FXUS66 KPQR 081055
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
255 AM PST TUE DEC  8 2009

.SYNOPSIS...A MODIFIED ARCTIC AIR MASS WILL CONTINUE THROUGH
WEDNESDAY. AREAS OF GUSTY NORTHEAST WINDS WILL CONTINUES TO TAPER OFF
TODAY AND TONIGHT. COLD DRY WEATHER WILL PERSIST THROUGH FRIDAY.
PRECIPITATION CHANCES WILL INCREASE AGAIN THIS WEEKEND WITH THE
POSSIBILITY OF PRECIPITATION BRIEFLY BEGINNING AS A WINTERY MIX.

&&

.SHORT TERM...WINDS CONTINUE TO DECREASE BUT MESOWEST STILL SHOWS A
SWATH OF ABOUT 20 KT EASTERLY WINDS FROM THE WEST GORGE INTO THE
COAST RANGE AND ON TO THE CENTRAL COAST. ANOTHER SHORTWAVE TROUGH
WILL ARRIVE FROM THE N EARLY TODAY...THEN DROP S OF THE REGION BY
TONIGHT. THERE WILL BE JUST SOME MID/HIGH CLOUDS WITH THIS SYSTEM.
THE MAIN EFFECT WILL BE TO TURN THE 850 MB FLOW MORE NORTHERLY TODAY
WHILE THE LOW LEVELS REMAIN RATHER LIGHT OFFSHORE. WINDS WILL
EVENTUALLY BE CONFINED TO THE WESTERN GORGE BY TONIGHT. 

CALMER AND MORE STABLE CONDITIONS IN MUCH OF THE COAST AND INLAND
VALLEYS TONIGHT AND WED MORNING WILL LIKELY BRING COLDER SURFACE
TEMPERATURES TO LOW LYING INVERSION PRONE AREAS WHERE SOME WIND HAS
PERSISTED EARLY TODAY. GUIDANCE SHOWS THE LOW LEVEL FLOW BECOMING 
NEUTRAL BY WED AFTERNOON EXCEPT FOR A LITTLE OFFSHORE DRIFT POSSIBLY
CONTINUING IN THE W GORGE. WITH MINIMAL OFFSHORE FLOW AND A SLOWLY
WARMING AIR MASS ALOFT WE SHOULD SEE SLIGHTLY WARMER DAYTIME
TEMPERATURES BY THU. RW

.LONG TERM...DRY CONDITIONS WILL PREVAIL INTO FRI AS NW FLOW ALOFT
CONTINUES OVER THE REGION. MODELS AGREE THAT THE NEXT SYSTEM FROM THE
PAC SHOULD ARRIVE AROUND FRI NIGHT/EARLY SAT WITH PRECIP CHANCES
INCREASING. THE BIGGEST THREAT OF FREEZING RAIN OR MIXED PRECIP FOR
THE EASTERN PORTION OF THE CWA WILL BE THIS INITIAL TRANSITION.
EXPECT WET BUT WARMER CONDITIONS TO PERSIST AT TIMES FOR THE
REMAINDER OF THE WEEKEND INTO THE FOLLOWING WEEK AS SW FLOW FROM THE
PAC PERSISTS. RW/LRAMIREZ

&&

.AVIATION...DRY OFFSHORE FLOW IS EXPECTED THROUGH THE NEXT 24 HOURS 
WITH VFR CONDITIONS. GUSTY EAST WINDS EXPECTED THROUGH GAPS IN 
TERRAIN.

KPDX AND APPROACHES...VFR CONDITIONS ARE EXPECTED THROUGH THE NEXT 
24 HOURS. GRADIENTS RELAX TONIGHT FOR CALMER CONDITIONS...THOUGH 
LIGHT EASTERLY WINDS MAY CONTINUE THROUGH WED MORNING.

&&

.MARINE...MAIN CONCERN FOR THE NEXT DAY OR TWO IS THE INCREASING 
SWELLS FOR TODAY AND WED. BUILDING WEST SWELL FROM AN ALEUTIAN STORM 
SYSTEM WILL CAUSE SEAS TO EXCEED 10 FT IN OUR OUTER WATERS BY MIDDAY 
TODAY...WITH THE SWELL SPREADING TO THE COASTLINE BY THIS EVENING. 
WEST SWELL 10-12 FT IS EXPECTED TO AFFECT THE COASTAL WATERS THROUGH 
WED...BEFORE SUBSIDING BELOW 10 FT WED EVENING. THE SWELL IS FAIRLY 
LONG IN PERIOD...AROUND 20 SECONDS...AND SHOULD RESULT IN ROUGH BAR 
CONDITIONS STARTING AROUND 7 PM THIS EVENING AND PEAKING AROUND THE 
945 PM EBB TONIGHT. ALSO...ROUGH BAR CONDITIONS SHOULD LAST THROUGH 
THE NIGHT AS SWELLS CONTINUE TO INCREASE AND PERIODS REMAIN HIGH. ON 
THE WIND FRONT...HIGH PRESSURE SHOULD KEEP WINDS RELATIVELY LIGHT 
THROUGH FRI...AFTER WHICH THERE IS THE POTENTIAL FOR A STRONGER LOW 
TO AFFECT THE COASTAL WATERS SOMETIME FRI NIGHT OR SATURDAY.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR/WA...SCA FOR HAZARDOUS SEAS CAPE SHOALWATER TO FLORENCE OUT 10-60 
	 NM OFFSHORE MIDDAY TODAY THROUGH EARLY WED MORNING.
	SCA FOR HAZARDOUS SEAS CAPE SHOALWATER TO FLORENCE OUT 10 NM 
	 TONIGHT THROUGH WED MORNING.
	SCA FOR ROUGH COLUMBIA BAR 7 PM TONIGHT THROUGH EARLY WED    
	 MORNING.

&&

$$

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.