[ W WA | SW WA and W OR | SE WA and NE OR | NE WA and N ID ]

Western Washington


621 
FXUS66 KSEW 222222
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
322 PM PDT FRI MAY 22 2015

.SYNOPSIS...A LARGE SURFACE HIGH OFFSHORE WILL MAINTAIN MODERATE TO 
STRONG LOW LEVEL ONSHORE FLOW OVER WESTERN WASHINGTON THROUGH MID 
NEXT WEEK. THIS WILL MAINTAIN THE PATTERN OF MORNING CLOUDS WITH 
VARYING DEGREES OF PARTIAL AFTERNOON CLEARING. WEAK LOW PRESSURE 
ALOFT WILL BRING A CHANCE OF SHOWERS...MAINLY OVER THE MOUNTAINS 
AFTERNOON AND EVENINGS.

&&

.SHORT TERM...THE LARGE NE PACIFIC SURFACE HIGH WILL BE DOING ITS 
DOMINANT THING FOR THE NEXT WEEK...MAINTAINING MODERATE TO STRONG 
ONSHORE FLOW ACROSS W WA. THE ONSHORE FLOW DIRECTION WILL BE 
PREDOMINANTLY SW SO LOW LEVEL MARINE MOISTURE WILL HAVE AN EASIER 
TIME SPREADING INLAND UP THROUGH PUGET SOUND. SKIES WILL REMAIN 
MOSTLY CLOUDY WHICH WILL KEEP TEMPERATURES CLOSE TO NORMAL MAY 
RANGES. THERE WILL PROBABLY BE VARYING DEGREES OF PARTIAL CLEARING 
FROM DAY-TO-DAY BUT OVERALL SKIES WILL REMAIN MOSTLY CLOUDY. THE 
MARINE LAYER IS DEEP ENOUGH AND WITH A WEAK UPPER LEVEL TROUGH OVER 
THE OFFSHORE WATERS IT SEEMS REASONABLE TO HANG ON TO THE CHANCE OF 
DRIZZLE FOR THE WEST PART.

THE MAIN ISSUE THIS AFTERNOON HAS BEEN THE SHOWERS AND ISOLATED 
THUNDERSTORMS OVER THE CASCADES HEADED VERY SLOWLY IN THE DIRECTION 
OF THE LOWLANDS...AND SHOWERS OVER THE OLYMPICS MOVING N AND 
CROSSING THE STRAIT OF JUAN DE FUCA ZONES. THERE IS STILL TIME FOR 
THE SHOWERS TO WEAKEN AND DISSIPATE BEFORE REACHING THE 
LOWLANDS...BUT I WILL BE CONSERVATIVE AND EXPAND THE CHANCE OF 
SHOWERS OVER MORE OF THE LOWLANDS THIS EVENING. 

THE WEAK UPPER LEVEL TROUGH JUST OFFSHORE WILL SHIFT OVER W WA ON 
SATURDAY. THIS WILL SHIFT THE MID LEVEL FLOW OVER W WA FROM E-SE TO 
SW OVER THE COAST AND S OVER THE INTERIOR. THE MAIN EFFECT SHOULD BE 
TO RESTRICT CONVECTION TO THE CASCADES RATHER THAN HAVE CELLS 
DRIFTING W OVER THE LOWLANDS. AN UPPER LEVEL LOW ALONG THE B.C. 
COAST TODAY WILL DROP DOWN OVER SW B.C. SUNDAY AFTERNOON...SHIFTING 
THE MID LEVEL FLOW TO W OVER W WA. THIS SHOULD END THE THREAT OF 
THUNDERSTORMS FOR THE CASCADES...ALTHOUGH THERE COULD STILL BE SOME 
SHOWERS RIGHT ALONG THE CREST. 

