Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 020333
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
833 PM PDT WED JUL 1 2015

.SYNOPSIS...A RIDGE OF HIGH PRES OVER THE WESTERN STATES WILL
MAINTAIN ITS GRIP ON THE REGION THROUGH THE WEEKEND. THIS WILL KEEP
THE HEAT WAVE GOING WITH PLENTY OF SUNSHINE. THE NEXT BEST CHANCE
FOR SOME COOLING COMES EARLY NEXT WEEK AS A STRONG RIDGE BUILDS
OFFSHORE AND WEAKENS INLAND.

&&

.UPDATE...WITH LAX WEST-EAST GRADIENTS...DO NOT EXPECT MUCH MARINE
PUSH TONIGHT. MOST OF THE COAST IS CURRENTLY CLEAR ALTHOUGH IT LOOKS
LIKE STRATUS HAS DEVELOPED ALONG THE IMMEDIATE COAST AS FAR NORTH AS
LINCOLN COUNTY. EXPECT THAT STRATUS TO MOVE UP THE COAST AND
EVENTUALLY INLAND TO AROUND KELSO BY MORNING. BUT DO NOT EXPECT
MORNING STRATUS IN THE PDX METRO OR CLARK COUNTY. NO UPDATES NEEDED
TO THE FORECAST. BOWEN

.SHORT TERM (PREVIOUS DISCUSSION)...A STRONG RIDGE OF HIGH PRES THAT
EXTENDED FROM THE SW STATES TO OFF THE OREGON COAST WILL REMAIN INTO
THE WEEKEND. THIS WILL KEEP A RATHER STAGNANT PATTERN IN PLACE
THROUGH SAT...LIKELY RESULTING IN ONLY MINOR CHANGES TO TEMPERATURES.
WITH A WEAK ONSHORE FLOW AND SATELLITE SHOWING MOST OF THE MARINE
CLOUDS GONE THIS AFTERNOON...EXPECT ONLY A LIMITED AMOUNT OF CLOUDS
AND FOG TO REFORM ALONG THE COAST LATE TONIGHT AND EARLY THU MORNING.

MODELS SHOW A COUPLE OF SHORTWAVES MOVING ACROSS THE TOP OF THE
RIDGE...BRUSHING ACROSS WA THU AFTERNOON AND AGAIN SAT. THE AFFECTS
OF THE SHORTWAVES THOUGH APPEAR MINIMAL...PERHAPS A LITTLE STRONGER
ONSHORE FLOW FOR FRI AND SAT AS SUGGESTED BY THE GFS..BUT WITH H8
TEMPS STILL IN THE RANGE OF 20 TO 23 DEG C EACH DAY. A STRENGTHENED
ONSHORE FLOW MAY RESULT IN A LITTLE MORE INLAND SPREAD OF MORNING
CLOUDS BY FRI AND SAT. TEMPS ARE LIKELY TO CONTINUE TO TOP OUT IN
THE 90S IN INLAND VALLEYS. WILL CONTINUE WITH THE HEAT ADVISORY
THROUGH FRI...BUT UNLESS ONSHORE FLOW STRENGTHENS MORE THAN EXPECTED
LATE THIS WEEK WOULD EXPECT A GOOD POSSIBILITY OF THE ADVISORY
NEEDING TO BE EXTENDED LATER ON.

.LONG TERM...THE STRONG RIDGE EXTENDING NW TO SE ACROSS THE REGION
AT THE END OF THE WEEKEND IS EXPECTED TO GRADUALLY ERODE AS THE HIGH
CONSOLIDATES OVER THE NE PACIFIC OFF THE BC COAST. A LOW OVER
WESTERN CANADA AND ANOTHER OFF THE CA COAST ARE EXPECTED TO WEAKEN
THE RIDGE LEAVING THE FORECAST AREA UNDER A COL. AFTER ANOTHER HOT
DAY OR TWO SUN INTO MON...THE DEVELOPING TROUGHINESS ALOFT WILL
LOWER HEIGHTS AND ENCOURAGE A STRONGER ONSHORE FLOW. THIS IS LIKELY
TO RESULT IN COOLER TEMPS TUE AND WED AND MORE MARINE CLOUDS PUSHING
INLAND. THE REGION WILL ALSO BECOME MORE SUSCEPTIBLE A SOUTHERLY
FLOW ALOFT AT TIMES SPREADING MOISTURE AND INSTABILITY ALOFT UP FROM
THE S.
&&

