Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 231642 CCA
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
937 AM PDT WED JUL 23 2014

.SYNOPSIS...AN UNSEASONABLY STRONG AND COOL LOW PRESSURE SYSTEM WAS
CENTERED OFF THE WASHINGTON COAST THIS MORNING...WITH A COLD FRONT
MOVING THROUGH SOUTHWEST WASHINGTON AND NORTHWEST OREGON TODAY. THE
LOW CENTER WILL SWING THROUGH TONIGHT AND EARLY THURSDAY FOR
CONTINUED SHOWERS. THERE IS A CHANCE OF THUNDERSTORMS THROUGH THIS
EVENING. A FEW SHOWERS WILL LINGER THROUGH THURSDAY...OTHERWISE
HIGHER PRESSURE WILL THEN BUILD WITH DRY AND WARMER WEATHER BY FRIDAY
AND CONTINUING THROUGH THE WEEKEND INTO NEXT WEEK.
&&

.SHORT TERM...TODAY THROUGH FRIDAY...AN UNSEASONABLY COOL AND STRONG
LOW PRESSURE SYSTEM WAS CENTERED OFF THE WASHINGTON COAST THIS
MORNING...WITH A COLD FRONT CURRENTLY MOVING THROUGH SOUTHWEST
WASHINGTON AND NORTHWEST OREGON...THAT MAY NOT MOVE EAST OF THE
CASCADES UNTIL LATER TODAY. PRECIPITATION AMOUNTS WERE PRETTY
IMPRESSIVE AT THE COAST AND IN THE COAST RANGE...WITH AROUND AN INCH
NEAR TILLAMOOK AND HALF TO TWO THIRDS OF AN INCH IN THE COAST RANGE.
AMOUNTS HAVE BEEN LESS IN THE VALLEY...BUT MAY PUSH A HALF INCH IN
THE CASCADES THIS AFTERNOON. THE CLOUDS MAY START TO BREAK UP BEHIND
IT IN THE AFTERNOON AND EARLY EVENING...WITH MORE THUNDERSTORMS
LIKELY DEVELOPING WITH SMALL HAIL...GUSTY WINDS...AND HEAVY SHOWERS.
TEMPS TODAY MAY STRUGGLE TO REACH 70...DOING SO LATE IN THE DAY.

THE LOW CENTER COMES ONSHORE TONIGHT...AND THE MODELS SHOW PART OF
THE BENT BACK OCCLUSION SWINGING THROUGH OUR NORTHERN ZONES FROM
ABOUT THE COLUMBIA RIVER OR SO OVERNIGHT TONIGHT AND EARLY THURSDAY
WITH SOME POSSIBLY STEADY RAIN AND ANOTHER SHOT OF DECENT QPF
AMOUNTS. HAVE ADJUSTED THE FORECAST FOR THIS IN THE MORNING PACKAGE.

THE LOW MOVES OUT TO THE EAST THURSDAY MORNING...BUT THERE IS STILL
QUITE A BIT OF WESTERLY FLOW THROUGH THURSDAY WITH CLOUDS IN THE
NORTH FROM ABOUT SALEM SOUTH BEING SLOW TO CLEAR THURSDAY...AND A FEW
SHOWERS LINGERING THROUGH THE AFTERNOON IN THE FAR NORTH. TEMPS WILL
START TO REBOUND AND GET INTO THE LOW TO MID 70S.

AN UPPER RIDGE...THOUGH QUITE FLAT...WILL SLOWLY START TO MOVE IN
FRIDAY FOR A RETURN TO MORE SEASONABLE DRY WEATHER WITH SOME MORNING
CLOUDS AND AFTERNOON SUNSHINE. TEMPS WILL FINALLY APPROACH 80 AGAIN.
TOLLESON

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
HIGH PRESSURE WILL BUILD WESTWARD ACROSS THE CONUS AMPLIFYING AN
UPPER-LEVEL RIDGE THAT WILL SET UP OVER THE NORTHWESTERN U.S. THIS
WILL INCREASE TEMPERATURES BACK TO ABOVE NORMAL OVER THE WEEKEND.
THERE IS A POSSIBLE DISTURBANCE THAT COULD MOVE THROUGH AS EARLY AS
SUNDAY NIGHT...BUT MUCH UNCERTAINTY EXISTS IN THE TIMING OF THIS
SYSTEM AND LOCATION.  -MCCOY
&&

.AVIATION...MIX OF MVFR/VFR ACROSS THE INTERIOR THIS MORNING AS A
LINE OF RAIN MOVES INTO THE VALLEY WITH CIGS GENERALLY BETWEEN 2500
FT AND 3500 FT. EXPECT MORE WIDESPREAD MVFR IN THE COMING HOURS AS
RAIN PUSHES THROUGH THE INTERIOR WITH LOCAL IFR AT TIMES WITH HEAVIER
RAIN. MEANWHILE...MVFR TO IFR CIGS AND VSBY ALONG THE COASTAL AREAS.
THUNDERSTORMS POSSIBLE ACROSS THE REGION TODAY INTO THE EVENING
HOURS...THOUGH NOT ENOUGH CONFIDENCE TO PINPOINT TIMING OR LOCATION
IN ANY PARTICULAR TAF AT THIS TIME. CONDITIONS PROBABLY REMAIN MVFR
OR WORSE ALONG THE COAST WED NIGHT...THOUGH IMPROVEMENT TO VFR
EXPECTED ACROSS INTERIOR STARTING AROUND 03Z WED.

KPDX AND APPROACHES...EXPECT VFR TO CONTINUE FOR ANOTHER HOUR OR TWO
WITH CIGS AROUND 3000-3500 FT. NEXT LINE OF RAIN SHOULD ARRIVE AROUND
16Z WITH CONTINUED RAIN AT TIMES TODAY. ABOUT 25 PERCENT CHANCE OF
THUNDERSTORM IMPACTING THE TERMINAL OR OPS AREA TODAY THROUGH 03Z.
CULLEN
&&

.MARINE...WINDS HAVE PICKED UP EARLY THIS MORNING IN RESPONSE TO LOW
PRES SYSTEM MOVING INTO THE WATERS AND INCREASED PRES GRADIENT. AS A
RESULT...SMALL CRAFT ADVISORY IN EFFECT FOR NORTH OREGON WATERS
THROUGH TONIGHT WITH GUSTS 25 TO 30 KT POSSIBLE. PROBABLY WILL SEE
SOME OCCASIONAL GUSTS TO 20-25 KT S OF CASCADE HEAD AND OVER THE
CENTRAL OREGON INNER WATERS...BUT NOT FREQUENT ENOUGH TO EXTEND
ADVISORY SOUTHWARD. SEAS MAY BUILD SLIGHTLY TODAY...TO AROUND 5 TO 7
FT AND WILL BE SOMEWHAT STEEP WITH DOMINANT PERIODS AT 9 SECONDS.

LATER THIS WEEK...HIGH PRES REDEVELOPS OVER NE PAC AS THERMAL LOW
PRES BUILDS OVER N CALIFORNIA. THIS WILL BRING A RETURN TO GUSTY N
WINDS AND STEEP WIND DRIVEN SEAS...PARTICULARLY IN THE LATE AFTERNOON
AND EVENING HOURS FRI THROUGH THE WEEKEND.  CULLEN
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 AM PDT THURSDAY FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR OUT
     60 NM.

&&

$$

MORE WEATHER INFORMATION ONLINE AT...HTTP://WEATHER.GOV/PORTLAND

INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
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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