FXUS66 KPQR 222214
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
213 PM PST TUE DEC 22 2009
.SYNOPSIS...DRY WEATHER WILL PREVAIL FROM TONIGHT THROUGH AT LEAST
CHRISTMAS AS A STRONG UPPER LEVEL RIDGE BUILDS ALONG THE COAST.
BRISK EAST WINDS WILL DEVELOP NEAR THE COLUMBIA RIVER GORGE
WEDNESDAY NIGHT AND WILL LIKELY CONTINUE THROUGH THE WEEKEND AS THE
RIDGE CONTINUES TO HOLD. THE NEXT CHANCE OF RAIN MAY HOLD OFF UNTIL
EARLY NEXT WEEK.
&&
.SHORT TERM...AN UPPER LEVEL RIDGE WILL BUILD OVERHEAD TONIGHT AND
WEDNESDAY. THE MODELS ARE NOW IN BETTER AGREEMENT KEEPING US DRY
THROUGH THE SHORT TERM. THE MAIN FORECAST ISSUES IN THE WEDNESDAY-
FRIDAY TIME FRAME WILL BE THE DEVELOPMENT OF GUSTY EAST WINDS NEAR
THE GORGE AND VALLEY FOG AWAY FROM THE GORGE. LOW CLOUDS AND FOG
WILL LIKELY BECOME QUITE PERSISTENT IN THE SOUTH VALLEY BY FRIDAY
WITH VERY LITTLE AFTERNOON CLEARING.
.LONG TERM...AN UPPER LEVEL RIDGE PERSISTS THROUGH THE FORECAST AREA
THROUGH THE END OF THE WEEK. MODELS VARY SIGNIFICANTLY WITH THE
BREAKDOWN OF THE RIDGE NEXT WEEKEND AND THE ARRIVAL OF ANY
SUBSEQUENT SYSTEMS...AS SHOWN BY INCREASING ENSEMBLE SPREADS. EXPECT
A SLIGHT CHANCE OF PRECIP SOMETIME LATE SAT/EARLY SUN THROUGH EARLY
NEXT WEEK...WITH A STRONG SYSTEM APPROACHING THE REGION BY MID NEXT
WEEK. HAVE KEPT POPS SLIGHTLY BELOW CLIMATOLOGY GIVEN THE CONTINUED
INFLUENCE OF THE RIDGE AND MODEL INCONSISTENCIES. RAMIREZ
&&
.AVIATION...FLOW NOW TURNING MORE NORTHERLY. CLOUDS REFORMED IN THE
EARLY AFTERNOON...WITH MOSTLY HIGH END MVFR TO LOW END VFR.
HOWEVER...AS AIR MASS STABILIZES THIS AFTERNOON AND TONIGHT...WILL
SEE LARGE AREAS OF CLEARING. BUT THAT CLEARING WILL INCREASE THE
THREAT OF FOG AND LOW CLOUDS. AT THIS TIME...WILL SEE AREAS OF FOG
FORMING OVER INLAND AREAS AFTER 08Z...AND PERSISTING WELL INTO WED
AM.
KPDX AND APPROACHES...BROKEN MVFR CIGS...AROUND 3000 FT...UNTIL
01Z...THEN GRADUAL CLEARING. WILL SEE FOG OR IFR STRATUS FORMING
AROUND KPDX OPS AREA BETWEEN 08Z AND 11Z TONIGHT. SUSPECT WILL WIND
UP WITH MORE LOW STRATUS AT KPDX THAN FOG...AND WILL TREND 00Z TAF
IN THAT DIRECTION.
&&
.MARINE...NO MAJOR CHANGES. HIGH PRES OFFSHORE WILL SLOW SHIFT
INLAND OVER PAC NW OVER THE NEXT FEW DAYS. THIS WILL BRING LIGHTER
OFFSHORE WINDS LATER TONIGHT AND WED. SEAS OF 12 TO 14 FT AT THE
MOMENT...BUT THESE TOO ARE ON THE DECREASE. SHOULD FALL BELOW 10 FT
LATER TONIGHT. NO MAJOR WEATHER EXPECTED FROM WED THROUGH EARLY SAT
AS HIGH PRES OVER PAC NW KEEPS LIGHT OFFSHORE WINDS CONTINUING.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 9 PM PST TONIGHT
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR FROM
10 TO 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 10 PM
PST THIS EVENING.
&&
$$
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.