FXUS66 KPQR 121046
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
246 AM PST FRI MAR 12 2010

.SYNOPSIS...THE FRONTAL BOUNDARY WHICH HAS BEEN NEARLY STATIONARY
WILL PUSH INLAND TODAY AS A COLD FRONT. THE UPPER TROUGH WILL MOVE
THROUGH TONIGHT WITH THE AIR MASS SLOWLY STABILIZING SATURDAY. HIGH
PRESSURE WILL START TO BUILD OVER THE AREA SATURDAY AFTERNOON. DRY
AND WARMER CONDITIONS WILL PREVAIL SUNDAY THROUGH EARLY NEXT WEEK
EXCEPT POSSIBLY NEAR THE COAST.

&&

.SHORT TERM...BAROCLINIC ZONE HAS BECOME A BIT MORE N-S ORIENTED
OVERNIGHT WITH RADAR SHOWING THE HEAVIER RAIN IN THE VICINITY OF THE
COAST RANGE. UPSTREAM NEAR 135W A COLD SHORT WAVE HAS BEEN DRIVING
EASTWARD S OF THE MAIN LOW CENTER. AS THIS SYSTEM CONTINUES TO THE E
TODAY THE FRONTAL BAND WILL BE FORCED TO PUSH E ACROSS THE FORECAST
AREA. MODELS HAVE BEEN CONSISTENT SHOWING THE COLD FRONT MOVING INTO
THE CASCADES THIS AFTERNOON WITH LOWERING SNOW LEVELS AS COOLER AIR
ARRIVES. WRFGFS SUGGESTS CASCADES COULD GET SNOW ADVISORY AMOUNTS
THIS AFTERNOON...BUT EXPECT THE HEAVIER AMOUNTS TO BE ABOVE PASS
LEVELS.

COASTAL RIVERS SHOULD SEE EXPERIENCE MODERATE RISES WITH ANOTHER 6
HOURS OF DECENT RAIN...UP TO AROUND AN INCH OF ADDITIONAL QPF FOR THE
CENTRAL COAST AND COAST RANGE.

MARGINAL HIGH WIND WARNING CURRENTLY VERIFYING FOR THE CENTRAL COAST
WITH NAM SHOWING 55-60 KT AT 925 MB JUST OFFSHORE. WINDS SHOULD DROP
OFF BE MID MORNING AS THE FRONT BEGINS TO PUSH ONSHORE.

THE UPPER TROUGH MOVES THROUGH TONIGHT WITH ANOTHER SHOT OF SUB
WARNING WIND FOR THE S WA/N OREGON COAST AS AN ASSOCIATED SURFACE LOW
MOVES INTO THE N WA COAST. DECREASING SHOWERS SAT AS THE MOIST LOW
LEVEL AIR MASS STABILIZES.

AN UPPER RIDGE BUILDS OVER THE PAC NW SAT NIGHT AND SUN...BUT THE
RIDGE AXIS APPEARS TO CENTERED NEAR THE ID BORDER. THIS LEAVES
COASTAL AREAS VULNERABLE TO A PASSING WARM FRONT SUN AND SUN NIGHT.
RW

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...REASONABLY
GOOD AGREEMENT AMONGST GUIDANCE FOR LATE THIS WEEKEND THROUGH
MON...SHOWING A RIDGE HOLDING IN OVER THE INTERIOR PAC NW...WITH A
DEEP TROUGH PROGRESSING SLOWLY FROM 150W TO 140W.WITH A BAROCLINIC
ZONE OFFSHORE THROUGH MON...SO WILL GO A WITH PREDOMINANTLY DRY AND
MILD FORECAST SUN AND MON. GENERAL TREND FOR TUE ON SHOWS A SHORTWAVE
AND COLD FRONT LIFTING NE AND PUSHING INLAND...BUT TIMING BECOMES AN
ISSUE WITH GFS THE MOST PROGRESSIVE WITH THE SYSTEM. GIVEN THE
DEVELOPING MODEL DISCREPANCIES...WILL TREND FORECAST TOWARD
CLIMATOLOGY AFTER TUE.

&&

.AVIATION...MVFR/IFR CONDITIONS ALONG THE COAST AND N WILLAMETTE
VALLEY THROUGH 19Z THIS MORNING...WHILE GENERALLY VFR IN THE S
VALLEY. AS MAIN PRECIP SHIELD LIFTS N BY 12Z FRI...EXPECT
IMPROVING CONDITIONS IN THE N WILLAMETTE VALLEY...BUT NOT LIKELY
TO IMPROVE MUCH ON THE COAST. MVFR CIGS AND MVFR/IFR VIS IN RAIN
EXPECTED TO ACCOMPANY THE FRONT TODAY.

KPDX AND APPROACHES...PREVAILING MVFR CONDITIONS...THEN SOME
TEMPORARY IMPROVEMENT EXPECTED BEFORE THE COLD FRONT ARRIVES TODAY.

&&

.MARINE...WINDS CURRENTLY REACHING GALE FORCE IN THE EARLY
MORNING HOURS AS COLD FRONT PUSHES ACROSS THE WATERS. WINDS WILL
SLOWLY DROP OFF BEHIND THE FRONT TODAY THOUGH AS A SURFACE LOW
TRAILING THE FRONT MOVES THROUGH THE WA COASTAL WATERS. POSSIBLE
GALE FORCE WINDS FOR THE N WATERS LATE FRI. SEAS SHOULD
REMAIN AROUND 20 FT...BUT BEGIN SUBSIDING LATER THIS MORNING.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH SURF ADVISORY UNTIL 7 AM PST THIS MORNING FOR CENTRAL
OREGON COAST-NORTH OREGON COAST.

HIGH WIND WARNING UNTIL 10 AM PST THIS MORNING FOR CENTRAL
OREGON COAST.

WA...HIGH SURF ADVISORY UNTIL 7 AM PST THIS MORNING FOR SOUTH
WASHINGTON COAST.

PZ...GALE WARNING UNTIL 4 PM PST THIS AFTERNOON FOR COASTAL WATERS
FROM CAPE SHOALWATER WA TO FLORENCE OR OUT TO 60 NM.

SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 PM
PST THIS EVENING FOR COLUMBIA RIVER BAR.

&&

$$

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

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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