FXUS66 KPQR 042231
AFDPQR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
230 PM PST WED DEC 3 2008

.SYNOPSIS...A STRONG RIDGE OF HIGH PRESSURE IS BRINGING DRY WEATHER
TO THE FORECAST AREA TODAY. DRY WEATHER WILL CONTINUE THROUGH
SATURDAY. A WEAK PACIFIC FRONTAL SYSTEM WILL BRING SOME RAIN BACK TO
THE FORECAST AREA SATURDAY NIGHT AND SUNDAY. MORE FRONTAL SYSTEMS
WILL AFFECT THE AREA THROUGH THE MIDDLE OF NEXT WEEK.

&&

.SHORT TERM...SATELLITE IMAGERY SHOWS THAT THE STRONG OFFSHORE
SURFACE GRADIENT HAS HELPED TO BRING CLEAR SKIES TO THE ENTIRE
FORECAST AREA THIS AFTERNOON. EASTERLY SURFACE WINDS ARE GUSTING IN
THE 30S THROUGH THE COLUMBIA RIVER GORGE AND ACROSS THE MOUNTAINS.

AN UPPER LEVEL HIGH PRESSURE AREA NOSES INTO WESTERN ORE FRI.
OFFSHORE FLOW WILL BE WEAK ON FRI WITH SOME EAST WINDS NEAR THE GORGE
BUT THE AREAS AWAY FROM THE GORGE WILL HAVE VERY LIGHT WINDS WHICH
WILL ALLOW FOG/STRATUS TO REMAIN IN THE SOUTHERN VALLEY AND MORE
EXTENSIVE FOG AND STRATUS THROUGHOUT THE VALLEY FRIDAY NIGHT AND
SATURDAY.

MODELS HAVE CONTINUED TO SLOW DOWN THE PROGRESS OF THE NEXT FRONTAL
SYSTEM. CURRENT MODELS HAVE THE PRECIPITATION AHEAD OF THE FRONT
NOT REACHING OUR COAST UNTIL LATE SAT AFTERNOON AND SPREADING INTO
THE REMAINDER OF THE FORECAST AREA LATE SAT NIGHT. LIKENS

.LONG TERM...A WEAK COLD FRONT WILL MOVE THROUGH THE AREA
SUN...FLATTENING THE UPPER LEVEL RIDGE. THIS FEATURE DESTABILIZES THE
ATMOSPHERE BRINGING COOL SHOWERY WEATHER AS WELL AS TRIGGERING A
STRONG PUSH OF MARINE AIR. THE WEATHER PATTERN TURNS MORE ACTIVE NEXT
WEEK AS THE JET STREAM STARTS MIGRATING SOUTHWARD. A PACIFIC FRONTAL
SYSTEM IS EXPECTED MON NIGHT/TUE...HOWEVER THE EXACT TIMING IS STILL
UNCERTAIN. MODELS DIVERGE SIGNIFICANTLY BY DAY SEVEN AND WILL GO WITH
PERSISTENCE AT THIS TIME.

&&

.AVIATION...THE ENTIRE FORECAST AREA IS BASICALLY CLEAR AS OFFSHORE
FLOW HAS CLEARED OUT ALL THE FOG AND LOW STRATUS OUT. WILL PROBABLY
SEE SO LOCAL IFR RETURN IN THE SOUTHERN WILLAMETTE VALLEY AND
POSSIBLY NORTH OF KKLS BUT DUE TO WARMING UP AND DRYING OUT DURING
THE DAY TODAY EXPECT FORMATION TO BE RATHER LATE. ONCE IT FORMS NEAR
KEUG TONIGHT...MAY BE A BIT SLOW TO CLEAR FRIDAY AFTERNOON DUE TO
LIGHT GRADIENTS. ANYTHING AT THE COAST WILL BE VERY PATCHY LATE
TONIGHT AND FRIDAY MORNING.

KPDX AND APPROACHES...VFR TONIGHT AND FRIDAY WITH EAST WINDS TO 30
KT OR SO TOWARDS KTTD...LESS TOWARD KHIO...WEAKENING LATER TONIGHT
AND FRIDAY. POSSIBLY SOME PATCHY IFR LATE TONIGHT AND EARLY FRIDAY
WESTERN APPROACHES NEAR KHIO BUT THIS IS NOT CERTAIN. TOLLESON
&&

.MARINE...STILL DEALING WITH SOME LONGER PERIOD SWELL THOUGH PERIODS
EASING BACK TO 15 TO 16 SECONDS AND WILL CONTINUE TO SHORTEN TO 12
SECONDS FRIDAY. SEAS 12 FT AT BUOY 89 WILL KEEP SEAS AROUND 10 FT OR
MORE IN OUR WATERS FOR AWHILE TONIGHT. WINDS MARGINAL BUT WILL KEEP
A SMALL CRAFT ADVISORY FOR THE EVENING FOR EASTERLY GAP WINDS IN THE
INNER WATERS AND A LITTLE MORE NORTHERLY IN THE SOUTHERN OUTER
WATERS. WINDS QUITE LIGHT FRIDAY. A WEAK FRONT OVER THE WEEKEND MAY
BRING SOUTH WINDS UP CLOSE TO SMALL CRAFT LEVELS. TOLLESON
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR/WA...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA BAR THIS EVENING.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS CAPE SHOALWATER TO
FLORENCE THROUGH THIS EVENING.
SMALL CRAFT ADVISORY FOR WINDS CAPE SHOALWATER TO FLORENCE
OUT 20 NM THROUGH EARLY TONIGHT.
SMALL CRAFT ADVISORY FOR WINDS CASCADE HEAD TO FLORENCE 20
TO 60 NM OFFSHORE THROUGH EARLY TONIGHT.

&&

$$

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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