Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 241054
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
254 AM PST MON NOV 24 2014

.SYNOPSIS...THE FRONTAL ZONE AND ASSOCIATED PRECIPITATION HAS
DISSIPATED OVER THE FORECAST AREA EARLY THIS MORNING. WEAK HIGH
PRESSURE WILL LIKELY KEEP MUCH OF THE FORECAST AREA DRY THROUGH THIS
MORNING...BUT A WARM FRONT IS EXPECTED TO BRING MORE RAIN WITH RISING
SNOW LEVELS TO THE DISTRICT BY THIS EVENING. ANOTHER DISTURBANCE WILL
LIKELY RIDE ALONG THIS FRONT TUESDAY...BRINGING MORE RAIN TO
SOUTHWEST WASHINGTON WHILE THE CENTRAL AND SOUTHERN WILLAMETTE VALLEY
DRY OUT. AFTER A MAINLY DRY DAY WEDNESDAY...THE NEXT FRONTAL SYSTEM
IS EXPECTED TO ARRIVE THANKSGIVING DAY FOLLOWED BY MORE UNSETTLED
WEATHER THROUGH THE HOLIDAY WEEKEND.

&&

.SHORT TERM...TODAY THROUGH THANKSGIVING DAY...OVERALL SHOWERS HAVE
DISSIPATED ACROSS THE REGION...WITH THE EXCEPTION OF A FEW LINGERING
SHOWERS OVER THE CENTRAL COAST AND COAST RANGE AS SEEN ON KRTX RADAR
EARLY THIS MORNING. HIGH PRESSURE OVER THE EASTERN PACIFIC WILL
CONTINUE TO STRENGTHEN THIS MORNING...WITH SOME PATCHY FOG DEVELOPING
ACROSS THE INLAND VALLEYS AND LOCALLY ALONG THE COAST. STILL NOT
EXPECTING FOG TO BECOME DENSE...BUT SOME LOCALIZED SPOTS OF DENSE FOG
ARE MORE LIKELY. ANY FOG THAT DOES DEVELOP SHOULD BURN OFF BY 10-11AM
PST THIS MORNING...DUE TO INCREASING CLOUDS AHEAD OF A WARM FRONT
EXPECTED TO REACH THE PACIFIC NORTHWEST LATE THIS AFTERNOON AND
EVENING. THIS MAY PRODUCE A BIT OF ISENTROPIC LIFT AND OVERRUNNING
PRECIPITATION TONIGHT.

ANOTHER VORTMAX IS EXPECTED TO RIDE ALONG THIS FRONT EARLY TUESDAY
MORNING... WITH THE 06Z GFS AND NAM SHOWING A CONSIDERABLE AMOUNT OF
QPF OVER SW WASHINGTON AS IT TAPS INTO A MODEST ATMOSPHERIC RIVER.
HAVE UPPED QPF AMOUNTS OVER THE SW WASHINGTON CASCADES IN
PARTICULAR...WITH 1-3 INCHES EXPECTED. SNOW LEVELS ARE LIKELY TO HAVE
RISEN ABOVE 6000 FT BY THAT POINT.

BY THEN THE UPPER RIDGE WILL LIKELY BE DOMINANT SALEM SOUTHWARD...
WITH SOME FOG FORMING TUE NIGHT/WED MORNING IN THE VALLEYS. DESPITE
AN UNSEASONABLY WARM AIR MASS ALOFT...WITH 850 MB TEMPS UPWARDS OF
+10 DEG C WED...THE VALLEYS WILL LIKELY BE STUCK IN A BIT OF AN
INVERSION THUS LIMITING TEMPS SOMEWHAT. MAX TEMP FORECAST FOR WED
AFTERNOON WILL BE TRICKY AS A RESULT. IT DOES APPEAR WED WILL BE DRY
FOR MOST OF THE DISTRICT AS UPPER RIDGING TAKES CHARGE.