THE 12Z ECMWF TAKES THE LOW SE OVER E WA MONDAY AFTERNOON WHILE THE 
18Z GFS DROPS IT DOWN OVER W WA. THE 12Z GFS WAS SIMILAR TO THE 
ECMWF SO IT APPEARS THERE COULD BE SOME UNCERTAINTY OVER THE NEXT 
COUPLE OF DAYS REGARDING WHERE THE LOW GOES. THE ECMWF TRACK SHOULD 
KEEP MOST SHOWERS OVER THE CASCADES AND MOST OF THE LOWLANDS 
DRY...WHILE THE GFS WOULD SPREAD SHOWERS ACROSS MORE OF THE 
LOWLANDS. THE FORECAST FOLLOWS THE 12Z GFS AND ECMWF. GFS MID-LEVEL 
LAPSE RATES SUGGEST THE AIR MASS WILL BE TOO STABLE FOR 
THUNDERSTORMS. KAM

.LONG TERM...GFS/ECMWF TAKE THE UPPER LEVEL LOW E ON TUESDAY WITH N 
FLOW ALOFT DEVELOPING OVER W WA. THIS SHOULD END ANY THREAT OF 
SHOWERS FOR THE LOWLANDS AND PROBABLY THE CASCADES AS WELL. THE 
SURFACE RIDGE OVER THE NE PACIFIC WILL MAINTAIN THE ONSHORE FLOW 
PATTERN NEXT WEEK FOR MOSTLY CLOUDY SKIES...BUT THE FLOW COULD 
WEAKEN ENOUGH FOR A BIT MORE AFTERNOON SUNSHINE. KAM

&&

.AVIATION...NO MAJOR CHANGES TO THE BLOCKED UPPER LEVEL PATTERN
ARE EXPECTED OVER THE PAC NW THRU THIS WEEKEND. THE FLOW ALOFT
WILL GENERALLY BE LIGHT AND VARIABLE. THE TSTMS OVER THE CASCADES
WILL DISSIPATE AFTER 0300 UTC. 

MEANWHILE...CIGS MAINLY IN THE 1-2K FT RANGE BLANKETED MUCH OF THE
LOWLANDS THIS AFTERNOON. THE MARINE LAYER WAS QUITE DEEP /TOPS
WERE RUNNING 5500 TO 6 FT/...SO NOT EXPECTING MUCH /IF ANY/ 
IMPROVEMENT THE REST OF TODAY. MVFR CIGS WILL PERSIST THRU 
TONIGHT...ALTHOUGH THERE WILL BE AREAS OF IFR CIGS /500-1K FT/
AND VSBYS 3-5SM MAINLY OVER THE COAST. THE OLYMPICS AND CASCADES 
WILL BE PARTIALLY OBSCD.

KSEA...CIGS SHOULD BE IN THE 2-3K RANGE THE REST OF TODAY...AND
WILL LOWER INTO THE 1-2K FT RANGE OVERNIGHT. MVFR CONDITIONS WILL
PERSIST THRU SATURDAY MORNING.

&&

.MARINE...
NO SIGNIFICANT CHANCES ARE ANTICIPATED IN THE WEATHER PATTERN
THROUGH THE MIDDLE OF NEXT WEEK. HIGH PRES WILL REMAIN OFFSHORE.
THIS COMBINED WITH LOWER PRES INLAND WILL RESULT IN CONTINUED
ONSHORE FLOW OF VARYING STRENGTH THROUGH NEXT WED.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY IS IN EFFECT FOR THE CENTRAL AND EASTERN
     STRAIT OF JUAN DE FUCA.

