Area Forecast Discussion
Issued by NWS Portland, OR

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FXUS66 KPQR 241002
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
302 AM PDT FRI OCT 24 2014

.SYNOPSIS...A WARM FRONT WILL SPREAD LIGHT RAIN INTO SW OREGON
THIS MORNING AND ACROSS NW OREGON AND SW WASHINGTON IN THE
AFTERNOON AND EVENING. A COLD FRONT WILL PUSH INLAND SATURDAY
AFTERNOON AND EVENING...AND POSSIBLY PRODUCE A BRIEF PERIOD OF STRONG
WIND GUSTS ALONG THE COAST. AN UPPER TROUGH WILL CONTINUE SHOWERS
THROUGH SUNDAY. ANOTHER FRONTAL SYSTEM IS EXPECTED EARLY NEXT WEEK.

&&

.SHORT TERM...FRIDAY THROUGH MONDAY...RADAR IMAGERY SHOWS THAT
SHOWERS HAVE MOSTLY EASED THIS MORNING BUT STRATIFORM RAIN WILL
RETURN FROM SOUTH TO NORTH THROUGH THE AFTERNOON AS A WARM FRONT
LIFTS OVER THE AREA. THIS WILL ALSO INDUCE OFFSHORE LOW-LEVEL FLOW
THROUGH THE COLUMBIA GORGE AS PRESSURE GRADIENTS INCREASE. THE NORTH
ZONES SHOULD BE DRY FOR AT LEAST THE FIRST HALF OF TODAY AHEAD OF THE
APPROACHING WARM FRONT.

A LOW WELL OFFSHORE NORTHERN CALIFORNIA CONTINUES TO DEEPEN OVERNIGHT
TONIGHT INTO SAT MORNING. ALTHOUGH MODELS AGREE FAIRLY WELL ON THE
TRACK OF THE LOW...AND THE GFS HAS CONSOLIDATED THE SYSTEM INTO ONE
SINGLE LOW INSTEAD OF AN ELONGATED TWO...THERE ARE STILL
DISCREPANCIES ON THE STRENGTH. RAIN IS CERTAIN BASED ON THE TRACK BUT
WINDS WILL DEPEND VERY MUCH ON THE STRENGTH OF THE LOW SO CONFIDENCE
IS LOWER IN THAT REGARD WITH THE SYSTEM. THE NAM AND ECM SHOW
SLIGHTLY SW FLOW THROUGH THE WILLAMETTE VALLEY SATURDAY EVENING WHICH
WOULD BE MORE FAVORABLE FOR HIGHER WINDS THAN THE SLIGHTLY SE FLOW
DEPICTED BY THE GFS. FAVORED THE NAM/ECM SOLUTION WITH COASTAL WIND
GUSTS UP TO 60 MPH SATURDAY AFTERNOON...PARTICULARLY ON THE IMMEDIATE
CENTRAL OREGON COAST...AND VALLEY WIND GUSTS UP TO ABOUT 45 MPH
SATURDAY EVENING BUT THESE NUMBERS MAY CHANGE AS THE MODELS HOPEFULLY
COME INTO BETTER AGREEMENT.

A BROAD UPPER TROUGH...SIMILAR TO WHAT WAS OVER THE AREA
THURSDAY...SETTLES OVER THE REGION SUNDAY. THIS WILL BRING ADDITIONAL
SHORT-WAVES THROUGH THE FORECAST AREA SAT NIGHT AND SUNDAY. SNOW
LEVELS FALL TO NEAR CASCADE PASS LEVELS SUNDAY. WEAK RIDGING MOVES
OVER THE AREA SUNDAY NIGHT AND INTO MONDAY MORNING WITH RAIN CHANCES
DWINDLING BRIEFLY BEFORE THE NEXT SYSTEM APPROACHES. BOWEN/TJ

.LONG TERM...MONDAY NIGHT THROUGH THURSDAY NIGHT...AN ACTIVE WEATHER
PATTERN CONTINUES THROUGH NEXT WEEK. THE NEXT FRONTAL
SYSTEM...INCLUDING THE REMNANTS OF HURRICANE ANA...WILL MOVE THROUGH
THE REGION MONDAY NIGHT INTO TUESDAY BRINGING CONTINUED RAIN AND
WINDS ALONG THE COAST. SHORTWAVES WILL SUPPORT RAIN THROUGH
WEDNESDAY. BEGINNING AROUND THURSDAY THE MODELS DIVERGE SIGNIFICANTLY
TO THE EXTENT THAT CLIMO SEEMS THE BEST BET AT THIS POINT FOR THE
REMAINING 24 HRS OF THE FORECAST PERIOD.  BOWEN/27

&&

.AVIATION...VFR CONDITIONS WITH A FEW SHOWERS TO CONTINUE
THROUGH ABOUT 18Z THIS MORNING...MAY BE A FEW SPOTS OF MVFR
CIGS. AFTER 18Z A WARM FRONT LIFTING N WILL SPREAD SOME RAIN N INTO
NW OREGON...BUT OVERALL CONDITIONS EXPECTED TO REMAIN VFR...WITH
RAIN DECREASING AFTER 06Z TONIGHT AS THE WARM FRONT LIFTS INTO WA.

KPDX AND APPROACHES...MAINLY VFR CONDITIONS CONTINUING TODAY AND
TONIGHT. A FEW LIGHT SHOWERS ARE POSSIBLE THROUGH 20Z...BEFORE A
MORE GENERAL RAIN DEVELOPS. ALTHOUGH UNLIKELY...THERE IS ABOUT A 10
PERCENT CHANCE FOR SEEING A SHORT PERIOD OF MVFR CIGS BEFORE 18Z.

&&

.MARINE...RATHER BENIGN CONDITIONS TODAY AS LIGHT S WINDS BACK
AROUND TO THE E LATE IN THE DAY. A LOW PRES SYSTEM IS EXPECTED TO
DEEPEN TO AROUND 995 MB AND APPROACH FROM THE SW TONIGHT...THEN MOVE
N THROUGH THE COASTAL WATERS SAT BEFORE MOVING INLAND OVER WESTERN
WA LATE SAT. THE EXACT TRACK AND STRENGTH OF THE LOW ARE STILL IN
QUESTION...BUT OVERALL EXPECTATION IS FOR SOUTHERLY GALES WITH THIS
LOW SAT. THE GALES WILL BRING STEEP SEAS WITH WAVE HEIGHTS EXPECTED
TO PEAK AROUND 17 TO 20 FT LATE SAT...BUT AGAIN...THIS WILL DEPEND
ON THE TRACK AND STRENGTH OF THE LOW.

ONCE THE LOW MOVES INLAND MON EVENING...WINDS WILL TURN TO BACK
TO THE W AND DECREASE ALONG WITH SEAS SUBSIDING. ANOTHER SYSTEM IS
EXPECTED TO APPROACH FROM THE W EARLY NEXT WEEK...AROUND MON NIGHT.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...GALE WATCH FROM LATE TONIGHT THROUGH SATURDAY EVENING FOR
     COASTAL WATERS FROM CAPE SHOALWATER WA TO CASCADE HEAD OR
     OUT 60 NM.

     SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 3 AM PDT EARLY
     THIS MORNING FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO
     FLORENCE OR OUT 60 NM.

     GALE WATCH FROM THIS EVENING THROUGH SATURDAY AFTERNOON FOR
     COASTAL WATERS FROM CASCADE HEAD OR TO FLORENCE OR OUT 60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
     7 AM PDT THIS MORNING.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 3 PM
     THIS AFTERNOON TO 8 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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