MODELS ARE COMING IN BETTER AGREEMENT WITH THE PACIFIC FRONTAL SYSTEM
EXPECTED FOR EARLY THANKSGIVING DAY. LOOKS LIKE RAIN WILL REACH THE
COAST BY MIDNIGHT WEDNESDAY...PUSHING INLAND THROUGH NOON
THANKSGIVING DAY. EXPECT THE FRONT TO PUSH THROUGH MIDDAY
THURSDAY...WITH RAIN LIKELY ACROSS THE ENTIRE AREA. WEAGLE/27

.LONG TERM...THURSDAY NIGHT THROUGH MONDAY..LINGERING SHOWERS WILL
PERSIST THROUGH THE REMAINDER OF THANKSGIVING DAY AS A PACIFIC
FRONTAL SYSTEM DRIFTS SOUTHEAST ACROSS THE FORECAST AREA. A SECOND
DISTURBANCE WILL QUICKLY TAKE THE DEPARTING FRONTS PLACE EARLY FRIDAY
MORNING...AS THE MAIN UPPER LEVEL TROUGH DIGS FURTHER INTO CANADA.
MODELS ARE HINTING ANOTHER COLD AIR MASS WILL SET UP OVER EASTERN
OREGON SATURDAY...WITH HIGH PRESSURE DEVELOPING EAST OF THE CASCADES
AND LOW PRESSURE SETTING UP JUST OFF THE OREGON/CALIFORNIA COAST.
OFFSHORE FLOW WILL DEVELOP...BRINGING BREEZY EAST WINDS THROUGH THE
COLUMBIA RIVER GORGE FOR NEXT WEEKEND. /27

&&

.AVIATION...LOW LEVEL CLOUDS THIS MORNING ARE KEEPING AREAS MVFR
WILL OCCASIONAL IFR THIS MORNING. WIND IS KEEPING KEUG AND KSLE VFR
LONGER THAN ANTICIPATED. MODELS ARE HINTING THAT THIS WIND MAY
PUSH NORTHWARD WITH TIME THIS MORNING...WHICH COULD CLEAR OUT THE
LOW-LEVEL STRATUS. THIS COULD LIFT CIGS AND VISIBILITY TO VFR
ACROSS THE WILLAMETTE VALLEY BY 18-21Z. COASTAL SITES ARE
REMAINING VFR CURRENTLY...THOUGH CALM WINDS WILL ALLOW FOG TO
DEVELOP SOON. EXPECT THESE SITES TO DEVELOP MVFR/IFR CIGS AND
VISIBILITY OVER THE NEXT HOUR OR TWO...AND LIKELY WILL NOT CLEAR
UNTIL WINDS PICK UP OUT OF THE SOUTH AROUND 15-18Z.

ANOTHER WEAK FRONT MOVES THROUGH THIS AFTERNOON AROUND
00Z...WHICH COULD BRING CIGS AND VISIBILITY DOWN TO MVFR THIS
EVENING WITH RAIN.

KPDX AND APPROACHES...LOW STRATUS KEEPING CIGS MVFR THIS MORNING.
LOW STRATUS LOOKS TO CLEAR OUT AROUND 16-18Z THIS MORNING BEFORE
COLD FRONT MOVES THROUGH THIS AFTERNOON. RAIN WILL LIKELY BRING
CIGS BACK DOWN TO MVFR THIS EVENING AROUND 00Z. -MCCOY

&&

.MARINE...A WEAK FRONT WILL MOVE THROUGH THE WATERS TODAY...BRINGING
SOUTHERLY WINDS BACK ABOVE 20 KT GUSTING TO 30 KT LATER THIS MORNING.
THESE SHOULD DECREASE THIS EVENING AS THE FRONT MOVES ONSHORE AND
WINDS SHIFT TO WESTERLY. SEAS LOOK TO REMAIN AROUND 10 TO 12 FT
TODAY...ONLY DROPPING BELOW 10 FT EARLY TUESDAY BEHIND THIS FRONT.
ANOTHER WEAK FRONT LOOKS TO MOVE THROUGH OUR WATERS ON
TUESDAY...WHICH COULD BRING WINDS AND SEAS BACK UP TO SMALL CRAFT
CRITERIA. AS OF NOW...THIS LOOKS TO MAINLY IMPACT OUR NORTHERN
WATERS...THOUGH SOUTHERN WATERS LOOK TO GET CLOSE TO 10 FT SEAS. SEAS
DROP BACK BELOW 10 FT ON WEDNESDAY. ACTIVE WEATHER PATTERN BRINGS
ANOTHER FRONT IN WEDNESDAY NIGHT OR THURSDAY WHICH AS OF NOW LOOKS TO
AGAIN INCREASE WINDS AND SEAS TO SMALL CRAFT CRITERIA. -MCCOY


&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 10 AM THIS MORNING TO 10 PM
     PST THIS EVENING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
    FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 4 AM PST TUESDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
    60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 4 AM
    PST TUESDAY.

&&

$$

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.



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