Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 260409
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
907 PM PDT SAT OCT 25 2014

.SYNOPSIS...GUSTY WINDS WILL EASE TONIGHT. AN UPPER LEVEL TROUGH WILL
MAINTAIN SHOWERS TONIGHT AND SUNDAY...WITH SNOW LEVELS LOWERING TO
AROUND 4500 FEET. THERE MAY BE A BRIEF BREAK IN RAIN SUNDAY NIGHT AND
MONDAY BEFORE A MOIST FRONT MOVES ACROSS THE AREA MONDAY NIGHT AND
TUESDAY. ANOTHER FRONT IS EXPECTED LATE IN THE WEEK.

&&

.UPDATE...THE SURFACE LOW RESPONSIBLE FOR THE DAMAGING WINDS THIS
AFTERNOON AND EVENING HAS MOVED INLAND AND IS CURRENTLY OVER NW
WASHINGTON. THE SURFACE PRESSURE GRADIENT IS DECREASING AND WINDS ARE
EASING. THE MEDFORD TO ASTORIA SURFACE PRESSURE GRADIENT PEAKED AT
17.5 MB AROUND 4 PM...AND IS CURRENTLY AROUND 10 MB. THERE WERE
NUMEROUS REPORTS OF WIND DAMAGE WHICH CAN BE LOCATED AT PDXLSRPQR OR
FROM A LINK ON THE TOP OF THE NWS PORTLAND WEB PAGE AT
WWW.WEATHER.GOV/PORTLAND. GUSTY WINDS WILL GRADUALLY DIMINISH
TONIGHT.

AS FAR AS RAINFALL...THE OREGON COAST RANGE HAS HAD THE HIGHEST
AMOUNT OF RAIN WHERE STATIONS REPORTED 0.6 TO 1.3 INCHES IN THE PAST
12 HOURS. THE WILLAMETTE VALLEY MEASURED BETWEEN 0.1 AND 0.2 INCH AND
THE CASCADES BETWEEN 0.3 AND 0.5 INCH. RAIN IS STILL STEADY OVER THE
CASCADES...AND EXPECT THOSE TOTALS TO CONTINUE TO RISE
TONIGHT...OTHERWISE THE RAIN HAS TURNED TO SHOWERS AS AN UPPER TROUGH
OVER THE NE PACIFIC APPROACHES THE COAST.

SNOW LEVELS ARE CURRENTLY AROUND 6500 FEET AND WILL LOWER TONIGHT
DOWN TO AROUND 4500 FEET SUNDAY MORNING. SHOWERS WILL PERSIST TONIGHT
AND SUNDAY. ELEVATIONS BETWEEN 4500 AND 6000 FEET MAY SEE LOCAL SNOW
ACCUMULATIONS OF 1 TO 4 INCHES AND ELEVATIONS ABOVE 6000 FEET MAY
MEASURE 3 TO 8 INCHES. THE SHOWERS WILL DECREASE SUNDAY
EVENING...WITH MOST AREAS DRY SUNDAY NIGHT AND MONDAY MORNING.

THE ATTENTION THEN TURNS TO THE NEXT FORECAST CHALLENGE...A MOIST
FRONT MONDAY NIGHT AND TUESDAY...WITH POSSIBLE ENERGY AND MOISTURE
FROM HURRICANE ANA. SATELLITE IMAGERY SHOWS THE REMNANTS OF HURRICANE
ANA CURRENTLY NEAR 37N 158W AND MOVING TOWARDS THE NE PACIFIC. MODELS
ARE INITIALIZING FAIRLY WELL WITH ITS TRACK SO FAR...AND FORECAST IT
TO COMBINE ENERGIES WITH AN UPPER TROUGH CURRENTLY OVER THE ALEUTIAN
ISLANDS...AND FORM AN UPPER LOW OFF SHORE THE BC COAST MONDAY.

