Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 060454
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
845 PM PST FRI FEB  5 2016

.SYNOPSIS...SHOWERS WILL DECREASE TONIGHT AND SATURDAY AS AN UPPER
RIDGE BUILDS ACROSS THE REGION. THIS WILL BEGIN A PERIOD OF DRY WEATHER
WHICH COULD LAST INTO THE MIDDLE OF NEXT WEEK. THIS WEATHER PATTERN
WILL BRING BRISK EAST WINDS THROUGH THE GORGE AND POSSIBLY FOG FOR
AREAS AWAY FROM THE GORGE.

&&

.SHORT TERM...TONIGHT THROUGH MONDAY...THE COLD FRONT MOVED TO THE
COAST BETWEEN 4 AND 5 PM AND INLAND AROUND 6 PM. IT IS NOW IN THE
MOVING INTO THE CASCADES. THERE WAS BRIEF HIGH WINDS ALONG THE BEACHES
AND HEADLANDS IN THE NORTH OREGON AND SOUTH WASHINGTON COAST AS THE
FRONT MADE LANDFALL. RAINFALL AMOUNTS WERE NOT ALL THAT
IMPRESSIVE...AROUND 0.3 TO 0.7 INCH IN THE COAST AND COAST RANGE AND
0.1 TO 0.2 INCH IN THE VALLEY IN THE PAST 6 HOURS ENDING AT 8 PM. RADAR
SHOWS SCATTERED SHOWERS BEHIND THE FRONT. SATELLITE SHOWS LITTLE IN THE
WAY OF COLD TOP CUMULUS MOVING ASHORE SO EXPECT SHOWERS ACTIVITY TO BE
ON THE DECREASE.  WILL LOWER POPS INTO THE CHANCE/SCATTERED CATEGORY
FOR THE REMAINDER OF TONIGHT. HOWEVER THE CASCADES WILL HOLD ON TO THE
STEADIER RAIN FOR THE NEXT COUPLE OF HOURS BEFORE EASING.

SNOW LEVELS WILL FALL BELOW THE PASSES AS THE FRONT MOVES
THROUGH BUT WITH THE PCPN EASING AMOUNTS LOOK BELOW SNOW ADVISORY
CRITERIA...BUT A FEW SPOTS FROM MOUNT HOOD NORTH COULD SEE 2 TO 4
INCHES OVERNIGHT TONIGHT...WITH THE HIGHER AMOUNTS AT SKI AREAS.

AN UPPER RIDGE WILL BEGIN MOVING INTO THE PACIFIC NORTHWEST THE
LATTER PART OF TONIGHT AND ESPECIALLY ON SATURDAY FOR DECREASING
SHOWERS AND IMPROVING WEATHER.

AS THE UPPER RIDGE TAKES HOLD AND MOVES ONSHORE...CLOUD COVER SHOULD
TO BEGIN TO BREAK UP LATER SATURDAY AND ESPECIALLY SATURDAY NIGHT.
THIS WILL LIKELY LEAD TO PLENTY OF FOG AND LOW STRATUS FORMING
SATURDAY NIGHT INTO SUNDAY MORNING DUE TO WET GROUND AND STABILIZING
CONDITIONS. THE FOG AND LOW CLOUDS MAY TAKE A WHILE TO BREAK UP
SUNDAY AFTERNOON. OFFSHORE FLOW INCREASES ON SUNDAY...ESPECIALLY
THROUGH THE GORGE...WHICH SHOULD AID THE CLEARING SUNDAY IN AREAS
AROUND THE COLUMBIA RIVER AND ALONG THE COAST. CLOUDS MAY STILL
LINGER OVER THE SOUTHERN PORTIONS OF THE WILLAMETTE VALLEY AND THE
I-5 CORRIDOR IN SOUTHWEST WASHINGTON...AS THIS LOOKS LIKE A GAP FLOW
EVENT WITH LITTLE OR NO SUPPORT AT 850 MB OR 700 MB. THE PORTLAND AND
VANCOUVER AREAS WILL BE THE MAIN BENEFICIARIES OF THESE EAST WINDS.

LOOK FOR THE EAST WINDS THROUGH THE GORGE TO INCREASE SUNDAY NIGHT AS
THE GRADIENT THROUGH THE GORGE GETS UP TO AT LEAST 7 MB...HOWEVER
THIS STILL LOOKS LIKE A GAP FLOW EVENT. THIS GRADIENT SUPPORTS GUSTS
TO AROUND 50 MPH AT CORBETT AND ROOSTER ROCK...AND MUCH HIGHER AT
CROWN POINT...PERHAPS 60 TO 70 MPH. LOOK FOR LOW STRATUS AND FOG TO
BANK UP AGAINST PARKDALE HOOD RIVER SUNDAY NIGHT AND MONDAY. EXPECT
MORE FOG AND LOW CLOUDS TO DEVELOP IN THE VALLEYS AWAY FROM THE
GORGE...THOUGH THE STRENGTHENING EAST WINDS MAY PREVENT MUCH FOG IN
THE EASTERN SECTIONS OF THE PORTLAND AND VANCOUVER METRO AREAS.

