FXUS66 KPQR 302244
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
159 PM PST MON NOV 30 2009

.SYNOPSIS...A WEAK FRONT DRAGGING ACROSS THE NORTHERN ZONES WILL
BRING A SLIGHT CHANCE FOR RAIN...MAINLY IN THE WASHINGTON ZONES
THROUGH THIS EVENING.  AN UPPER LEVEL RIDGE BUILDING OFFSHORE WILL
MOVE TO NEAR THE COAST TUESDAY AND WEDNESDAY. THIS WILL LEAVE THE
AREA DRY WITH INLAND VALLEY INVERSION CONTINUING...FOR SOME FOG AND
LOW CLOUDS. OFFSHORE WILL BEGIN TO INCREASE TUESDAY COOL AIR SETTLES
EAST OF THE CASCADES. STRONGER OFFSHORE FLOW MAY ARRIVE THIS WEEKEND
AS HIGH PRESSURE MOVES EAST OF THE CASCADES.

&&

.SHORT TERM...STRATUS AND FOG HOLDING STRONG OVER THE INLAND VALLEYS 
THIS AFTERNOON. A WEAK FRONT DRAGGING ACROSS WESTERN WASHINGTON IS 
BRINGING SOME LIGHT RAIN TO HOQUIAM AND LONG BEACH WITH SOME DRIZZLE 
IN THE ASTORIA AREA.  WILL KEEP SLIGHT CHANCE POPS FOR THE 
WASHINGTON ZONES AND NORTH OREGON COAST THIS EVENING...AND INTRODUCE 
SOME LIGHT DRIZZLE AS WELL.  ALSO WITH PERSISTENT INLAND INVERSION 
HAVE INCREASED FOG AND CLOUD COVERAGE AS WELL. STRONGER HIGH PRES 
SLIDES INTO THE NORTHERN ROCKIES TUE AND WED FOR INCREASING EASTERLY 
WINDS CROSSING THE CASCADES AND THROUGH THE COLUMBIA RIVER GORGE. 
THIS SHOULD BRING ENOUGH MIXING AND DRYING ESPECIALLY IN THE 
NORTHERN WILLAMETTE VALLEY NEXT COUPLE OF DAYS TO LIMIT FOG 
FORMATION. MODELS STILL IN BASIC AGREEMENT WITH RIDGE SHIFTING OVER 
WESTERN WASHINGTON AND OREGON AS SOME SHORTWAVE ENERGY MOVES INTO 
BRITISH COLUMBIA. HOWEVER EFFECTS OF THE RIDGING CONTINUES INTO THU 
SO HAVE CUT POPS THEN. BOTTOM LINE...DRY AND COOL WITH SOME FOG AND 
STRATUS IN THE VALLEYS THROUGH AT LEAST MID WEEK.

.LONG TERM...12Z ECMWF AND GFS OPERATIONAL RUNS CONTINUE TO SHOW 
DISTINCTLY DIFFERENT SOLUTIONS THAT PERSIST THROUGH THE EXTENDED 
PERIOD. LOOKING OVER SPAGHETTI CHARTS FOR GFS ECMWF AND CANADIAN 
LENDS SUPPORT TO BOTH TYPES OF SOLUTIONS...EITHER A TROUGH INLAND 
WITH A RIDGE OFFSHORE...OR A CUTOFF LOW LINGERING OVER THE PACNW. 
GIVEN CONTINUED UNCERTAINTY...WILL MAKE LITTLE CHANGE TO FORECAST 
FOR THE TIME BEING.

&&

.AVIATION...GENERALLY IFR CONDITIONS OVER MUCH OF THE AREA AND WILL 
LIKELY STAY IFR IN THE S WILLAMETTE VALLEY THROUGH THIS AFTERNOON. 
OTHER AREAS WILL LIKELY RETURN TO VFR OR MVFR CEILINGS BY THE 
AFTERNOON AS A BIT OF ONSHORE FLOW AHEAD OF A WEAK FRONT MIXES THE 
BOUNDARY LAYER UP.

KPDX AND APPROACHES...IFR CIGS SHOULD CONTINUE THROUGH 18Z...THEN 
MVFR CONDITIONS ARE EXPECTED THEREAFTER AS A WEAK FRONT DROPS SE 
THROUGH THE AREA.

.MARINE...WINDS WILL REMAIN BELOW SMALL CRAFT LEVELS FOR THE NEXT 
SEVERAL DAYS. SEAS WILL REMAIN HIGH...GENERALLY BETWEEN 14 AND 17 FT 
THROUGH TODAY. SEAS SHOULD SUBSIDE TONIGHT THEN FALLING BELOW 10 FT 
BY TUE MORNING. 

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST TUE
       FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR.
     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 AM
       PST TUE.

&&

$$

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.