Area Forecast Discussion
Issued by NWS Portland, OR

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066
FXUS66 KPQR 141109
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
309 AM PST SUN FEB 14 2016

.SYNOPSIS...A WARM FRONT WILL REMAIN OVER SOUTHWEST WASHINGTON AND
NORTHWEST OREGON TODAY...SLOWLY LIFTING NORTH INTO WESTERN WASHINGTON
TONIGHT AND MONDAY WITH RAIN DECREASING FROM THE SOUTH AS AN UPPER
RIDGE BUILDS SOME ALONG THE WEST COAST. THE FRONT WILL SAG BACK SOUTH
INTO SOUTHWEST WASHINGTON AND FAR NORTHWEST OREGON TUESDAY AS A COLD
FRONT...THEN LIFT BACK NORTH AND WEAKEN AS A WARM FRONT FOR DRYING
AGAIN TUESDAY NIGHT. THE COLD FRONT WITH THE NEXT SYSTEM WILL
APPROACH THE PACIFIC NORTHWEST WEDNESDAY THEN MOVE THROUGH THE
FORECAST AREA WEDNESDAY NIGHT INTO THURSDAY WITH LOWERING SNOW LEVELS
IN THE CASCADES THURSDAY. ANOTHER PACIFIC FRONT IS EXPECTED FRIDAY.
&&

.SHORT TERM...A WARM FRONT MOVED INTO SOUTHWEST WASHINGTON AND
NORTHWEST OREGON SATURDAY WHICH WILL LINGER OVER THE AREA TODAY. THE
FIRST AND STRONGEST WAVE MOVED THROUGH SATURDAY EVENING WITH A PERIOD
OF RATHER HEAVY RAIN OVER THE AREA AS PRECIPITABLE WATER VALUES OF
AROUND 1.2 INCHES WERE FED INTO THE AREA BY 50 KT 850 MB WINDS.

THIS WAVE MOVED EASTWARD AND THE RAIN LET UP FOR A WHILE OVERNIGHT
SATURDAY NIGHT...BUT NOW THE NEXT WAVE HAS BEGUN MOVING INTO THE
AREA EARLY THIS MORNING AND WILL CONTINUE OVER OUR FORECAST AREA
THIS MORNING. AMOUNTS WILL BE GOOD...BUT LESS THAN THOSE SATURDAY
EVENING AS 850 MB WINDS WILL BE BETWEEN 30 AND 40 KT THIS MORNING.

TEMPS IN THE SOUTH WASHINGTON AND FAR NORTH OREGON CASCADES ARE
STILL SUPPORTING SNOW DOWN TO AROUND 4500 OR 5000 FEET THIS
MORNING...AND WILL EXTEND THE SNOW ADVISORY UNTIL 9 AM. EXPECT SNOW
LEVELS TO RISE WELL ABOVE ALL THE PASSES BY THEN.

500 MB HEIGHTS WILL START TO BUILD SOME LATER TODAY AND TONIGHT...
BEGINNING TO PUSH THE WARM FRONT SLOWLY NORTH OF OUR AREA WITH RAIN
DECREASING FROM THE SOUTH TONIGHT AND MONDAY. ON MONDAY...THE MAIN
CHANCE OF ANY RAIN WILL BE ACROSS OUR NORTHERN ZONES...MAINLY
PORTLAND NORTHWARD OR SO. WITH THE WARM FRONT MAINLY NORTH OF OUR
AREA MONDAY...WE WILL BE IN THE WARM SECTOR AND AFTERNOON TEMPS IN
THE VALLEYS HAVE A CHANCE OF REACHING THE UPPER 50S TO MID 60S AGAIN.

THE WARM FRONT WILL REVERSE COURSE AND BEGIN TO SAG SOUTH INTO THE
NORTH PART OF OUR FORECAST LATE MONDAY NIGHT AND ON TUESDAY.
HOWEVER...THE MODELS HAVE HAD TROUBLE WITH THE DETAILS OF THIS IDEA.
THE CURRENT CROP OF MODELS ARE SUGGESTING THE RAIN COULD SPREAD SOUTH
TO AROUND A PACIFIC CITY TO WILSONVILLE LINE OR SO BEFORE STALLING.
THE MODELS ARE THEN INDICATING THE FRONT WILL PLAY YO YO AND LIFT
BACK NORTH AS A WARM FRONT AS IT WEAKENS LATE TUESDAY AND TUESDAY
NIGHT FOR MORE DRYING FROM SOUTH TO NORTH. TOLLESON

