Area Forecast Discussion
Issued by NWS Portland, OR

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752
FXUS66 KPQR 062239
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
239 PM PST SAT FEB  6 2016

.SYNOPSIS...AN INITIALLY MODEST UPPER RIDGE WAS CONTINUING TO SPREAD
INTO THE PACIFIC NORTHWEST TODAY...WITH A FAIR AMOUNT OF CLOUD COVER
OVER SOUTHWEST WASHINGTON AND NORTHWEST OREGON. THIS WILL LIFT NORTH
SUNDAY AS THE UPPER RIDGE BUILDS AND AS THE ASSOCIATED WARM FRONT
THAT IS MOSTLY OFFSHORE ALSO LIFTS NORTH. AS THE UPPER RIDGE
INTENSIFIES...OFFSHORE FLOW WILL START TO DEVELOP ESPECIALLY SUNDAY
NIGHT AND CONTINUE THROUGH AT LEAST TUESDAY. THE FIRST SYSTEM TRYING
TO BREAK DOWN THE RIDGE WILL WEAKEN AS IT REACHES THE COAST
WEDNESDAY...THEN SUBSEQUENT SYSTEMS WILL HAVE A BETTER CHANCE OF
BRINGING PRECIPITATION BACK TO SOUTHWEST WASHINGTON AND NORTHWEST
OREGON AT TIMES DURING THE LATTER PART OF NEXT WEEK AND NEXT WEEKEND.
&&

.SHORT TERM...TONIGHT THROUGH SUNDAY...A MODEST UPPER RIDGE HAD
SPREAD OVER THE PACIFIC NORTHWEST TODAY...BUT A FAIR AMOUNT OF CLOUD
COVER WAS SPREADING OVER THE RIDGE INTO THE PACIFIC NORTHWEST AHEAD
OF THE NEXT SYSTEM THAT IS WAY OFFSHORE. THERE IS A WARM FRONT WITH
THIS STREAM OF MOISTURE...BUT IT APPEARS TO BE MAINLY OFFSHORE. THE
MODELS INDICATE WE WILL CONTINUE TO HAVE A FAIR AMOUNT OF CLOUDS
TONIGHT INTO SUNDAY MORNING BEFORE THIS MOISTURE AND WARM FRONT LIFTS
NORTH AND THE CLOUDS BREAK UP SUNDAY AFTERNOON. AS A RESULT... THINK
THE FOG AND LOW CLOUDS WILL BE LESS EXTENSIVE TONIGHT AND SUNDAY
MORNING THAN PREVIOUSLY THOUGHT...WITH THE BEST CHANCE OF MUCH IN THE
SOUTH NEAR EUGENE. HAVE BOOSTED MIN TEMPS A BIT TONIGHT AS A RESULT.
THE MODELS ALSO SUGGEST AT SOME LIGHT RAIN CATCHING THE COASTAL
WATERS AND SOME SPRINKLES POSSIBLE NEAR THE COAST AND LOCALLY INLAND
TONIGHT AND EARLY SUNDAY AS WELL.

AS THE UPPER RIDGE BUILDS AND SHARPENS ALONG THE COAST SUNDAY... THE
CLOUDS SHOULD BREAK UP SUNDAY AFTERNOON ACROSS THE AREA. HOWEVER THE
MODEL CHANGES WE ARE SEEING INDICATE THAT THE EAST WIND WILL BE
SLOWER IN DEVELOPING ON SUNDAY...AND WITH LESS FOG EXPECTED...HAVE
RAISED MAX TEMPS A BIT FOR SUNDAY.

THE MODELS SHOW THE EAST WINDS DEVELOPING THROUGH THE GORGE IN
EARNEST SUNDAY NIGHT...WITH GRADIENTS THROUGH THE GORGE OF AROUND 7
MB. THIS WOULD SUPPORT GUSTS TO AROUND 50 MPH AT CORBETT AND ROOSTER
ROCK...AND HIGHER...PERHAPS 60 TO 70 MPH AT CROWN POINT. WE SHOULD
SEE FOG AND LOW CLOUDS DEVELOP IN MOST OF THE INLAND AREAS AWAY FROM
THE GORGE SUNDAY NIGHT AND MONDAY UNDER MOSTLY CLEAR SKIES AND GOOD
RADIATIONAL CONDITIONS...WHICH WILL BE SLOW TO BREAK OUT IN THE LATE
AFTERNOONS. THIS WILL SUPPRESS MAX TEMPS BEGINNING MONDAY IN THOSE
AREAS... SUCH AS AROUND EUGENE AND NORTH OF KELSO.

AS THE GRADIENT INCREASES THROUGH THE GORGE...LOOK FOR PERSISTENT LOW
CLOUDS AND LOCAL FOG TO DEVELOP NEAR PARKDALE AND HOOD RIVER SUNDAY
NIGHT AND BEYOND.