&&

$$













[ W WA | SW WA and W OR | SE WA and NE OR | NE WA and N ID ]

Southwestern Washington and Western Oregon


056 
FXUS66 KPQR 222126
AFDPQR

AREA FORECAST DISCUSSION 
NATIONAL WEATHER SERVICE PORTLAND 
225 PM PDT FRI MAY 22 2015

.SYNOPSIS...AN UPPER LOW OFF THE NORTH OREGON COAST THIS EVENING
DIVES SOUTH TONIGHT AND SATURDAY...WHILE ANOTHER UPPER LOW SETTLES
OVER VANCOUVER ISLAND. THE MARINE LAYER WILL DEEPEN TONIGHT AND
SATURDAY. THE ONSHORE FLOW WEAKENS A LITTLE SUNDAY. THE UPPER LOW
MOVES OVER CENTRAL WASHINGTON MEMORIAL DAY THEN SHIFTS EAST TUESDAY.
A GRADUAL WARMING TREND IS EXPECTED MID TO LATE NEXT WEEK. 

&&

.SHORT TERM...TONIGHT THROUGH MEMORIAL DAY...COMPLEX LARGE-SCALE
PATTERN WILL CONTINUE OVER THE PACIFIC NORTHWEST THROUGH THE SHORT
TERM. AT 20Z WATER VAPOR LOOP SHOWED A LARGE LOW PRESSURE AREA
EXTENDING FROM SOUTHERN OREGON TO SOUTHERN CALIFORNIA. ANOTHER UPPER
LOW WAS CENTERED OVER THE CENTRAL BRITISH COLUMBIA COAST...AND A
THIRD BUT MORE SUBTLE LOW CIRCULATION WAS NOTED OFF THE S WASHINGTON
COAST. THE FORECAST AREA LIES IN A BROAD DEFORMATION AREA...WITH EAST
FLOW ALOFT OVER THE FAR SOUTH AND S-SW FLOW ALOFT IN THE FAR NORTH.
BULK OF THE MOISTURE AND LIFT WAS OVER ERN OREGON. KRTX DUAL-POL
DOPPLER RADAR CONTINUES TO SHOW SCATTERED PRECIP ACTIVITY. BETWEEN
19Z AND 20Z SEVERAL LIGHTNING STRIKES WERE NOTED NEAR BENNETT PASS.  

NOT ANTICIPATING ANY THUNDERSTORMS LATE THIS AFTERNOON THROUGH THE
EVENING AS A GRADUAL SWITCH TO NWLY MID-LEVEL FLOW DEVELOPS. NOT
EXPECTING MUCH IN THE WAY OF LATE-AFTERNOON OR EARLY-EVENING CLEARING
TODAY...AS DEPICTED IN THE HI-RES WRF-ARW MODEL. AT 21Z THE KTTD-KDLS
GRADIENT WAS 4.7 MB...AND THE MORE SYNOPTIC KOTH-KGEG GRADIENT WAS
11.7 MB. THESE VALUES SUGGEST SUBSTANTIAL ONSHORE LOW-LEVEL
FLOW...WHICH IS READILY APPARENT IN VISIBLE IMAGERY. 

THE SMALL UPPER LEVEL CIRCULATION SEEN IN WATER VAPOR OFF THE S WA
COAST THIS MORNING GRADUALLY SINKS SOUTH TONIGHT. GFS PICKS UP ON
THIS FEATURE AND DEVELOPS A CLOSED LOW OVER NRN CAL BY SAT AFTERNOON.
MEANWHILE...ANOTHER UPPER LOW ALONG THE BRITISH COLUMBIA COAST SLOWLY
DRIFTS SOUTH SAT. HOWEVER...THE MAIN WEATHER DRIVER FOR THE AREA
TONIGHT AND SAT WILL BE IN THE LOWER LEVELS. SURFACE HIGH PRES
STRENGTHENS OVER THE NE PAC TONIGHT AND SAT...INDUCING STRONGER
ONSHORE FLOW. MODEL SOUNDINGS FOR THE WILLAMETTE VALLEY VALID 12Z SAT
YIELD CLOUD TOPS TO NEARLY 5000 FT MSL. AM A LITTLE MORE CONFIDENT
THERE WILL BE DRIZZLE ALONG THE COAST AND WEST SLOPES OF THE COAST
RANGE AND INTO THE WILLAPA HILLS OF SW WA LATE TONIGHT AND SAT
MORNING. NAM TIME-HEIGHT SECTION FOR KPDX SHOWS 90 PCT OR GREATER RH
UP TO AROUND 850 MB SAT AFTERNOON. HAVE INCREASED SKY COVER IN THE
GRIDS...ESPECIALLY TONIGHT AND SAT.  

