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

Western Washington


178 
FXUS66 KSEW 010334
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
834 PM PDT SUN AUG 31 2014

.SYNOPSIS...A WEAK UPPER LEVEL TROUGH CROSSING THE AREA WILL 
MAINTAIN A CHANCE OF SHOWERS OVER THE CASCADES TONIGHT. THE 
ASSOCIATED WEAK FRONT WILL BRING A CHANCE OF SHOWERS TO THE NORTH 
COAST AND NORTH CASCADES LATE TONIGHT AND MONDAY. MOSTLY CLOUDY 
SKIES WILL CONTINUE OVER THE REST OF WESTERN WASHINGTON. RAIN IS 
LIKELY ON TUESDAY AS A VIGOROUS UPPER LEVEL TROUGH CROSSES THE 
REGION. AN UPPER LEVEL RIDGE OFFSHORE WILL BRING A GRADUAL WARMING 
AND DRYING PATTERN FROM WEDNESDAY THROUGH NEXT WEEKEND.

&&

.SHORT TERM...WATER VAPOR IMAGERY SHOWS A WEAK UPPER LEVEL SHORTWAVE 
TROUGH ALONG THE B.C. COAST THAT WILL BRUSH PAST THE NORTH PART OF W 
WA TONIGHT. THE WILL BRING A CHANCE OF SHOWERS TO THE CASCADES...BUT 
MAINLY THE NORTH PART. IR AND VISIBLE SATELLITE IMAGERY SHOW A LOT 
OF MID LEVEL CLOUDS JUST OFFSHORE THAT SHOULD SPREAD OVER W WA 
OVERNIGHT...ALTHOUGH THE OLYMPICS MAY SHIELD THE PUGET SOUND REGION 
A BIT. THE VERY WEAK SURFACE FRONT PRESENTLY ASSOCIATED WITH THE 
UPPER TROUGH WILL GLIDE TO THE COAST LATE TONIGHT THEN FALL APART 
MONDAY. A LITTLE LIGHT RAIN IS POSSIBLE FOR THE N COAST AND N 
INTERIOR MONDAY AS THE FRONT DISSIPATES. THE PUGET SOUND REGION AND 
SW INTERIOR WILL PROBABLY BE THE LEAST AFFECTED BY THE DISSIPATING 
FRONT AND SO COULD SEE SOME PARTIAL SUNSHINE MONDAY AFTERNOON. 

MODELS HAVE BEEN REASONABLY CONSISTENT WITH THE TIMING AND TRACK OF 
THE VIGOROUS UPPER LEVEL TROUGH THAT IS EXPECTED TO CROSS THE AREA 
ON TUESDAY. THIS TROUGH SHOWS UP NICELY ON WATER VAPOR IMAGERY OVER 
THE GULF OF AK THIS EVENING...AND WILL MOVE SE ALONG THE B.C. COAST 
THROUGH MONDAY NIGHT...ENDING UP OVER W WA ON TUESDAY. LATEST MODEL 
TIMING HAS THE BEST CHANCE OF RAIN TUESDAY AFTERNOON. THE NAM IS THE 
DRIEST MODEL WITH ONLY A FEW HUNDREDTHS OF AN INCH OF RAIN...WHILE 
THE ECMWF IS WETTEST WITH 2 TO 4 TENTHS OVER THE NORTH. THIS IS A 
FAIRLY DRY TRACK FOR THE TROUGH AND IT IS FAST MOVING...SO ACTUAL 
RAINFALL ACCUMULATIONS WILL PROBABLY FALL IN-BETWEEN THE TWO MODELS. 
THE TROUGH WILL DRAG MUCH COOLER AIR ALOFT OVER THE AREA TUESDAY 
NIGHT WITH SNOW LEVELS OVER THE CASCADES DROPPING DOWN TO JUST ABOVE 
6000 FEET AFTER MIDNIGHT. THERE COULD STILL BE SOME LIGHT SHOWERS 
AROUND FOR A TINY BIT OF MOUNTAIN S.N.O.W. 

