Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 042143
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
244 PM PDT WED MAY  4 2016

.SYNOPSIS...SHOWERY PATTERN CONTINUES THROUGH THURSDAY EVENING AS
UPPER LOW PASSES TO OUR SOUTH. THEN HIGH PRES BUILDS INTO THE REGION
WITH WARMER AND DRY WEATHER FOR FRI INTO MOST OF NEXT WEEK. WEAK
FRONT WILL PASS OVER REGION SUNDAY...BUT NO RAIN AS IT JUST INCREASES
ONSHORE FLOW WITH MORE LATE NIGHT/AM LOW CLOUDS.
&&

.SHORT TERM...(TONIGHT THROUGH SAT)...
SEEMS LIKE A BROKEN RECORD...BUT NOT A LOT OF CHANGE OVER THE REGION.
AN UPPER TROUGH CONTINUES TO SLOWLY MOVE EASTWARD OVER THE
REGION...WITH MAIN UPPER LOW IN THE BASE OF THE TROUGH OFF THE CALIF
COAST. MILD AND SOMEWHAT UNSTABLE SOUTHERLY FLOW REMAINS OVER MUCH OF
THE REGION. THANK TO AFTERNOON HEATING TO BOOST INSTABILITY A BIT DO
HAVE SHOWERS OVER THE REGION EXTENDING S INTO NORTHERN CALIF. THESE
SHOWERS WILL CONTINUE TO DRIFT NORTHWARD...WITH INCREASED FREQUENCY
AS MOVE SOUTH TOWARDS SW OREGON. NOT A LOT OF THREAT OF THUNDERSTORMS
ON THE WESTSIDE. DO HAVE ISOLATED THUNDERSTORMS POPPING UP THIS
AFTERNOON CENTRAL OREGON AND UP NEXT TO THE CASCADES CREST. FOR MOST
PART...THUNDERSTORM THREAT STAYS EAST OF THE CREST BUT WILL KEEP
ISOLATED THUNDERSTORMS THROUGH THIS EVENING ON THE CASCADES AND HOOD
RIVER VALLEY SOUTHWARD. WILL MAINTAIN SLIGHT CHANCE OF THUNDERSTORMS
FOR THE S WASHINGTON CASCADES AND ALL CASCADES FOOTHILLS.

THE RELATIVELY COOL UPPER TROUGH ASSOCIATED WITH THE DYING FRONTAL
SYSTEM IS ALSO WEAKENING...AS MOST OF THE JET ENERGY IN THE NE PAC
GOES TOWARD DEVELOPING A CUTOFF LOW NEAR THE CALIFORNIA COAST. EXPECT
SHOWERS TO DECREASE A BIT THURSDAY...PERHAPS BECOMING MORE CONFINED
TO THE CASCADES. MEANWHILE UPPER LEVEL RIDGING WILL STRENGTHEN OVER
WASHINGTON AND WESTERN CANADA...CREATING A WEAK REX BLOCK TYPE OF A
PATTERN WITH UPPER RIDGING TO THE N AND AN UPPER LOW TO THE S.
THIS WILL EVENTUALLY BRING ANOTHER BOUT OF WARM AND DRY WEATHER TO
THE REGION...STARTING FRI.  AFTER SPOTTY AM LOW CLOUDS ON SAT
AM...WILL SEE PLENTY OF SUNSHINE WITH TEMPERATURES CLIMBING INTO
LOWER 80S.                      ROCKEY.

.LONG TERM...(SAT NIGHT THROUGH WED)... HIGH PRES WILL BUILD OVER THE
REGION...WITH MILD TEMPERATURES AND STABLE NW FLOW ALOFT. THIS WILL
KEEP A MORE JUNE LIKE PATTERN...WITH LATE NIGHT/AM CLOUDS THEN MOSTLY
CLEAR SKIES. WEAK FRONT WILL PASS ACROSS THE REGION SUN...BUT LOOKS
DRY. MAIN EFFECT WILL BE INCREASED ONSHORE FLOW. WILL COOL SUN AND
MON BACK TO THE MID TO UPPER 60S...WITH MORNING CLOUDS GIVING WAY TO
PARTLY TO MOSTLY CLEAR SKIES. COASTAL AREAS MAY NOT SEE MUCH CLEARING
UNTIL LATER IN THE AFTERNOONS. AFTERWARDS...WILL SEE WEAKENING
ONSHORE FLOW WITH WARM AND DRY WEATHER.           ROCKEY.
&&


.AVIATION...INCONSISTENT CIGS THIS AFTERNOON WITH CIGS BOUNCING
BETWEEN MVFR AND VFR AS SCATTERED SHOWERS MOVE NORTHWARD ACROSS
NORTHWEST OREGON AND SOUTHWEST WASHINGTON. THESE SCATTERED
SHOWERS WILL BECOME MORE NUMEROUS THROUGH THE REMAINDER OF THE
AFTERNOON AND INTO THE EVENING. EXPECT THE INCONSISTENT CIGS TO
CONTINUE THROUGH ~06Z BEFORE ~2KFT CLOUD DECK BUILDS INTO THE
VALLEY OVERNIGHT. MOST HIGH RESOLUTION GUIDANCE KEEPS THIS CLOUD
DECK OVERCAST TO BROKEN THROUGH MID DAY THURSDAY.

KPDX AND APPROACHES...VFR AS OF 21Z...BUT EXPECT PERIODS OF LOWER
2000 TO 2500 FOOT MVFR CIGS THROUGH 23Z. INCREASING THREAT OF
-SHRA THIS AFTERNOON AND INTO THIS EVENING. EXPECT LOWER MVFR CIGS
TO DEVELOP AFTER 07Z.                             BENTLEY
&&

.MARINE...SMALL CRAFT ADVISORY FOR WIND REMAINS IN PLACE THROUGH
12Z THU FOR THE NEARSHORE WATERS AND THROUGH 18Z FOR THE OFFSHORE
AREAS. SMALL CRAFT ADVISORY FOR WINDS MAY NEED TO BE EXTENDED IN
TIME FOR NEARSHORE WATERS...BUT DID NOT EXTEND AT THIS TIME DUE TO
INDICATIONS OF A WEAKENING PRESSURE GRADIENT ALONG THE SHORE
DURING THE DAY THURSDAY. WINDS IN THE NEARSHORE ZONES WILL REMAIN
BORDERLINE SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT AND FRIDAY
BEFORE INCREASING AGAIN FRIDAY NIGHT.

TOTAL WAVE HEIGHTS HAVE INCREASED TO THE 7 TO 10 FT EARLY THIS
AFTERNOON AND SHOULD REMAIN THERE INTO THE EVENING AND OVERNIGHT.
WITH PREDOMINATELY WIND DOMINATED SEAS...7-8 SECOND PERIODS HAVE
WILL KEEP SEAS STEEP AND CHOPPY...THUS A SMALL CRAFT ADVISORY FOR
HAZARDOUS SEAS REMAINS IN EFFECT THROUGH 18Z THURSDAY. BENTLEY
&&


.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 AM THURSDAY FOR
         OUTER COASTAL WATERS...OR FROM 10 TO 60 NM OFFSHORE
         FROM CAPE SHOALWATER TO FLORENCE.

     SMALL CRAFT ADVISORY FOR WINDS THROUGH TONIGHT FOR THE
         INNER COASTAL WATERS...OR FROM SHORE OUT 10 NM FROM
         CAPE SHOALWATER TO FLORENCE.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 AM THU ON
        ALL COASTAL WATERS.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 PM
        TODAY...AND AGAIN 2 AM TO 6 AM THU.

&&

$$

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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