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
TUESDAY NIGHT THROUGH FRIDAY...THE UPPER RIDGE RESPONSIBLE FOR THE
DRYING TREND MON/TUE WILL SHIFT EAST MIDWEEK... WITH MODELS SHOWING
GOOD CONSENSUS IN BRINGING A WELL DEFINED UPPER TROUGH INTO THE PAC
NW AND POSSIBLY CALIFORNIA WED NIGHT/THU. THIS WILL CAUSE RAIN
CHANCES TO INCREASE LATER WED...WITH COOL AND SHOWERY WEATHER
LINGERING INTO THU. AIR MASS WILL START OUT RATHER WARM WITH SNOW
LEVELS WELL ABOVE THE CASCADE PASSES WED. COLDER AIR WILL MOVE IN
WITH THE UPPER TROUGH...WITH SNOW LEVELS LOWERING TO 3000 TO 3500
FEET IN SHOWERS BY THURSDAY. EXPECT TEMPS TO DROP BACK TO NEAR NORMAL
LATE WEEK AS A RESULT OF THE UPPER TROUGH...POSSIBLY EVEN A LITTLE
BELOW NORMAL. MODELS SHOW DECENT AGREEMENT THAT THIS UPPER TROUGH
WILL BE FOLLOWED BY A MORE PROGRESSIVE FRONTAL SYSTEM FOR MORE RAIN
AND CASCADE SNOW FRI/FRI NIGHT.  WEAGLE
&&

.AVIATION...ANOTHER BATCH OF WARM FRONTAL RAIN IS NOW AFFECTING THE
AREA. FLIGHT CONDITIONS VARY WIDELY ACROSS THE AREA THIS MORNING WITH
IFR/LIFR ON THE COAST AND MVFR INLAND. THERE IS MORE VFR BETWEEN KSLE
AND KEUG AS OF 10Z BUT WILL PROBABLY SEE MORE WIDESPREAD MVFR IN THAT
AREA THIS MORNING THROUGH AFTERNOON AS THE RAIN EXTENDS FURTHER
SOUTH. EXPECT CONDITIONS TO IMPROVE TO A MIX OF VFR AND MVFR THIS
EVENING AS THE WARM FRONT LIFTS NORTH OF THE AREA. HOWEVER MOIST
STABLE SOUTHWEST FLOW MAY LIMIT IMPROVEMENT AT THE COAST TO THE MVFR
CATEGORY. EXPECT THE MOUNTAINS TO REMAIN OBSCURED THROUGH TONIGHT AS
850 MB FLOW RESULTS IN ENHANCED OROGRAPHIC LIFT.

KPDX AND APPROACHES...MVFR CIGS AROUND 1500 TO 2000 FT LIKELY TO
CONTINUE THROUGH 00Z MON. THEN BETTER CHANCES FOR HIGH END MVFR TO
VFR TONIGHT.
&&

.MARINE...ANOTHER WARM FRONT AFFECTING THE AREA TODAY AND BRING SMALL
CRAFT ADVISORY WINDS AND SEAS ACROSS THE AREA. AS OF 2 AM WINDS HAVE
EASED OVER THE WATERS NORTH OF CASCADE HEAD BUT WILL INCREASE THIS
MORNING. HOWEVER NEAR SHORE WATERS SOUTH OF CASCADE HEAD REMAINED
GUSTY OVERNIGHT WITH OCCASIONAL GUST TO AROUND 35 KT. WIND HAVE BEGUN
TO EASE AS MODELS SHOW SO EXPECT WINDS TO REMAIN IN THE ADVISORY
CATEGORY THROUGH TODAY. WINDS EASE LATE TODAY AND TONIGHT. MARGINAL
SMALL CRAFT ADVISORY WINDS FOR THE NORTHERN WATERS PARTICULARLY FROM
20 TO 60 NM MAY CONTINUE THROUGH MONDAY. ANOTHER SYSTEM ARRIVES WED
AND THU. THERE ARE CONSIDERABLE UNCERTAINTIES IN THE FCST MODELS FOR
THE SECOND HALF OF THE WEEK...BUT IT APPEARS THAT THERE WILL BE
POTENTIAL FOR GALES AT TIMES.

A LONG PERIOD NW SWELL WILL MAINTAIN SEAS 11 TO 13 FT TODAY. SEAS
WILL SUBSIDE TO AROUND 10 FT SUN AFTERNOON AND DIP BELOW 10 FT THIS
EVENING. LATEST ENP RUN HAS SEAS INCREASING TO NEAR 15 FT LATE NEXT
WEEK AND POSSIBLY NEAR 20 FT NEXT WEEKEND. WANT TO SEE A FEW MORE
RUNS BEFORE GOING THAT HIGH. CAPPED SEAS TO AROUND 15 FT FOR NOW. /MH
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 9 AM PST THIS
     MORNING FOR NORTHERN OREGON CASCADES.

WA...WINTER WEATHER ADVISORY UNTIL 9 AM PST THIS
     MORNING FOR SOUTH WASHINGTON CASCADES.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM PST THIS
     EVENING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     CASCADE HEAD OR OUT 10 NM-COASTAL WATERS FROM
     CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 9 PM PST
     THIS EVENING FOR COASTAL WATERS FROM CAPE SHOALWATER WA
     TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR WINDS UNTIL 4 AM PST MONDAY FOR
     WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM
     10 TO 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
     1 PM THIS AFTERNOON.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM
     7 PM UNTIL MIDNIGHT TONIGHT.

&&

$$

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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