Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 301008
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
305 AM PDT SUN AUG 30 2015


.SYNOPSIS...COOLER WITH SHOWERS AROUND REGION THIS AM...BUT SHOWERS
DECREASING THIS AFTERNOON. ANOTHER FRONT WILL PUSH RAIN INTO THE
REGION LATER ON MONDAY...WITH UNSETTLED SHOWERY WEATHER LASTING
THROUGH MUCH OF THIS COMING WEEK.
&&

.SHORT TERM...(TODAY THROUGH TUE)... PATTERN MORE RESEMBLES A LATE
SEPTEMBER OR OCTOBER RATHER LATE AUGUST. A BROAD AREA OF LOW PRES
REMAINS JUST OFFSHORE. COLD FRONT HAS PUSHED ACROSS MUCH OF THE
REGION EARLIER THIS AM...AND IS NOW PUSHING OVER THE CASCADES.
STEADY RAIN GENERALLY EAST OF I5 THIS AM AND WILL CONTINUE TO SHIFT
EASTWARD WITH THE FRONT. LIKE USUAL... A COOLER MORE UNSTABLE AIR
MASS WILL SHIFT INLAND OVER THE REGION. THIS WILL MAINTAIN SHOWERS
TODAY...THOUGH BEST THREAT WILL BE OVER WASHINGTON.

COOLEST AIR...WITH -20C OR COLDER TEMPERATURES ALOFT NEAR 22K FT...
IS JUST OFF THE WASHINGTON COAST. THIS AIR WILL PUSH INTO WASHINGTON
STATE THIS AM...AND OVER FAR NW OREGON. THOUGH TIMING IS NOT MOST
FAVORABLE FOR STRONG CONVECTION...WILL KEEP A SLIGHT CHANCE OF
THUNDERSTORMS FOR AREAS N OF A TILLAMOOK TO SCAPPOOSE TO MT ST HELENS
FOR THIS AM. AS AIR MASS BEGINS STABILIZING LATER TODAY... THE
SHOWERS WILL BE DECREASING...ESPECIALLY OVER OREGON.

DECENT AMOUNT OF CLOUDS OVER REGION TONIGHT... BUT SHOWERS WILL BE
RATHER SPARSE AS WILL BE BETWEEN WEATHER SYSTEMS. THE NEXT FRONT WILL
ARRIVE ON MON...WITH ANOTHER ROUND OF RAIN LATER MON AND MON NIGHT
AND TUE. TEMPERATURES WILL REMAIN RATHER PLEASANT...WITH HIGHS ON THE
COAST IN THE 60S AND INLAND VALLEYS IN LOWER 70S.       QUINTON.

.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY...AN UPPER TROUGH WILL
REMAIN JUST OFF THE PAC NW COAST THROUGH FRI. MODELS SHOW ANOTHER
DECENT PIECE OF ENERGY SWINGING THROUGH AROUND WED OR THU FOR A
BETTER CHANCE OF SHOWERS...BUT THE TIMING VARIES A BIT. THE MODELS
ARE INDICATING IT MAY DRY OUT AND START TO WARM UP SOME NEXT
WEEKEND. TOLLESON
&&


.AVIATION...COLD FRONT HAS MOVED ONSHORE AND IS CURRENTLY RUNNING
ALONG A LINE JUST EAST OF KKLS TO JUST WEST OF KEUG. STRONGER
PORTION OF THE FRONT FROM ABOUT KSLE NORTHWARD IS BRINGING A BRIEF
PERIOD OF LOW END MVFR VSBYS UNDER HEAVY RAIN. THIS REGION WILL
CONTINUE TO MOVE EAST DURING THE NEXT FEW HOURS WITH THE CASCADES
NORTH OF MT JEFFERSON TAKING THE BRUNT.

CONVECTION HAS DEVELOPED OFFSHORE BEHIND THE FRONT AND WILL SEE
THAT AREA MOVE INLAND TODAY. MAY SEE ADDITIONAL PERIODS WHERE MVFR
CIGS/VSBYS DEVELOP BUT HAVE LOW CONFIDENCE IN TIMING AND LOCATION.
WILL AMEND AS CERTAINTY IMPROVES. ALSO HAVE POTENTIAL FOR
SCATTERED CB AND ISOLATED TSRA TO IMPACT A LINE FROM KTMK TO KSPB
TO MT ADAMS THIS MORNING. WILL SEE CONDITIONS STABILIZE SOMEWHAT
AROUND 19Z WITH WEAKER SHOWERS AND LIKELY VFR CONDS PREVAILING FOR
THE AFTERNOON AND EVENING HOURS. OVERNIGHT FOR THE COAST...MVFR
STRATUS SEEMS LIKELY WITH IFR STRATUS/VSBYS POSSIBLE...ESPECIALLY
FOR KONP.

KPDX AND APPROACHES...COLD FRONT CROSSING THE AREA THE NEXT FEW
HOURS. SCT CB AND ISOLD TSRA POSSIBLE MAINLY AFFECTING NORTHERN
AND WESTERN APPROACHES THROUGH 19Z. CONDITIONS IMPROVE THIS
AFTERNOON AND ATMOSPHERE STABILIZES. EXPECT APPROACH CIGS TO
REMAIN AOA FL040 AFT 19Z. /JBONK
&&

.MARINE...WINDS HAVE EASED ACROSS THE INNER WATERS BEHIND THE COLD
FRONTAL PASSAGE EARLIER. FRESH SWELL IS KEEPING SQUARE SEAS ACROSS
MOST OF THE WORKING BUOYS AND EXPECT ANOTHER REINFORCING 7 TO 9 FT
SWELL BY THIS AFTERNOON SO HAVE EXTENDED THE ADVISORY FOR SEAS
COVERING ALL WATERS THROUGH EARLY THIS EVENING.

A COUPLE WEAK SYSTEMS WILL BRUSH THE NORTHERN WATERS FIRST THIS
AFTERNOON AND EVENING THEN AGAIN FROM AROUND DAYBREAK MONDAY
THROUGH THE EARLY EVENING WITH GUSTS AROUND 25 KT. AS SUCH HAVE
ISSUED ANOTHER ADVISORY FOR WINDS.

SEAS WILL REMAIN 7 TO 10 FEET FOR THE UPCOMING WEEK AS THE
UNSETTLED PATTERN REMAINS OVER THE REGION. IT APPEARS LONGER
PERIOD DISTANT SWELL WILL DOMINATE AFTER TODAY, BUT MAY GET
ADDITIONAL SETS OF SQUARE SEAS/FRESH SWELL AT TIMES. /JBONK
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 9 AM PDT THIS MORNING FOR
     WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR FROM 10
     TO 60 NM-WATERS FROM CASCADE HEAD TO FLORENCE OR FROM 10 TO
     60 NM.

     SMALL CRAFT ADVISORY FOR WINDS FROM 7 PM THIS EVENING TO 6 PM
     PDT MONDAY FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     CASCADE HEAD OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 8 PM PDT THIS
     EVENING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE
     OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 9 AM
TODAY...AND 3 PM TO 10 PM TODAY.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 3 PM THIS
AFTERNOON TO
     10 PM PDT THIS EVENING.

&&



$$

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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