THE UPPER LEVEL TROUGH WILL MOVE QUICKLY EAST TUESDAY 
NIGHT...ALLOWING DRIER N FLOW ALOFT FROM AN OFFSHORE UPPER LEVEL 
RIDGE TO MOVE OVER THE AREA. WELL DEVELOPED SW ONSHORE FLOW TUESDAY 
NIGHT WILL KEEP THE LOWER AIR MASS MOIST WITH STRATUS THROUGH 
WEDNESDAY MORNING. WITH DRY AIR ALOFT THE STRATUS SHOULD CLEAR OUT 
BY AFTERNOON. WEDNESDAY SHOULD BE SLIGHTLY WARMER THAN TUESDAY...BUT 
THE RESIDUAL COOL AIR MASS FROM THE UPPER TROUGH WILL CAP MAX TEMPS 
IN THE 60S TO NEAR 70. KAM

.LONG TERM...PREVIOUS DISCUSSION FROM THE 334 PM AFD...MEDIUM RANGE 
MODELS ALL AGREE ON THE ZONAL FLOW OVER THE NORTHEAST PACIFIC 
BUCKLING INTO A HIGHER AMPLITUDE PATTERN BY MIDWEEK. THIS PATTERN 
WILL BE ANCHORED BY A LARGE SCALE RIDGE THAT WILL BUILD ALONG 140W 
TUESDAY AND INTO BRITISH COLUMBIA BY WEDNESDAY NIGHT. MODELS DO 
DISAGREE ON THE FLOW DOWNSTREAM OF THE RIDGE ON FRIDAY WITH VARYING 
DEGREES OF SPLIT FLOW ALOFT OVER THE NORTHWEST AND A WEAK UPPER 
LEVEL LOW OVER THE GREAT BASIN OR CENTRAL ROCKY MOUNTAINS. 
NONETHELESS THE LARGE SCALE PATTERN WILL KEEP THE PACIFIC NORTHWEST 
DRIER AND WARMER BEGINNING WEDNESDAY AFTERNOON AND PERSISTING 
THROUGH THE WEEKEND. MODELS GENERALLY AGREE ON A SYSTEM RIDING OVER 
THE TOP RIDGE AND INTO THE NORTHWEST LATE SUNDAY INTO MONDAY 
MORNING.  

&&

.AVIATION...LIGHT NW FLOW ALOFT OVER THE REGION THROUGH MONDAY. 
LIGHT LOW LEVEL ONSHORE FLOW. A WEAK TROUGH WILL DISSIPATE AS IT 
REACHES THE COAST MONDAY MORNING. THE AIR MASS IS GENERALLY MOIST 
AND STABLE...EXCEPT WEAKLY UNSTABLE MONDAY AFTERNOON. ONLY A SLIGHT 
CHANCE OF A FEW SHOWERS...MAINLY N OF SEATTLE ON MONDAY AFTERNOON. 
AN MVFR CEILING IS EXPECTED TO FORM OVER SOME PARTS OF THE AREA LATE 
TONIGHT AND MONDAY MORNING...LIFTING AND SCATTERING BY 18Z. 
 
KSEA...LIGHT WIND...BECOMING S-SW TO 5 KNOTS LATE TONIGHT AND 
MONDAY. MVFR CIGS ARE LIKELY TO FORM AFTER MIDNIGHT...THEN LIFT AND 
SCATTER BY 18Z. DTM

&&

.MARINE...A WEAK SYSTEM WILL DISSIPATE AS IT REACHES THE COAST 
MONDAY MORNING...GIVING A SLY BREEZE OVER THE COASTAL WATERS. 
ANOTHER SYSTEM WILL BRING A BOUT OF STRONG ONSHORE FLOW TUESDAY 
NIGHT...THEN EASING ON WEDNESDAY. THE REST OF THE WEEK WILL BE A 
MORE SUMMERY WIND REGIME WITH A TYPICAL NW BREEZE EACH DAY. DTM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY CENTRAL AND EASTERN STRAIT OF JUAN DE FUCA 
     THROUGH 1 AM PDT MONDAY.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT 
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


