREAM. THE
ATMOSPHERE HAS BEEN AND CONTINUES TO BE UNSTABLE...LEADING TO
INCREASED SHOWER DEVELOPMENT AS EACH WAVE PASSES. THE MODELS HAVE
BEEN STRUGGLING WITH THE TIMING OF THESE FEATURES...AND BELIEVE
SATELLITE AND RADAR ARE THE BEST TOOLS FOR THE NEAR TERM WEATHER.
CURRENTLY...A POTENT SHORTWAVE IS HAMMERING THE WEST SIDE OF
WASHINGTON WITH A BAND OF HEAVY RAINFALL...AND HEAVY SNOW FOR THE
CASCADES. THIS WAVE WILL PUSH ACROSS THE CASCADES AND INTO THE
IDAHO PANHANDLE OVERNIGHT...DRAGGING THE BAND OF SHOWERS WITH IT.
ANTICIPATE SOME DOWN SLOPE CONDITIONS...BUT THE SHOWERS WILL BECOME
MORE WIDESPREAD OVER THE EXTREME EASTERN WASHINGTON AND THE
PANHANDLE. BREEZY SOUTHWEST SURFACE FLOW ACROSS THE REGION WILL
SLACKEN AS THE SHOWERS INCREASE AND IR SATELLITE COOLING OF THE CLOUD
TOPS. ANTICIPATE THE MAIN BAND OF SHOWERS MOVING THROUGH EASTERN
WASHINGTON EARLY THIS EVENING...AND LINGERING IN THE PANHANDLE
OVERNIGHT WITH SNOW LEVELS 3500-4K FT. THIS WILL BE THE SECOND
ROUND OF SNOW FOR THE MOUNTAINS AS DEFINED IN THE CURRENT WINTER
STORM WARNINGS.
SUNDAY...THE WAVE EXITS THE PANHANDLE EARLY SUNDAY MORNING AND
OROGRAPHIC SHOWERS WILL LINGER THROUGH MIDDAY. MEANWHILE
UPSTREAM...SHORTWAVE RIDGING WILL DEVELOP AS A SURFACE LOW NEARS
VANCOUVER ISLAND. THIS WILL SEND A WARM FRONT ACROSS WASHINGTON
AND REACHING EAST OF THE CASCADES SUNDAY AFTERNOON. ISENTROPIC
LIFTS INCREASES DURING THE DAY AS THE ATMOSPHERE STABILIZES....WARMS
ALOFT AND MOISTURE INCREASES. ANTICIPATING THICKENING CLOUDS DURING
THE DAY AND LIGHT RAIN AND MOUNTAIN SNOW DEVELOPING FROM MIDDAY
ONWARD FOR THE NORTHWEST AND NORTHERN TIER ZONES. DESPITE THE
WARMING ALOFT AND SLOWLY RISING SNOW LEVELS...SURFACE TEMPERATURES WILL
BE SUBJECTED TO WET BULB COOLING FROM THE RAINFALL AND COOLER
TEMPERATURES THAN TODAY ARE ANTICIPATED. /RFOX.
SUNDAY NIGHT THROUGH TUESDAY...THE NAM/GFS/EC AND UK MODELS ALL
INDICATE A CONTINUING PROGRESSIVE FLOW PATTERN FEATURING MODERATE
STRENGTH AND RATHER FAST MOVING FRONTAL SYSTEMS...PUNCTUATED BY
SHORT DRY BREAKS BETWEEN STORMS. TIMING THESE WAVES AND BREAKS IS
THE MAIN CHALLENGE. THUS WHILE CONFIDENCE IS HIGH FOR AN ACTIVE
AND UNSETTLED AUTUMN WEATHER PATTERN...CONFIDENCE IS LESS FOR
NAILING DOWN THE TIMING OF THE INCOMING SYSTEMS. THE IMMINENT
FORECAST PACKAGE REFLECTS THE LATEST CONSENSUS TIMING OF A NUMBER
OF COMMONLY USED MODELS...WHICH ARE AT LEAST PLAUSIBLE WHEN
COMPARED TO SATELLITE EXTRAPOLATION. THE FAST AND PROGRESSIVE
NATURE OF THE INCOMING FLOW PATTERN SUGGESTS A POSSIBILITY THAT
TIMING OF THESE WAVES AND FRONTS MAY PROVE TO BE 6 TO 12 HOURS TOO
FAST OR SLOW AS SUBSEQUENT RUNS REFINE THE FLOW FIELD.
SUNDAY EVENING WILL BRING A DRYING TREND TO THE REGION AS THE
AFOREMENTIONED WARM FRONT MOVES OUT OF THE REGION ALLOWING WEAK
HIGH PRESSURE TO TAKE OVER. THIS BREAK WILL BE SHORT LIVED AS
ANOTHER WAVE PLOWS INTO THE REGION SPREADING THICKENING CLOUDS
OVER THE FORECAST AREA MONDAY...WITH A MOIST FRONTAL PASSAGE
MONDAY NIGHT ACROSS THE REGION. SNOW LEVELS WILL STILL BE HIGH
ENOUGH TO KEEP SNOW OUT OF THE VALLEYS WITH THIS FRONT...BUT THERE
IS HIGH CONFIDENCE THAT MOST LOCATIONS WILL EXPERIENCE A FEW
TENTHS OF PRECIPITATION WITH THIS WAVE. ON TUESDAY ANOTHER SHORT
WAVE RIDGE WILL ALLOW BRIEF DRYING BEFORE YET ANOTHER DISTURBANCE
ENCROACHES N THE REGION. /FUGAZZI
TUESDAY NIGHT THROUGH SATURDAY...THE REGION WILL REMAIN IN A COOL
AND UNSETTLED WEATHER PATTERN THROUGH THURSDAY AS A PACIFIC FRONTAL
SYSTEM AND COLD UPPER LOW WILL TRACK THROUGH THE INLAND NORTHWEST.
