AREA FORECAST DISCUSSION

 
 FXUS66 KPQR 221639
 AFDPQR
 
 AREA FORECAST DISCUSSION
 NATIONAL WEATHER SERVICE PORTLAND OR
 839 AM PST SUN NOV 22 2009
 
 .SYNOPSIS...A STRONG SURFACE LOW OVER WESTERN WASHINGTON THIS MORNING
 WILL CONTINUE TO MOVE EAST TODAY AND WEAKEN. HIGH PRES WILL BUILD IN
 OVER WESTERN OREGON LATER TODAY AND TONIGHT. A WARM FRONT OFF THE
 COAST ON MON WILL LIFT NE TOWARDS NW OREGON AND WESTERN WA....THEN
 STALL ON TUE. WED THE FRONT WILL FINALLY LIFT N INTO WA...BEFORE A
 COLD FRONT PUSHES SE THROUGH THE REGION THU.
 &&
 
 .SHORT TERM...SATELLITE IMAGERY SHOWS THE LOW PRESSURE SYSTEM THAT
 CAME ONSHORE OVERNIGHT NEAR WILLAPA BAY IS NOW IN WESTERN WASHINGTON
 NEAR 48N 123W. THE ASSOCIATED OCCLUDED FRONT ARCS JUST EAST OF THE
 OREGON CASCADES. WINDS OVER THE FORECAST AREA ARE BELOW WARNING
 CRITERIA...HOWEVER THERE ARE STILL STRONG WESTERLY WINDS ON THE
 BACKSIDE OF THE FRONT WITH WINDS STILL GUSTING IN THE 40S ALONG THE
 COAST.
 
 DOPPLER RADAR SHOWING GOOD SHOWER ACTIVITY OVER THE FORECAST AREA
 THIS MORNING. CASCADES HAVE ALREADY RECEIVED 8 TO 12 INCHES OF NEW
 SNOW OVERNIGHT. STRONG OROGRAPHIC WESTERLY FLOW WILL KEEP SHOWERS
 GOING THIS MORNING...AND WILL KEEP THE WINTER STORM WARNING GOING
 TODAY. OROGRAPHICS WEAKEN THIS AFTERNOON AS H8 FLOW WEAKENS...SO WE
 SHOULD SEE SNOW ACCUMULATIONS DROP OFF CONSIDERABLY THIS AFTERNOON. 
 
 POST FRONTAL SHOWERS DROP OFF QUICKLY TONIGHT...LAST ON THE N PART OF
 THE CASCADES. AN AREA OF WARM AIR ADVECTION SETS UP OVER THE NW PART
 OF THE FORECAST AREA MON...AND CONTINUES INTO TUE. A WEAK SHORTWAVE
 MOVES ACROSS THE TOP OF THE DEVELOPING UPPER RIDGE TUE...BRINGING THE
 BEST CHANCE FOR OVERRUNNING PRECIPITATION TO THE NW PART OF THE AREA
 ON TUE.
 
 .LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...WEAK HIGH PRES
 RIDGE OVER THE FORECAST AREA CONTINUES TO PUSH ENERGY NORTH OF
 FORECAST AREA MID WEEK. IT MANAGES TO DELAY THE ARRIVAL OF A SECOND
 SYSTEM THROUGH THUR. MODEL SOLUTIONS DIVERGE TOWARD THE END OF THE
 WEEK AND HAVE LITTLE CONFIDENCE IN THEM. AT THIS TIME WILL GO WITH
 CLIMATOLOGY UNTIL THERE IS SOME CONSISTENCY BETWEEN THE MODELS..
 &&
 
 .AVIATION...STRONG FRONT NOW PUSHING INTO EASTERN OREGON...WITH 
 MOSTLY VFR CONDITIONS. PLENTY OF SHOWERS TO PUSH INLAND THIS 
 MORNING...WITH OCCASIONAL MVFR. GUSTY SOUTHWEST WINDS WILL EASE 
 GRADUALLY BETWEEN NOW AND 18Z.
 
 KPDX AND APPROACHES...VFR TODAY...BUT EXPECT OCCASIONAL MVFR CIGS 
 DOWN TO 2000 FT WITH SHOWERS...ESPECIALLY THIS MORNING. GUSTY SOUTH 
 TO SOUTHWEST WINDS WILL CONTINUE UNTIL 17Z...THEN GRADUALLY EASE. 
 WOLFE
 &&
 
 .MARINE...WORST IS OVER...BUT STILL A LOT OF GRADIENT ON BACK SIDE 
 OF THE LOW.  WINDS STILL HITTING 40 KT...WILL MAINTAIN SOLID GALES 
 THROUGH EARLY AFTERNOON. SEAS TOPPING AROUND 22 TO 24 FT THIS 
 AM...BUT WILL EASE TO THE MID TO LOWER TEENS BY TONIGHT. NEXT SYSTEM 
 WILL MOVE ACROSS THE COASTAL WATERS ON MON...WITH NEAR GALE FORCE 
 WINDS. DIFFERENCE IS THAT THE PARENT LOW WILL PASS MUCH FURTHER TO 
 THE N OF THE AREA. WOLFE
 
 &&
 
 .PQR WATCHES/WARNINGS/ADVISORIES...
 WA/OR...GALE WARNING FOR THE COASTAL WATERS FROM CAPE SHOALWATER TO  
   FLORENCE UNTIL NOON TODAY.  
 SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA BAR CONDITIONS 
   THROUGH SUN NIGHT.
 WINTERSTORM  WARNING FOR THE S WA AND N AND CENTRAL OREGON
   CASCADES TODAY.
 
 
 &&
 
 $$
 
 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.