251 
FXUS66 KPQR 010433
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
931 PM PDT SUN AUG 31 2014

.SYNOPSIS...CLOUDS ARE CLEARING ACROSS MUCH OF THE REGION THIS
EVENING...BUT THEY ARE EXPECTED TO REFORM ALONG THE COAST OVER THE
NEXT FEW HOURS AND THEN PUSH PARTIALLY INLAND OVERNIGHT. WEAK UPPER
RIDGING SHOULD BRING WARMER AND DRY CONDITIONS FOR MON...BUT ANOTHER
FRONT WILL PUSH ACROSS THE REGION LATER TUE...BRINGING ANOTHER CHANCE
OF SHOWERS. THEN WARMER AND DRY WEATHER IS FORECAST FOR REST OF THE
WEEK UNDER OFFSHORE FLOW. 
&&

.SHORT TERM...TONIGHT THROUGH WEDNESDAY.
THE LATEST OBSERVATIONS AND SATELLITE IMAGERY SHOW CLOUDS SCATTERING
ACROSS THE REGION THIS EVENING. THERE WERE A FEW SPRINKLES AROUND THE
REGION TODAY...BUT THE ATMOSPHERE IS STABILIZING NOW AND DOPPLER
RADAR IS SHOWING NOTHING OVER THE PAST HOUR OR TWO. SO DECIDED TO
REMOVE ANY MENTION OF SHOWERS FROM THE FCST FOR THE REST OF THE
NIGHT. MARINE CLOUDS SHOULD REFORM ALONG THE COAST OVER THE NEXT FEW
HOURS...THEN PUSH PARTIALLY INLAND OVERNIGHT. 500 MB HEIGHTS ARE
BEGINNING TO RISE AND THE ONSHORE FLOW IS NOT VERY STRONG...SO DO NOT
EXPECT A VERY IMPRESSIVE INLAND PUSH. STRATUS WILL PROBABLY STRUGGLE
TO MAKE IT MUCH BEYOND KELSO. ANOTHER CLOUD DECK MAY FORM ALONG THE
CASCADE FOOTHILLS AND BACK BUILD TOWARD THE WILLAMETTE VALLEY. 
	
THE NW FLOW REMAINS OVER PAC N TO START THE UPCOMING WEEK...WITH
ONSHORE FLOW KEEPING A MIX OF SUN AND CLOUDS CONTINUING ACROSS THE
REGION. THE STORM TRACK WILL KEEP THE EMBEDDED DISTURBANCES TO THE N
ACROSS BRITISH COLUMBIA AND WASHINGTON. TOMORROW LOOKS DRY AS THREAT
OF SHOWERS ASSOCIATED WITH A DISSIPATING FRONT LOOKS TO REMAIN TO THE
NORTH OF OUR FORECAST AREA. TEMPERATURES SHOULD INCREASE A BIT BACK
TOWARD SEASONAL NORMALS IN RESPONSE TO THE INCREASING 500 MB HEIGHTS.


THE NEXT FRONT WILL ARRIVE LATER TUE...BRINGING INCREASING CLOUDS 
AND A DECENT CHANCE OF SHOWERS OR BRIEF LIGHT RAIN TO THE REGION. 
WILL KEEP WITH CHANCE OF SHOWERS N OF A TILLAMOOK TO MT HOOD LINE AND
KEEP IT DRY TO THE S. LIKE MON...BULK OF PRECIP REMAINS ACROSS
WESTERN WASHINGTON AND BRITISH COLUMBIA.	 

THEN WILL CHANGE OVERALL WEATHER PATTERN...AS HIGH PRES BEGINS TO
BUILD ACROSS THE REGION. DRY AND MILD FOR WED...AFTER SOME MORNING
CLOUDS. PYLE/ROCKEY

.LONG TERM...AN UPPER LEVEL RIDGE NOSES INTO WESTERN CANADA AND 
NORTHERN WASHINGTON THURSDAY...BUT A LOW OFF OF CALIFORNIA WILL 
MAINTAIN LOWER PRESSURE OVER NW OREGON. HIGH PRESSURE TO THE NORTH 
AND EAST...WITH LOW PRESSURE TO THE SOUTH AND SOUTHEAST WILL RESULT 
IN OFFSHORE WINDS ACROSS THE PORTLAND FORECAST AREA. EXPECT AN 
INCREASE IN SUNSHINE AND AFTERNOON TEMPERATURES THURSDAY THROUGH 
NEXT SATURDAY. BEYOND THAT...THE MODELS ARE STARTING TO HINT AT 
ANOTHER SYSTEM PUSHING INTO THE PACIFIC NORTHWEST LATE NEXT SUNDAY. 
WITH THIS SYSTEM WE WILL LIKELY SEE A SLIGHT DECREASE IN AFTERNOON 
TEMPERATURES. A SLIGHT CHANCE OF SHOWERS ARE ALSO NOT OUT OF THE 
QUESTION. TJ/64
&&