.AVIATION...OVERALL WIDESPREAD VFR PERSISTS NEXT 24 HRS UNDER DRY
SW FLOW ALOFT WITH CLEAR SKIES. THE ONLY EXCEPTION WILL BE AREAS
OF LIFR STRATUS ALONG CENTRAL OREGON COAST AND SOUTHWARD THROUGH
AT LEAST 19Z-21Z THU. LIKELY BE MORE CLEAR TO N...WITH SOME
PATCHY LOW CLOUDS OR FOG ONLY TO N OF KTMK.

KPDX AND APPROACHES...DRY SW FLOW ALOFT...WITH CLEAR SKIES. NW
WINDS WILL DROP OFF AFTER 06Z. ROCKEY/27

&&

.MARINE...PRETTY PERSISTENT PATTERN FOR THE NEXT FEW DAYS. HIGH
PRES TO REMAIN ANCHORED OVER THE NE PAC THRU SAT THEN GRADUALLY
WEAKEN. THERMALLY-INDUCED SURFACE TROUGH WILL PERSIST ALONG THE N
CAL AND S OREGON COAST FOR THE NEXT COUPLE OF DAYS...WHICH WILL
MAINTAIN SMALL CRAFT ADVISORY WIND SPEEDS OVER THE MAJORITY OF THE
WATERS. STRONGEST WIND WILL CONTINUE TO BE SOUTH OF CASCADE HEAD
WITH GUSTS UP TO 30 KT DURING FROM THE AFTERNOON TO EARLY EVENING
HOURS. WIND WILL EASE LATE IN THE WEEK AND OVER THE WEEKEND AS
GRADIENTS DIMINISH. MODELS IN GENERAL AGREEMENT SHOWING A SWITCH
TO A FAIRLY LIGHT SOUTH TO SOUTHWEST WIND LATE SUN.

NW SWELL 5 TO 7 FT WILL CONTINUE...BUT WILL HAVE SOME WIND-WAVE
DRIVEN SEAS AS WELL FOR THE NEXT FEW DAYS...WITH STEEP AND CHOPPY
CONDITIONS. A BUILDING NW SWELL LOOKS TO ARRIVE LATE FRI AND
SAT...POSSIBLY REACHING 10 FT.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HEAT ADVISORY UNTIL 9 PM PDT FRIDAY FOR CASCADE FOOTHILLS IN
     LANE COUNTY-CENTRAL COAST RANGE OF WESTERN OREGON-CENTRAL
     COLUMBIA RIVER GORGE-CENTRAL WILLAMETTE VALLEY-GREATER
     PORTLAND METRO AREA- LOWER COLUMBIA-NORTHERN OREGON CASCADE
     FOOTHILLS-SOUTH WILLAMETTE VALLEY-UPPER HOOD RIVER VALLEY-
     WESTERN COLUMBIA RIVER GORGE.

WA...HEAT ADVISORY UNTIL 9 PM PDT FRIDAY FOR CENTRAL COLUMBIA RIVER
     GORGE-GREATER VANCOUVER AREA-I-5 CORRIDOR IN COWLITZ COUNTY-
     SOUTH WASHINGTON CASCADE FOOTHILLS-WESTERN COLUMBIA RIVER
     GORGE.

PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM PDT FRIDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER TO FLORENCE OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 4 AM
     TO 8 AM PDT THURSDAY.

&&

$$

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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