MODELS HISTORICALLY HANDLE THESE TYPE OF SYSTEMS POORLY...ADDING TO
THE FORECAST CHALLENGE. HOWEVER THE VARYING MODELS ARE IN A FAIR
AGREEMENT THAT A MOIST...BUT FAIRLY QUICK MOVING FRONT ASSOCIATED
WITH THIS SYSTEM  WILL MOVE ACROSS WASHINGTON AND OREGON MONDAY NIGHT
AND TUESDAY. SNOW LEVELS WILL RISE AHEAD OF IT...AND DO NOT
ANTICIPATE WINTER WEATHER. THE BEACHES MAY SEE SOME GUSTY WINDS WITH
THE FRONT PASSAGE TUE MORNING. TJ

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...MONDAY NIGHT
THROUGH FRIDAY...UPPER-LEVEL TROUGH MOVES TOWARD THE PACIFIC
NORTHWEST LATE THIS WEEK.  SHORTWAVES IN THE SOUTHWESTERLY FLOW ALOFT
WILL CONTINUE TO BRING THE CHANCE FOR RAIN ACROSS OUR AREA THROUGH
FRIDAY. MODELS ARE IN AGREEMENT THAT THERE WILL BE A COUPLE WEAK
FRONTS...ONE WHICH MOVES ONSHORE TUESDAY AND A SECOND THAT MOVES
ONSHORE LATE THIS WEEK. THESE WILL BRING THE BEST CHANCE FOR MODERATE
RAIN SHOWERS...WITH MAINLY LIGHT RAIN EXPECTED INTERMITTENTLY BEHIND
THE FIRST FRONT ON TUESDAY AHEAD OF THE SECOND FRONT EXPECTED TO
ARRIVE AROUND FRIDAY. -MCCOY

&&

.AVIATION...A 990 MB LOW PRES HAS PUSHED INLAND OVER WESTERN
WASHINGTON THIS EVENING...ALLOWING WIDESPREAD VFR CONDITIONS TO
PREVAIL. S TO SW WINDS 10 TO 15 KT CAN BE EXPECTED TO CONTINUE
THROUGH 08-10Z BEFORE WEAKENING. A FEW GUSTS NEAR 25 KT STILL
POSSIBLE ALONG THE NORTH OREGON COAST THROUGH MIDNIGHT. MVFR CIGS
TO DEVELOP UNDER SHOWERS THROUGH THE NIGHT.

KPDX AND APPROACHES...MOSTLY VFR NEXT 24 HRS...EXCEPT FOR MARGINAL
MVFR CIGS AROUND 3000-3500 FT POSSIBLE AFTER 10Z SUN. SOUTH WINDS
CONTINUE AROUND 10 TO 15 KT...AND WILL GRADUALLY RELAX AFTER
MIDNIGHT. /27

&&

.MARINE...LOW PRES HAS NOW MOVED ONSHORE INTO NORTHWESTERN
WASHINGTON THIS EVENING. WINDS AND SEAS OVER THE NORTHERN COASTAL
WATERS WILL REMAIN ELEVATED THROUGH MIDNIGHT...BEFORE GRADUALLY
SUBSIDING THROUGH SUNDAY. A GALE WARNING REMAINS IN EFFECT FOR THE
NORTHERN WATERS THROUGH EARLY SUNDAY MORNING. SEAS REMAIN
ELEVATED OVER THE CENTRAL OR WATERS...BUT WINDS HAVE DROPPED BELOW
GALE WARNING CRITERIA...SO HAVE ISSUED A HIGH END SMALL CRAFT
ADVISORY FOR WINDS THROUGH MIDDAY SUNDAY. OVERALL...SEAS LIKELY
TO DROP BACK TO AROUND 15 FT AROUND MIDNIGHT TONIGHT...AND DOWN A
BIT FURTHER FOR SUN. /27

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WARNING UNTIL 2 AM PDT SUNDAY FOR COASTAL WATERS FROM
     CAPE SHOALWATER WA TO CASCADE HEAD OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR WINDS UNTIL NOON PDT SUNDAY FOR
     COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60
     NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
     NOON PDT SUNDAY.
&&


$$

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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