.AVIATION...IFR CONDITIONS EXPECTED TO RE-DEVELOP ALONG THE COAST
TONIGHT AFTER 02Z-04Z. SOME SCATTERED LOW CLOUDS EXPECTED INLAND
MON MORNING MAINLY AFTER 12Z...BUT INLAND SITES SHOULD REMAIN VFR
MON AND EVEN COASTAL SITES LOOK LIKE THEY WILL CLEAR OUT BY MONDAY
AFTERNOON.

KPDX AND APPROACHES...VFR CONDITIONS TONIGHT AND MON. A 10 PERCENT
CHANCE OF SOME BRIEF MVFR CIGS 13Z-17Z MON MORNING. BOWEN/TW

&&

.MARINE...A WEAK FRONT WILL BRUSH THE AREA ON MONDAY...THEN HIGH
PRESSURE RETURNS TO THE NORTHEAST PACIFIC TUESDAY WITH THERMAL
LOW PRESSURE STRENGTHENING OVER INTERIOR NORTHERN CALIFORNIA. THIS
WILL PLACE THE WATERS IN A FAMILIAR PATTERN THAT HAS OCCURRED
SEVERAL TIMES THIS SUMMER WITH PERIODS OF GUSTY NORTHERLY
WINDS....ESPECIALLY IN THE AFTERNOON AND EVENING HOURS. LATEST MODELS
INCREASE WINDS SLIGHTLY FURTHER THURSDAY AND FRIDAY WITH THURSDAY
NIGHT BEING THE MAIN FOCUS SO FOLLOWED THIS TREND WITH EVENING
FORECAST UPDATE. ALSO UPPED WIND WAVES AND THUS COMBINED SEAS FOR
THE SAME TIME FRAME. EXPECT SEAS TO FLUCTUATE GENERALLY BETWEEN 4
AND 7 FT...PEAKING LATE THURSDAY AT 8 FT...WITH THE PREDOMINANT
SWELL REMAINING AROUND 9 TO 10 SECONDS OUT OF THE NORTHWEST.
BOWEN/TW

&&

.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


725 
FXUS66 KPDT 010509 AAA
AFDPDT

AREA FORECAST DISCUSSION...UPDATED AVIATION DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
1015 PM PDT SUN AUG 31 2014

.UPDATE...NORTHWEST FLOW CONTINUES ACROSS THE REGION TONIGHT WITH A 
FEW MID AND HIGHER LEVEL CLOUDS MOVING THROUGH...BUT OVERALL MOSTLY 
CLEAR SKIES. WINDS ARE STARTING TO DECREASE WITH THE FORECAST IN 
GOOD SHAPE. NO UPDATES. ML


&&

.PREV DISC... /ISSUED 220 PM PDT SUN AUG 31 2014/ 

SHORT TERM...TONIGHT THROUGH WEDNESDAY. SCATTERED CUMULUS OVER THE 
FORECAST AREA TODAY DUE TO COLDER AIRMASS ALOFT. EXPECT THIS TO 
DIMINISH AFTER SUNSET. MAINLY CLEAR OVERNIGHT WITH COOL 
TEMPERATURES. LOWS WILL BE IN THE 40S MOST LOCATIONS. DRY NORTHWEST 
FLOW CONTINUES MONDAY. HEIGHTS ARE BUILDING WITH SOME AIRMASS 
WARMING SO HIGHS SHOULD BE UP 3-7 DEGREES FROM TODAY UNDER MOSTLY 
SUNNY SKIES. ON TUESDAY AN UPPER LEVEL TROUGH WILL BE MOVING ACROSS 
SOUTHERN BC INTO THE PACIFIC NORTHWEST DURING THE DAY. THIS WILL 
BRING INCREASING WESTERLY WINDS IN THE AFTERNOON. OTHERWISE PARTLY 
TO MOSTLY SUNNY SKIES. THE UPPER TROUGH MOVES SLOWLY ACROSS THE 
FORECAST AREA TUESDAY NIGHT INTO WEDNESDAY. LOOKS TO BE A FAIRLY DRY 
SYSTEM WITH PARTLY CLOUDY AND COOLER CONDITIONS.  94

LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...AN UPPER LEVEL TROUGH 
WILL BE DEPARTING THE REGION LATE WEDNESDAY AND EARLY THURSDAY. THIS 
WILL ALLOW THE EASTERN PACIFIC RIDGE OF HIGH PRESSURE TO PUSH INTO 
THE REGION FOR THE REMAINDER OF THE LONG TERM PERIOD PROVIDING A 
WARMING AND DRY FORECAST INTO NEXT WEEKEND. 

AVIATION...06Z TAFS...VFR CONDITIONS WILL PREVAIL OVER THE NEXT 24 
HOURS UNDER MOSTLY CLEAR SKIES. WINDS WILL BE LESS THAN 10 KNOTS 
OVERNIGHT AND THEN INCREASE TO 10 TO 15 KTS MONDAY AFTERNOON.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  49  79  50  78 /  10   0   0   0 
ALW  53  79  55  78 /  10   0   0   0 
PSC  48  82  53  80 /  10   0   0   0 
YKM  45  79  51  76 /  10   0   0   0 
HRI  47  82  51  80 /  10   0   0   0 
ELN  49  78  52  72 /  10  10   0  10 
RDM  39  78  41  78 /   0   0   0   0 
LGD  46  76  45  77 /  10   0   0   0 
GCD  44  78  46  81 /  10   0   0   0 
DLS  53  81  55  76 /  10  10   0  10 

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&

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

$$

93/91/91




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

Northeastern Washington and Northern Idaho


121 
FXUS66 KOTX 010407
AFDOTX

Area Forecast Discussion
National Weather Service Spokane WA
907 PM PDT SUN AUG 31 2014

.SYNOPSIS...
Labor Day will bring dry conditions with temperatures slightly
below average. The arrival of a cold front Tuesday afternoon will
bring a return of breezy conditions and below average temperatures
for Wednesday, along with some threat of showers and
thunderstorms. A warming and drying trend is expected Thursday
into next weekend.

&&

.DISCUSSION...
Update: An upper level jet will gradually lift northeast of the
region by Monday morning which will put the Inland Northwest on
the warmer and more stable side of the jet. Still a few showers
remaining this evening around Bonners Ferry but with the jet
lifting north and drier air aloft moving in these should end by
Monday morning. Minor update made to sky cover and POP's based off
latest satellite and radar trends.  JW 

&&

.AVIATION...
06Z TAFS: A few light showers will linger tonight north of the
TAF sites around Bonners Ferry. There has been a concern for
stratus to redevelop tonight around KSFF/KCOE however dew points
are running around 6 degrees lower at Spokane and Coeur D'Alene
compared to this time yesterday. Also NAM model shows a drier
boundary layer tonight and thus a MVFR stratus deck does not
appear likely for any of the TAF sites. Up near the Canadian
border around Sandpoint and Bonners Ferry a bit more low level
moisture exists where a MVFR stratus deck is possible Monday
morning. JW

&&

.PRELIMINARY POINT TEMPS/POPS...
Spokane        50  74  51  75  50  68 /   0   0   0   0  20  20 
Coeur d'Alene  49  72  49  75  49  67 /  10  10   0   0  20  30 
Pullman        45  74  45  77  46  68 /   0   0   0   0  10  20 
Lewiston       54  79  54  84  55  73 /   0   0   0   0   0  10 
Colville       44  75  45  78  44  70 /  10  10   0  10  30  20 
Sandpoint      45  70  46  74  47  64 /  10  10   0   0  40  50 
Kellogg        47  68  49  72  46  64 /  10  10   0   0  30  30 
Moses Lake     49  81  51  80  51  76 /   0   0   0   0  10  10 
Wenatchee      55  79  57  78  54  75 /   0   0   0   0  10  10 
Omak           51  78  54  77  51  75 /   0   0   0  10  20  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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