Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 052240 AAA
AFDPQR

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
240 PM PST FRI FEB  5 2016

ADDED NEW MARINE AND AVIATION SECTIONS

.SYNOPSIS...A STRONG PACIFIC OCCLUDED FRONT JUST OFF THE COAST THIS
AFTERNOON WILL SPREAD RAIN ONSHORE INTO SOUTHWEST WASHINGTON AND
NORTHWEST OREGON THIS AFTERNOON...MOVE ONTO THE COAST AROUND 4 OR 5
PM...AND THROUGH THE INLAND AREAS OF SOUTHWEST WASHINGTON AND
NORTHWEST OREGON THIS EVENING. THIS FRONT WILL PRODUCE VERY WINDY
CONDITIONS AT THE COAST THIS AFTERNOON AND BREEZY CONDITIONS INLAND
LATER THIS AFTERNOON AND EVENING. AN UPPER RIDGE WILL BEGIN BUILDING
SATURDAY FOR DRYING...WHICH COULD LAST INTO THE MIDDLE OF NEXT
WEEK...WITH EAST WINDS NEAR THE GORGE AND POSSIBLY FOG AWAY FROM THE
GORGE.
&&

.SHORT TERM...TONIGHT THROUGH MONDAY...THE WELL ADVERTISED STRONG
PACIFIC OCCLUDED FRONT WAS APPROACHING THE COAST THIS AFTERNOON. A
WIND SHIFT OCCURRED AT BUOY 5 BETWEEN 6 AND 7 AM AND AT BUOY 2
BETWEEN 8 AND 9 AM THIS MORNING. THE FRONT IS APPROACHING BUOY 89 AS
WINDS HAVE INCREASED INTO THE LOW 40 KT RANGE SO FAR. THE LOW LEVEL
JET AHEAD OF THE FRONT STILL SUPPORTS STRONG GALES AND POSSIBLY A FEW
LOW END STORM FORCE GUSTS OVER THE COASTAL WATERS...WITH HIGH WINDS
ALONG THE COAST ESPECIALLY AT THE BEACHES AND HEADLANDS AND
MARGINALLY IN THE COASTAL COMMUNITIES.

850 MB WINDS STILL LOOK TO BE 65 TO 75 KT AS THE FRONT MOVES ONSHORE
ALONG THE COAST AROUND 4 OR 5 PM THIS AFTERNOON...AND THIS SUPPORTS
GUSTS TO AROUND 70 MPH AT THE BEACHES AND HEADLANDS. WILL STAY BELOW
HIGH WIND IN THE COAST RANGE...BUT THE HIGHEST ELEVATIONS AND TOWERS
IN THE COAST RANGE SUCH AS MARYS PEAK...MT HEBO AND POSSIBLY
ABERNATHY MTN RAWS MIGHT RECORD A FEW GUSTS ABOVE 60 MPH. WINDS IN
THE INLAND VALLEYS WILL SWITCH FROM EAST OR SOUTHEAST TO SOUTH WITH
GUSTS 25 TO 35 MPH THIS EVENING.

SNOW LEVELS WILL INITIALLY BE WAY ABOVE THE PASSES TODAY...THEN
RATHER DRAMATICALLY FALL BELOW THE PASSES AS THE FRONT MOVES
THROUGH THIS EVENING. AMOUNTS LOOK BELOW SNOW ADVISORY CRITERIA...
BUT A FEW SPOTS FROM MOUNT HOOD NORTH COULD SEE 3 TO 6 INCHES
OVERNIGHT TONIGHT...WITH THE HIGHER AMOUNTS AT SKI LEVEL TYPE
ELEVATIONS.

THE WIND SHIFT WITH THE FRONT IS NOT ON THE BACK SIDE OF THE
FRONT...SO IT WILL LIKELY RAIN FOR A COUPLE OF HOURS AFTER THE WIND
SWITCH BEFORE THE TYPICAL CHANGE OVER TO SHOWERS.

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
&&

.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...EXPECT THE CURRENT VFR CONDITIONS FOUND AT MOST TAF
SITES IN NORTHWEST OREGON AND SOUTHWEST WASHINGTON TO DETERIORATE
LATE THIS AFTERNOON AND EARLY THIS EVENING AS A COLD FRONT SPREADS
STEADIER RAIN INTO THE REGION. CIGS SHOULD GENERALLY LOWER INTO MVFR
FOR A SEVERAL HOUR PERIOD BEFORE RAIN TURNS MORE SHOWERY AND
CONDITIONS TURN BACK TO PREDOMINANTLY VFR WITH ONLY OCCASIONAL MVFR
CONDITIONS UNDER OR NEAR HEAVIER SHOWERS BETWEEN 06Z AND 18Z
SATURDAY. THERE IS A CHANCE THAT A FEW LOCATIONS...PARTICULARLY
KHIO...MAY STABILIZE ENOUGH TO ALLOW LIFR/IFR CONDITIONS TO DEVELOP
AROUND 12Z SATURDAY.

KPDX AND APPROACHES...EXPECT VFR CONDITIONS TO CONTINUE THROUGH
02Z THIS EVENING. RAIN ACCOMPANYING A COLD FRONT IS LIKELY TO
DEVELOP AROUND 00Z SATURDAY...WITH CIGS LIKELY DROPPING TO MVFR
AROUND 02Z SATURDAY. POST FRONTAL SHOWERS SHOULD BRING A MIX OF
VFR AND MVFR CONDITIONS...ALBEIT MAINLY VFR...BETWEEN 06Z AND 18Z
SATURDAY. /NEUMAN
&&

.MARINE...A COLD FRONT MOVING EASTWARD ACROSS THE COASTAL WATERS
THIS AFTERNOON IS CURRENTLY BRINGING WIDESPREAD GALE FORCE WIND
GUSTS OF 40 TO 45 KT TO THE WATERS WITH SEAS HOVERING BETWEEN 17
AND 23 FT. WINDS MAY NUDGE UP ANOTHER 5 KT OR SO AND SEAS ANOTHER
FOOT OR TWO...BUT EXPECT WINDS AND SEAS TO BEGIN TO RELAX ONCE THE
COLD FRONT PUSHES THROUGH BETWEEN 4 PM AND 6 PM THIS EVENING.
WINDS WILL DROP OFF BEHIND THE FRONT WITH GUSTS OF 25 TO 35 KT
FOR A COUPLE HOURS BEFORE SUBSIDING FURTHER OVERNIGHT. SEAS SHOULD
DROP SOLIDLY INTO THE MID TEENS AROUND MIDNIGHT AND DROP BELOW 10
FT SATURDAY EVENING.

HIGH PRESSURE SHIFTING OVER THE REGION FOR THIS WEEKEND WILL
LIKELY KEEP SEAS AND WINDS BELOW SMALL CRAFT CRITERIA FOR AT LEAST
SUNDAY. HOWEVER...A COUPLE SWELLS AROUND 10 FT MAY REQUIRE SMALL
CRAFT ADVISORIES FOR HAZARDOUS SEAS MONDAY AND AGAIN LATER IN THE
WEEK. A MORE ACTIVE WEATHER PATTERN LOOKS TO RETURN MID TO LATE
NEXT WEEK. /NEUMAN
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING UNTIL 6 PM PST THIS EVENING FOR CENTRAL
     OREGON COAST-NORTH OREGON COAST.

WA...HIGH WIND WARNING UNTIL 6 PM PST THIS EVENING FOR SOUTH
     WASHINGTON COAST.

PZ...GALE WARNING UNTIL 10 PM PST THIS EVENING FOR COASTAL WATERS
     FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
     3 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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