MODEL SOUNDINGS AND TIME-HEIGHT SECTIONS VALID SUN INDICATE LOWER
CLOUD TOPS AND A LITTLE WEAKER ONSHORE GRADIENTS. THUS...SHOULD SEE
MORE AFTERNOON CLEARING...ESPECIALLY IN THE SOUTH PART OF THE
FORECAST AREA. GFS AND ECMWF IN GENERAL AGREEMENT MON WITH THE UPPER
LOW NEAR THE SOUTH END OF VANCOUVER ISLAND AT 12Z...THEN OVER NRN WA
BY 00Z TUE. ECMWF CONTINUES TO BE A LITTLE MORE E WITH IT COMPARED TO
THE GFS. CYCLONIC 500 MB FLOW IN CONJUNCTION WITH STRONGER ONSHORE
LOW-LEVEL FLOW WILL RESULT IN A DEEPER MARINE LAYER MEMORIAL DAY
MORNING. THE NAM TIME-HEIGHT SECTION FOR KPDX BEARS THIS OUT. HAVE
ADDED A MENTION OF DRIZZLE SUN NIGHT AND MON MORNING TO ACCOUNT FOR
THIS. WEISHAAR

.LONG TERM...MONDAY NIGHT THROUGH FRIDAY...BY MONDAY NIGHT AN UPPER 
LEVEL LOW PRESSURE SYSTEM WILL BE SLIDING GENERALLY THROUGH THE 
REGION...THOUGH CONFIDENCE IN THE PRECISE TIMING AND TRACK REMAIN 
RELATIVELY LOW. MODELS SEEM TO BE CLUSTERING ON A SOLUTION THAT 
DROPS THE LOW ALONG OR EAST OF THE CASCADES AS IT MOVES SOUTH FROM 
CANADA...WHICH WILL PROVIDE FOR PLENTY OF MARINE CLOUDS BUT KEEP 
MOST PRECIPITATION IN THE HIGHER TERRAIN OF THE CASCADES. 
THEN...SHORTWAVE RIDGING WILL LIKELY BEGIN TO BUILD OVER THE REGION 
FOR DRY CONDITIONS AND WARMING...PARTICULARLY FOR THE SECOND HALF OF 
THE WEEK. WHILE MODEL SPREAD REMAINS SOMEWHAT LARGE WITH RESPECT TO 
HOW HIGH HEIGHTS WILL RISE...HIGH TEMPERATURES COULD CLIMB INTO THE 
LOWER 80S FOR THE INTERIOR ON FRIDAY.  CULLEN
&&

.AVIATION...CONDITIONS ACROSS THE REGION CONTINUE TO REMAIN
MVFR...WITH SOME HIGH-END IFR CIGS ALONG THE COAST. VISIBLE
SATELLITE IMAGERY IS SHOWING HINTS OF SOME CLOUD BREAKS OVER THE
INTERIOR. HOWEVER...IT IS NOT ENOUGH TO SAY WITH ANY CONFIDENCE
THAT VFR CIGS WILL DEVELOP TODAY. SCATTERED SHOWERS CONTINUE TO
DRIFT SOUTH ACROSS THE INTERIOR. AS SUCH...EXPECT MVFR CIGS TO
CONTINUE IN THE INTERIOR. ANY VFR CIGS THAT DO DEVELOP THIS
AFTERNOON/EVENING WILL LIKELY BE SHORT LIVED. MVFR CIGS ALONG THE
COAST WILL LOWER TOWARDS A MIXTURE OF MVFR/IFR CIGS LATE TONIGHT.
AREAS OF DRIZZLE POSSIBLE LATE TONIGHT THROUGH SAT MORNING.

