Strong Wind in Washington, January 23 to 24, 2014

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
938 AM PST THU JAN 23 2014

.SYNOPSIS...HIGH PRESSURE HAS RETURNED OVER THE AREA AND GUSTY EAST
WINDS WILL CLEAR SKIES FOR MOST AREAS TODAY AND FRIDAY. THE EAST
WINDS WILL DECREASE OVER THE WEEKEND WITH VALLEY FOG AND LOW CLOUDS
RETURNING. THERE IS A CHANCE FOR LIGHT RAIN EARLY NEXT WEEK.

&&

.SHORT TERM UPDATE...EASTERLY WINDS HAVE INCREASED ATMOSPHERIC MIXING
AND THE THE AIR QUALITY IN THE INLAND VALLEYS IS IMPROVING. HAVE
THEREFORE CANCELLED THE AIR STAGNANT ADVISORY WITH THE MORNING
UPDATE. THE TROUTDALE TO DALES SURFACE PRESSURE GRADIENT IS AROUND
-8.0 MB THIS MORNING AND WILL INCREASE TO AROUND 10 MB IN THE
AFTERNOON. GUSTY WINDS WILL MOVE THROUGH THE GORGE AND ACROSS THE
HIGHER TERRAIN AS WELL AS THROUGH SOME OF THE MOUNTAIN GAPS. GUSTS
AROUND 40 MPH ARE EXPECTED IN THE PORTLAND METRO AREA AND AROUND THE
ENTRANCE TO THE COLUMBIA RIVER GORGE THIS AFTERNOON. THE CENTRAL AND
SOUTHERN VALLEY MAY HAVE NORTHERLY GUSTS AROUND 25 MPH. THERE WILL BE
LOCALLY HIGHER GUSTS AT THE WINDIER LOCATIONS IN THE GORGE AND NEAR
TROUTDALE BUT THESE HIGHER WINDS WILL BE LOCALIZED.

AN UPPER RIDGE OF HIGH PRESSURE WILL CONTINUE TO BUILD TONIGHT AND
HOLD AROUND 582 DAMS THROUGH FRIDAY. LOWER PRESSURE SW OF THE AREA
WILL MAINTAIN EAST TO NORTHEAST WINDS THROUGH FRIDAY. IN FACT THERE
WILL BE VERY LITTLE CHANGE IN WEATHER THE 48 HOURS. EXPECT SOME FOG
TO DEVELOP OVER NIGHT IN AREAS FAR FROM THE INFLUENCE OF THE EASTERLY
WINDS LIKE EUGENE...SCAPOOSE...AND KELSO. THE FOG MAY BE DENSE IN
THESE LOCATIONS...BUT WILL IMPROVE FRIDAY AFTERNOON.

MOST AREAS WILL BE SUNNY TODAY AND FRIDAY BUT THE COOLING
EFFECT OF THE WINDS WILL OFFSET SOME OF THE ADDED WARMING FROM THE
SUN. THE EASTERN PORTION OF THE GORGE AND THE UPPER HOOD RIVER VALLEY
WILL STAY ON THE COOL SIDE DUE COLD AIR EAST OF THE CASCADES BANKING
INTO THOSE AREAS. THESE AREAS WILL ALSO LIKELY REMAIN CLOUDY.

THE RIDGE WILL WEAKEN FRIDAY NIGHT AND SATURDAY...BUT SHARPEN AS LOW
PRESSURE DEVELOPS IN THE NE PACIFIC. THIS WILL STRENGTHEN THE
TEMPERATURE INVERSION AND  FOG/STRATUS WILL RETURN TO THE INLAND
VALLEYS. HARTLEY

.LONG TERM...SUNDAY NIGHT THROUGH WEDNESDAY...VALLEY FOG WILL BE THE
MAIN WEATHER FEATURE SUNDAY NIGHT INTO MONDAY MORNING. THE MODELS ARE
TRYING TO PUSH A WEAK FRONT ACROSS THE REGION MONDAY NIGHT AND
TUESDAY. IF THIS PANS OUT THE FRONT WILL WEAKEN AS IT NEARS AND
EXPECT ONLY LIGHT...LOW ACCUMULATING RAIN. THERE IS SOME CONCERN THAT
THE MODELS MAY BE PUSHING THE RIDGE EASTWARD TOO QUICKLY AS ANOTHER
UPPER LOW OVER THE NE PORTION OF THE COUNTRY MAY RESULT IN AN OMEGA
BLOCK THAT WOULD KEEP THE PACIFIC NW DRY THROUGH AT LEAST TUESDAY.
THE MODELS DO HINT THAT THE RIDGE WILL FLATTEN BY WEDNESDAY WHICH MAY
ALLOW SOME SYSTEMS TO COME THROUGH TOWARDS THE END OF THE WEEK.
MODELS ARE HINTING OF A MUCH COLDER SYSTEM TOWARDS THE END OF NEXT
WEEK. HARTLEY

&&

.AVIATION...STRONG OFFSHORE FLOW SHOULD RESULT IN MAINLY VFR
CONDITIONS AND GUSTY WINDS TODAY. WINDS SHOULD DROP OFF ENOUGH
AFTER 06Z FRIDAY THAT KEUG AND POSSIBLY KSLE MAY SEE CONDITIONS
DETERIORATE INTO IFR CONDITIONS TOWARDS 12Z FRIDAY WHERE THEY
WILL LIKELY PERSIST THROUGH ABOUT 18Z FRIDAY.

KPDX AND APPROACHES...VFR CONDITIONS WITH GUSTY EAST WINDS THROUGH
18Z FRIDAY. THERE IS A 20 PERCENT CHANCE IFR CONDITIONS COULD CREEP
INTO THE TERMINAL FROM THE NORTHWEST TOWARDS 15Z FRIDAY. /NEUMAN

&&

.MARINE...INCREASING NORTHEASTERLY WINDS TODAY AS HIGH PRESSURE
BUILDS OVER THE WATERS. MEANWHILE...THERMALLY-INDUCED LOW PRESSURE
ALONG FAR S OREGON COAST WILL EXPAND N TODAY. END RESULT WILL BE
GUSTY E TO NE WIND...UP TO 25 KT. WINDS BECOME MORE EASTERLY TONIGHT
THROUGH SATURDAY...WITH THE STRONGEST WINDS ADJACENT TO GAPS IN THE
COASTAL TERRAIN AND OFFSHORE TO THE S.

SEAS HOLD AROUND 7 TO 8 FT THIS MORNING...THEN EXPECT A LONG
PERIOD SWELL TO ARRIVE THIS AFTERNOON AND EVENING...WITH SEAS
BUILDING TONIGHT INTO FRIDAY AND PEAKING AROUND 12 FT...THEN
EASING LATER FRI. QUIET CONDITIONS THROUGH THE WEEKEND WITH THE
NEXT SWELL ABOVE 10 FT NOT EXPECTED UNTIL TUESDAY AS A LOW
PRESSURE SYSTEM PASSES BY TO THE NORTH WELL OFFSHORE.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 AM PST FRIDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 3 PM THIS
     AFTERNOON TO 9 PM PST FRIDAY FROM CAPE	SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
     MIDNIGHT PST TONIGHT.

&&

MORE WEATHER INFORMATION ONLINE AT..
    HTTP://WEATHER.GOV/PORTLAND

INTERACT WITH US VIA SOCIAL MEDIA
    WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
    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.