FXUS66 KPQR 050419
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
820 PM PST SAT FEB 4 2012

.SYNOPSIS...DRY WEATHER WILL CONTINUE FOR THE NEXT SEVERAL DAYS AS AN
UPPER LEVEL RIDGE REMAINS LOCKED OVERHEAD. SURFACE HIGH PRESSURE WILL
REMAIN ENTRENCHED EAST OF THE CASCADES AND WILL MAINTAIN THE OFFSHORE
WIND FLOW...THOUGH NOT QUITE AS STRONG SUNDAY AS IT HAS BEEN
RECENTLY. A SYSTEM OFF THE COAST LATE SAT WILL LIFT NORTH OFF THE
COAST TONIGHT. OFFSHORE GRADIENTS WILL INCREASE AGAIN LATER SUNDAY
THROUGH MONDAY FOR MORE DRY WEATHER. A SPLITTING SYSTEM MAY BRING A
SMALL THREAT OF PRECIPITATION TO OUR FORECAST AREA TUESDAY.
&&

.SHORT TERM...HIGH PRES E OF THE CASCADES THIS EVENING KEEPING FLOW
OFFSHORE...WHILE ANOTHER SYSTEM LIFTS N OFF THE COAST. AS WITH
PREVIOUS OFFSHORE SYSTEMS...EXPECT LITTLE EFFECT ON THE FORECAST
AREA EXCEPT FOR SOME CLOUDS BRUSHING THE AREA. GRADIENTS THROUGH THE
GORGE STILL ON THE ORDER OF 7 MB...MAY DROP A MB OR TWO
OVERNIGHT...BUT OVERALL STILL EXPECT MORE OF THE SAME WITH JUST
SLIGHTLY REDUCED WIND SPEEDS. WITH LIGHT WINDS IN THE S WILLAMETTE
VALLEY...STILL A CHANCE FOR SOME MORNING FOG. OTHERWISE LOOK FOR
RATHER COLD MORNINGS IN WIND SHELTERED AREAS AND A BIT ABOVE AVERAGE
TEMPERATURES IN THE AFTERNOONS.

REMAINDER OF SHORT TERM DISCUSSION UNCHANGED...
THE NEXT UPSTREAM SYSTEM APPROACHES SUNDAY NIGHT AND MONDAY BUT WILL
REMAIN OFFSHORE THROUGH THIS PERIOD. MAIN EFFECT IS AN INCREASE IN
THE OFFSHORE WIND FLOW...SO LOOK FOR MORE EASTERLY BREEZES AND A
MINIMUM OF FOG. THIS SYSTEM WILL LIKELY BE SPLITTING AS IT REACHES
OUR AREA TUESDAY SO WE WILL SEE IF WE GET MUCH IF ANY PRECIPITATION
FROM IT.

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS.
MODELS BEGIN TO WEAKEN THE UPPER RIDGE OVER THE WEST COAST EARLY IN
THE WEEK...THEN BRING A TROUGH TO THE COAST TUE EVENING. THE UPPER
TROUGH SPLITS AND A CUTOFF LOW DROPS SOUTH INTO CALIF. AS THE SYSTEM
MOVES ONSHORE...MOST DYNAMICS HEAD INTO N CALIF ALTHOUGH THE LOW IS
LIKELY TO GENERATE A FEW LIGHT RAIN SHOWERS OVER THE SOUTH PORTION
OF THE CWA TUE AFTERNOON. MODELS SHOW THE UPPER RIDGE REBOUNDING TO
SOME EXTENT WED...THOUGH HOW LONG IT REMAINS OVER THE AREA IS
UNCERTAIN. ANOTHER SYSTEM IS EXPECTED TO PUSH THROUGH THE RIDGE BY
LATER FRIDAY. GFS ENSEMBLES LEAN TOWARD A MEAN RIDGE OVER THE WEST
COAST DURING THE WEEKEND THOUGH IT SUPPORTS A SPLITTING PATTERN
WHICH COULD INDICATE A CHANCE OF RAIN FOR AT LEAST PART OF THE CWA.
KELSON

&&

.AVIATION...DRY OFFSHORE FLOW WITH VFR CONDITIONS THROUGH SUNDAY.
MAY HAVE PATCHY FOG BETWEEN KCVO AND K61S...BUT NOT MUCH THREAT.
GUSTY WINDS UP TO 40 KT IN AND NEAR W COLUMBIA GORGE. ROCKEY.

KPDX AND APPROACHES...VFR WITH DRY LIGHT EAST WINDS THRU SUNDAY.
&&

.MARINE...E TO SE WINDS 15 TO 20 KT THROUGH SUN NIGHT...BUT WILL
HAVE FEW GUSTS FROM TIME TO TIME IN AND NEAR GAPS IN THE COASTAL
TERRAIN. STORM ACTIVITY WELL OFFSHORE CONTINUES TO GENERATE WEST
SWELL 10 TO 12 FT WILL CONTINUE THROUGH SUN...THEN SLOWLY SUBSIDES
BELOW 10 FT LATER SUN NIGHT.

&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM PST SUNDAY
ON ALL COASTAL WATERS.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 8 AM
PST SUNDAY.
&&

$$

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.






Back to Main Forecast Discussion Page