KPDX AND APPROACHES...MVFR CIGS WILL CONTINUE THROUGH SAT. THERE
IS A 30 PERCENT CHANCE THAT CIGS COULD BECOME VFR FOR A FEW HOURS
THIS AFTERNOON/EVENING. PERIODS OF DRIZZLE LIKELY TO IMPACT THE
TERMINAL LATE TONIGHT THROUGH SAT MORNING.

&&

.MARINE...A PERSISTENT WEATHER PATTERN WILL CONTINUE TO BRING
BENIGN CONDITIONS TO THE WATERS THROUGH EARLY NEXT WEEK. NW WINDS
ARE EXPECTED TO GENERALLY REMAIN BELOW ADVISORY LEVEL WITH HIGH
PRES WELL OFFSHORE. A FRESH SWELL OF 5 TO 6 FT WILL ALSO CONTINUE
OUT OF THE WNW.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...NONE.

&&

$$

INTERACT WITH US VIA SOCIAL MEDIA     
WWW.FACEBOOK.COM/NWSPORTLAND	
WWW.TWITTER.COM/NWSPORTLAND

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


474 
FXUS66 KPDT 222253 AAA
AFDPDT

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PENDLETON OR
400 PM PDT FRI MAY 22 2015

UPDATED AVIATION DISCUSSION

.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...LOW PRESSURE TO THE 
SOUTH WAS PUSHING ABUNDANT MOISTURE NORTH AND INTO THE TWO STATE 
AREA THIS AFTERNOON THAT WILL PERSIST INTO THIS EVENING WITH SHOWERS 
AND THUNDERSTORMS EXPECTED. PWATS WERE AROUND AN INCH AND SOME 
THUNDERSTORMS WILL CONTINUE PRODUCING HEAVY RAIN ESPECIALLY IN THE 
FLASH FLOOD WATCH AREAS THAT INCLUDE ALONG THE EAST SLOPES OF THE 
WASHINGTON CASCADES AND OVER THE BLUE/WALLOWA/JOHN DAY HIGHLANDS. IN 
ADDITION HAIL WILL BE POSSIBLE WITH THE STRONGEST STORMS. THE STORMS 
WILL DECREASE AFTER SUNSET AND THE BULK OF THE PCPN SHOULD BE OVER 
THE CENTRAL PORTIONS OF THE AREA TOWARD MORNING. ANOTHER ROUND OF 
SHOWERS/TSRA ARE EXPECTED TO DEVELOP AND EXPAND IN COVERAGE SATURDAY 
AFTERNOON AND CONTINUE INTO SATURDAY NIGHT. AS THE LOW DRIFTS AWAY 
FROM THE REGION DRIER AIR WILL MOVE INTO THE TWO STATE AREA SUNDAY. 
HOWEVER A DISTURBANCE IS FORECAST TO MOVE ACROSS THE AREA SUNDAY 
AFTN THAT WILL COMBINE WITH DAYTIME HEATING TO PRODUCE SHOWERS AND 
ISOLD TSRA AGAIN OVER PORTIONS OF THE REGION INTO SUNDAY NIGHT. 

AFTERNOON TEMPS WILL BE NEAR NORMAL SATURDAY WITH A WARMING TREND 
EXPECTED INTO SUNDAY.