THE EAST WIND NEAR PORTLAND WILL HELP THAT AREA WARM UP INTO THE 50S
MONDAY...BUT THAT WILL BE NOT AS WARM AS THE COAST...THE
FOOTHILLS...AND COAST RANGE WHERE SOME 60S ARE POSSIBLE ABOVE THE
VALLEY INVERSIONS.

THERE IS NO EAST WIND SUPPORT AT 850 MB AND 700 MB WITH THIS EAST
WIND EVENT...AND IN FACT THE WINDS ARE LIGHT SOUTHWESTERLY AT THOSE
LEVELS. THIS SUPPORTS THE INVERSION IDEA AND A CRITICAL LEVEL ABOVE
THE GAP FLOW. THUS THIS SHOULD BE MAINLY A GAP FLOW EVENT. EXPECT
AREAS OF NIGHT AND MORNING FOG AND LOW CLOUDS IN THE VALLEYS AWAY
FROM THE COLUMBIA RIVER THAT COULD PERSIST A WHILE IN THE AFTERNOONS
MONDAY AND TUESDAY...WITH MUCH LESS NEAR PORTLAND AND VANCOUVER
ESPECIALLY IN THE EAST COUNTY AREAS.

WE SEE A NEAR REPEAT ON TUESDAY OF THE WEATHER FROM MONDAY. TOLLESON

.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY...ONE MORE DRY OFFSHORE
FLOW DAY TUESDAY WITH FOG AND LOW CLOUDS ESPECIALLY AWAY FROM THE
COLUMBIA GORGE. THE MODELS ARE SAYING THE FIRST SYSTEM TRYING TO
BREAK DOWN THE RIDGE WILL WEAKEN A LOT AS IT ARRIVES AT THE COAST
WEDNESDAY. THIS WILL BE FOLLOWED BY A SERIES OF SYSTEMS THE REMAINDER
OF NEXT WEEK AND INTO NEXT WEEKEND THAT WILL BRING AN INCREASING
CHANCE OF RAIN AT TIMES TO SOUTHWEST WASHINGTON AND NORTHWEST
OREGON...THOUGH SOME DRY AND MILD PERIODS APPEAR INTERSPERSED.
TOLLESON
&&

.AVIATION...MID AND UPPER LEVEL HIGH CLOUDS WILL CONTINUE TO STREAM
ACROSS THE REGION OVERNIGHT AND EARLY SUNDAY...LIKELY THICKENING A
BIT BETWEEN 06Z AND 18Z SUNDAY. IT APPEARS THESE CLOUDS MAY PREVENT
WIDESPREAD FOG AND/OR LOW CLOUDS FROM DEVELOPING...BUT CANNOT RULE
SOME LIFR/IFR CONDITIONS STILL DEVELOPING AT SEVERAL OF OUR TAF
SITES. HOWEVER...CONFIDENCE IN THE DETAILS SUCH TIMING AND WHICH
SITES WILL EXPERIENCE THE MOST SEVERE FLIGHT RESTRICTIONS REMAINS
LOW.

KPDX AND APPROACHES...A WARM FRONT LIFTING NORTHEASTWARD OFFSHORE
WILL BRING PERIODS OF MID AND UPPER LEVEL CLOUDS OVERNIGHT...WHICH
MAY LIMIT FOG AND/OR LOW CLOUD DEVELOPMENT. HOWEVER...THERE MAY BE
ENOUGH BREAKS IN THE CLOUD COVER TO ALLOW AT LEAST SOME FLIGHT
RESTRICTIONS TO DEVELOP...BUT WHETHER THEY WILL BE BRIEF OR PROLONGED
AND IN THE MVFR OR IFR CATEGORY IS RATHER UNCERTAIN AT THIS POINT.
/NEUMAN
&&

.MARINE...A WARM FRONT WILL BRING INCREASING WINDS AGAIN LATE TONIGHT
AND FOR AT LEAST THE FIRST HALF OF SUNDAY ACROSS MAINLY THE OUTER
NORTHERN WATERS. SOUTHERLY WIND GUSTS WILL LIKELY ONLY PEAK AROUND 25
KT THOUGH. AN OFFSHORE FLOW PATTERN WILL LIKELY DEVELOP LATER SUNDAY
AND MONDAY...AND LIKELY LINGER INTO THE MIDDLE OF NEXT WEEK. ANOTHER
WARM FRONT IS MODELED TO BRING INCREASING SOUTHERLY WINDS AGAIN
TUESDAY NIGHT INTO WEDNESDAY.

SEAS SHOULD DROP BELOW 10 FT THIS EVENING. SEAS LOOK TO CLIMB BACK
ABOVE 10 FT FOR MONDAY AND MONDAY NIGHT BEFORE RELAXING A BIT TOWARDS
THE MIDDLE OF NEXT WEEK. A SERIES OF LARGE AND LONGER PERIOD WESTERLY
SWELLS LOOK TO BRING SEAS WELL INTO THE TEENS LATE NEXT WEEK. /NEUMAN
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS FROM 1 AM TO 3 PM PST SUNDAY
     FOR WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM
     10 TO 60 NM.

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

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

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM
     1 AM TO 6 AM PST 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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