THE WARMING THAT BEGINS IN THE COAST RANGE AND FOOTHILLS ON SUNDAY
DUE TO THE BUILDING UPPER RIDGE WILL INCREASE MONDAY...AND THE PEAK
OF THE INVERSION ON MODEL SOUNDINGS INDICATE THAT 60S ARE POSSIBLE IN
THE MID LEVEL SLOPES OF THE CASCADES AND IN THE COAST RANGE. THE LOW
SUN ANGLE FOR EARLY FEBRUARY AND THE EAST WINDS THROUGH THE GORGE
WILL WORK TO MAINTAIN THE VALLEY INVERSIONS AND COOLER TEMPS IN THE
VALLEYS. TOLLESON /MH
&&

.LONG TERM...MONDAY NIGHT THROUGH FRIDAY...LITTLE CHANGE IN THE
FORECAST THROUGH WEDNESDAY AS A STRONG UPPER LEVEL RIDGE PERSISTS
OVER THE PAC NW. EXPECT WARM AND DRY CONDITIONS UNDER WEAK OFFSHORE
FLOW. LIGHT WINDS WILL ALSO ALLOW PATCHY FOG TO DEVELOP OVERNIGHT
THROUGH EARLY WEDNESDAY OVER MUCH OF THE INTERIOR. THE FOG WILL
LIKELY BURN OFF LATE IN THE MORNING...BUT WOULD NOT BE SURPRISED IF
IT PERSISTS INTO THE AFTERNOON. MODERATE EAST WINDS NEAR THE COLUMBIA
RIVER GORGE WILL HELP LIMIT FOG DEVELOPMENT IN THE NORTH VALLEY.
TEMPS ARE EXPECTED TO CLIMB NEAR 60 EARLY NEXT WEEK...BUT IF THE FOG
LINGERS WE COULD SEE SLIGHTLY COOLER TEMPS. OUR NEXT SHOT AT RAIN
ARRIVES LATE WEDNESDAY AS A WEAK SHORTWAVE BRINGS A STRETCHING FRONT
ACROSS THE PAC NW. THIS WILL HELP OPEN THE DOOR FOR AN ACTIVE WEATHER
PATTERN...WITH WET WEATHER LIKELY CONTINUING LATE NEXT WEEK. /64
&&

.AVIATION...COLD FRONT ON A LINE FROM CENTRAL WASHINGTON AND NEAR
THE NORTH TO FAR NWRN CALIFORNIA AT 04Z. PRIMARILY VFR OVER THE
INLAND LOWLANDS AND A MIX OF CONDITIONS ALONG THE COAST. WLY 850
MB FLOW OF 20-30 KT WILL RESULT IN MVFR OR WORSE CONDITIONS OVER
THE HIGHER TERRAIN WITH FREQUENT OBSCUREMENT THROUGH SAT MORNING.
EXPECTING PRIMARILY VFR OVERNIGHT THROUGH SAT AFTERNOON...EXCEPT
FOR AREAS OF MVFR ALONG THE COAST THROUGH 12Z SAT AND THE
AFOREMENTIONED LOWER CONDITIONS OVER THE HIGHER TERRAIN.

KPDX AND APPROACHES...VFR AT THE TERMINAL AND ALONG APPROACHES AT
04Z. VFR SHOULD PREVAIL THROUGH 06Z SUN. HOWEVER...THERE IS A 20
TO 30 PERCENT THREAT OF MVFR CIGS THROUGH SAT MORNING. WEISHAAR

&&

.MARINE...WIND SPEEDS HAVE DROPPED OFF SINCE LATE AFTERNOON. HAVE
DROPPED THE GALE WARNING AND REPLACED IT WITH SMALL CRAFT
ADVISORIES FOR WIND AND SEAS. STRONGEST WIND WILL CONTINUE TO BE
OVER THE NORTH HALF OF THE NRN WATERS TONIGHT. EXPECT SMALL CRAFT
ADVISORY WIND CONDITIONS TO END OVER THE SRN WATERS AROUND
11Z...BUT MAY BE A LITTLE SOONER THAN THAT. MODELS CONTINUE TO
SHOW A WARM FRONT MOVING THROUGH THE WATERS SAT NIGHT WHICH COULD
RESULT IN 20 TO 25 KT WIND OVER THE OUTER NRN WATERS. OFFSHORE
FLOW PATTERN DEVELOPS SUNDAY AND WILL LAST THROUGH THE MIDDLE OF
NEXT WEEK.

SEAS REMAIN ABOVE 10 FEET THROUGH SAT EVENING. LATEST GUIDANCE
STILL SHOWS SEAS BUILDING JUST ABOVE 10 FT LATE SUN NIGHT OR
MON...THEN FALLING BACK BELOW 10 FT MON NIGHT. WEISHAAR

&&

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

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 10 PM PST
     SATURDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR WINDS UNTIL 3 AM PST SATURDAY FOR
     COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 7 PM
     PST SATURDAY.

&&

$$

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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