.LONG TERM...MEMORIAL DAY THROUGH FRIDAY.  MODELS ARE IN BETTER 
AGREEMENT BUT CONTINUE TO HAVE DISCREPANCIES ON THE PLACEMENT OF THE 
UPPER LOW MOVING SOUTH ACROSS WA/OR EARLY IN THE PERIOD.  IN 
GENERAL...THERE WILL BE A SLIGHT CHANCE TO A CHANCE OF SHOWERS AND 
THUNDERSTORMS ON MEMORIAL DAY THROUGH TUESDAY.  THIS COULD CONTINUE 
INTO WEDNESDAY DEPENDING IF THE GFS AND CANADIAN VERIFY WHICH KEEP 
THE LOW EAST OF THE CASCADES UNLIKE THE ECMWF WHICH PUSHES IT 
EASTWARD.  MODELS HAVE A HISTORY OF POOR PLACEMENT OF CLOSED LOWS 
AND TEND TO FORCE LOWS OUT OF THE REGION TOO FAST.  KEEPING THIS IN 
MIND...WILL FOLLOW THE SLOWER SOLUTIONS OF GFS/CANADIAN.  THE LONG 
DURATION OF THE BROAD UPPER LEVEL TROUGH AND CYCLONIC FLOW MAY 
FINALLY TRANSITION TO A DRIER RIDGE PATTERN BY THE END OF THE WORK 
WEEK.  WILL LOWER POPS AND KEEP ABOVE SEASONAL TEMPERATURES IN THE 
FORECAST BY FRIDAY.  WISTER

&&

.AVIATION...00Z TAFS. SHOWERS AND THUNDERSTORMS HAVE ONCE AGAIN 
DEVELOPED OVER THE FORECAST AREA.  ALL TERMINAL AIRPORTS HAVE A 
POTENTIAL TO OBSERVE A THUNDERSTORM OVER THE NEXT SEVERAL HOURS. 
MVFR CONDITIONS ARE POSSIBLE WHERE THUNDERSTORMS DEVELOP...AND KRDM 
AND KBDN HAVE SCUD CLOUDS DOWN TO 1500 FEET.  HEAVY RAIN WITH 
RAINFALL RATES OF 0.5 TO 1.0 PER HOUR ARE POSSIBLE.  CONDITIONS WILL 
IMPROVE SATURDAY MORNING...AND VFR CONDITIONS ARE FORECAST DURING 
THE DAY SATURDAY WITH ONLY ISOLATED SHOWERS AND THUNDERSTORMS 
EXPECTED. WESTERLY WINDS WILL CONTINUE AT 15 TO 25 KT AT THE KDLS.  
WISTER


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  54  75  51  73 /  60  40  20  10 
ALW  56  77  55  77 /  60  40  20  10 
PSC  58  82  54  82 /  50  40  10  10 
YKM  59  81  55  81 /  40  40  10  10 
HRI  57  80  53  78 /  50  40  10  10 
ELN  56  80  54  80 /  30  40  20  10 
RDM  44  70  39  72 /  20  20  10  10 
LGD  54  70  50  70 /  70  40  30  30 
GCD  49  71  45  72 /  70  30  20  10 
DLS  57  70  54  79 /  20  20  10  10 

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...FLASH FLOOD WATCH UNTIL 9 PM PDT THIS EVENING FOR ORZ049-050-502-
     503-505-506.

WA...FLASH FLOOD WATCH UNTIL 9 PM PDT THIS EVENING FOR WAZ030-520.

&&

FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON

$$

97/85/85

[ W WA | SW WA and W OR | SE WA and NE OR | NE WA and N ID ]

Northeastern Washington and Northern Idaho


674 
FXUS66 KOTX 222333
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
433 PM PDT FRI MAY 22 2015

.SYNOPSIS...
The Memorial Day Weekend is expected to be warmer than average,
with afternoon temperatures in the 70s and 80s. Look for scattered
showers and thunderstorms this weekend into next week. Some
thunderstorms will be capable of producing heavy downpours and
frequent lightning.

&&

.DISCUSSION...