TUESDAY NIGHT ONE SYSTEM WILL BE EXITING TO OUR EAST WHILE THE NEXT
ONE APPROACHES FROM THE WEST. THE GREATEST THREAT FOR SHOWERS WILL
BE OVER THE HIGHER ELEVATIONS. ON WEDNESDAY A COLD FRONTAL PASSAGE
WILL KEEP SHOWERS ACROSS THE FORECAST AREA. THE HIGHEST POPS WILL BE
ACROSS THE EASTERN MOUNTAINS WHERE UPSLOPE FLOW WILL COMBINE WITH
WRAP AROUND MOISTURE AND A TROWEL FEATURE EVIDENT IN 700MB THETA E
CONTOURS. THIS THETA E RIDGE POKES INTO THE NORTHERN PANHANDLE AND
NE MTS OF WA. THERE IS THE POTENTIAL FOR SIGNIFICANT SNOWFALL IN THE
HIGHER ELEVATIONS ACROSS THE NORTHEAST ZONES WEDNESDAY NIGHT. SNOW
LEVELS DROP TO AROUND 2000-2500 FT BEHIND THE COLD FRONT. SCATTERED
SHOWERS WILL CONTINUE ON THURSDAY AS THE UPPER TROUGH AND -35C COLD
POOL AT 500MB TRACK OVERHEAD. SHOWERS WILL DIMINISH THURSDAY NIGHT AS
MID LEVEL RIDGING COMMENCES. MEDIUM RANGE MODELS ARE IN BETTER
AGREEMENT ON A COOL BUT DRY DAY FRIDAY. ANOTHER WET SYSTEM WILL
AFFECT THE REGION FOR THE WEEKEND. TEMPERATURES WILL TREND NEAR OR
SLIGHTLY BELOW SEASONAL NORMALS. /KELCH
&&
.AVIATION...
MOST OF THE TAF SITES ARE IN BETWEEN SYSTEMS ATTM WITH LINGERING
MVFR STRATUS AT KCOE. BREEZY SOUTHWEST WINDS WILL STRETCH FROM
KPSC TO KGEG FOR MUCH OF THE DAY...BUT ANTICIPATE LOCAL GUSTY
WINDS ACROSS MANY OF THE TAF SITES BETWEEN 21Z-02Z. ANOTHER
SHORTWAVE WILL MOVE FROM WESTERN WASHINGTON...ACROSS THE FORECAST
AREA THIS AFTERNOON AND USHER IN ANOTHER BAND OF SHOWERS. THESE
SHOWERS WILL MARCH FROM THE LEE OF THE CASCADES AND OKANOGAN
VALLEY BY 20Z...ACROSS THE BASIN TO THE KGEG-KCOE AND KPUW AREA
AFTER 23Z. ANTICIPATE LOCAL MVFR CIGS AND MOUNTAIN OBSCURATIONS
WITH THE SHOWERS AND SNOW LEVELS 3K-3500 FT. ANOTHER ROUND OF RAIN
WILL PUSH UP SOUTH BY MIDDAY SUNDAY WITH AN INCOMING WARM FRONT.
/RFOX.
&&
.PRELIMINARY POINT TEMPS/POPS...
SPOKANE 34 42 33 47 37 45 / 80 60 20 0 60 30
COEUR D'ALENE 35 43 32 47 36 45 / 80 50 20 0 70 40
PULLMAN 35 47 34 53 38 48 / 70 40 10 0 60 20
LEWISTON 40 52 37 55 43 55 / 50 20 10 0 30 20
COLVILLE 34 45 38 46 35 46 / 90 60 20 10 80 40
SANDPOINT 36 43 35 43 35 42 / 90 50 20 0 70 40
KELLOGG 33 41 30 45 36 40 / 100 80 20 10 60 50
MOSES LAKE 34 48 34 48 35 50 / 60 50 10 10 60 10
WENATCHEE 36 45 37 43 38 48 / 30 50 10 20 60 10
OMAK 31 45 37 44 34 46 / 70 60 20 20 80 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...WINTER STORM WARNING UNTIL 4 AM PST SUNDAY ABOVE 3500 FEET FOR
NORTHERN PANHANDLE.
WINTER STORM WARNING UNTIL 6 AM PST SUNDAY ABOVE 4000 FEET FOR
CENTRAL PANHANDLE MOUNTAINS.
WA...WINTER STORM WARNING UNTIL 4 AM PST SUNDAY ABOVE 3500 FEET FOR
NORTHEAST MOUNTAINS.
&&
$$
[
W WA |
SW WA and W OR |
SE WA and NE OR |
NE WA and N ID
]
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