Tonight: We'll be dealing with short-segment lines of
thunderstorms moving west off the higher terrain of N Idaho and
into Spokane and the Palouse. The other area of concern is the
potential for flash flooding/debris flows on recent 2013-2014
burn scars. So far most of these scars have been missed by the
heaviest rain rates in the Cascades. The Devels Elbow complex
south of Republic has, so far, received the most direct hit...but
calls to local authorities have yielded no reports of debris
flows. The CAPE/shear combo supports heavy downpours and small
hail into this evening with any thunderstorms. We'll be doing
NOWCASTS, Facebook posts and Twitter updates when time allows.bz

Saturday through Monday: Models are in pretty good agreement of
where to track the upper level low that is moving down British
Columbia and into the Inland Northwest this weekend. The low now
doesn't push into Washington until Sunday evening/Monday morning.
Until then...northeasterly flow into the northern Idaho Panhandle
and northeast Washington will keep conditions dry with mostly
clear skies. The main concern for showers and thunderstorms will
continue to remain across extreme southeast WA, the central ID
Panhandle and along the Cascades. Each afternoon and evening
showers and thunderstorms will develop and then wane with the
setting sun in the evening. Isolated showers is possible through
the overnight and early morning hours for the aforementioned
areas. Given we are expecting less shower activity and clouds
Saturday and early Sunday, have increased max temps about 1-3
degrees. Sunday night/Monday the upper low will move into
Washington. There are some model differences of where the low goes
during the day on Monday. Nevertheless the chance of widespread
rain will increase. Monday looks to be the 'crummiest' day of the
holiday weekend. Have lowered max temps a few degrees, as we
looked to be the outlier compared to other forecast models.
/Nisbet

´╗┐Monday night through Friday: The Inland NW remains unsettled
with some threat of showers and thunderstorms each day. Most
models keep the region in a weak flow pattern with a mid-level low
bobbling about the northwest United States at least through
Wednesday. Thereafter models diverge, either holding the low near
the northern Rockies or showing a transition to a west-southwest
flow with a low migrating down the BC coast. Either way
instability blossoms each afternoon, in the form of expanding
CAPE. Precisely how much synoptic forcing there is and where it
will lay will come into more focus as models come into better
agreement. But for now look for a threat of showers and
thunderstorms expanding each afternoon, then dissipating but not
entirely ending for the night and morning hours. The threat will
be best throughout the region through Wednesday. Thereafter there
is some suggestion that the threat will retreat away from deeper
Columbia Basin toward Thursday and Friday. Any of these
showers/t-storms may contain the typical brief heavy rain and
perhaps some small hail and lightning, but given the more
convective nature of the system none of this is a definite for any
one location. /J. Cote'


&&

.AVIATION...
00Z TAFS: Marjority of thunderstorms on the radar this evening are
moving with a general storm track to the southwest at around 20
mph. With loss of peak heating and limited dynamics to support
forced convection the aviation forecasts show majority of
thunderstorm activity gone from most TAF sites after 2Z and from
just about everywhere at 9Z Saturday. MVFR ceilings primarily from
the rain shafts and the small hail from some of the storms. Wind
shifts common through this evening due to all the outflow
boundaries propagating out of all the thunderstorms. TAFS have no
mention of shower or thunderstorm activity Saturday afternoon as
considerably lesser convective activity is expected. /Pelatti

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        53  82  52  80  53  73 /  10  10  10  20  30  50 
Coeur d'Alene  52  80  53  80  52  71 /  20  10  10  20  30  50 
Pullman        49  76  46  75  48  71 /  20  10  10  10  20  30 
Lewiston       56  82  55  82  55  79 /  30  20  20  20  20  30 
Colville       53  86  54  81  51  73 /  20  10  10  30  30  70 
Sandpoint      50  81  48  79  49  71 /  10  10  10  20  20  60 
Kellogg        50  80  49  80  48  70 /  20  20  10  20  20  50 
Moses Lake     56  86  55  83  54  80 /  20  10  10  10  20  20 
Wenatchee      59  85  59  81  57  79 /  50  10  10  20  20  10 
Omak           53  87  53  83  52  77 /  30  10  10  30  20  40 

&&

.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Flash Flood Watch until 8 PM PDT this evening for East Slopes 
     Northern Cascades.

&&

$$

[ W WA | SW WA and W OR | SE WA and NE OR | NE WA and N ID ]

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