AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
248 AM PST SAT FEB  4 2012

.SYNOPSIS...AN UPPER LEVEL RIDGE WILL REMAIN OVER THE NORTHWEST U.S.
FOR SEVERAL MORE DAYS FOR DRY WEATHER. SURFACE HIGH PRESSURE WILL
REMAIN ENTRENCHED EAST OF THE CASCADES AND WILL MAINTAIN THE OFFSHORE
WIND FLOW...THOUGH NOT QUITE AS STRONG SATURDAY AND SUNDAY AS IT WAS
ON FRIDAY. A SYSTEM OUT NEAR 140W EARLY THIS MORNING WILL LIFT NORTH
OFF THE COAST TONIGHT AND EARLY SUNDAY AND BRUSH OUR COASTAL WATERS
WITH SOME CLOUDS THAT MAY GET CLOSE TO THE COAST. 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...THE UPPER LEVEL RIDGE THAT HAS BEEN OVER THE AREA THE
LAST COUPLE OF DAYS WILL CONTINUE OVER THE PACIFIC NORTHWEST INTO
NEXT WEEK. A DISSIPATING SYSTEM THAT LIFTED NORTH BUT REMAINED OFF
THE COAST FRIDAY APPEARS TO HAVE SPREAD SOME LOW CLOUDS INTO OUR
COASTAL WATERS AND CLOSE TO THE COAST OVERNIGHT AS IT TURNED THE WIND
FLOW OVER THE WATERS TO MORE SOUTHERLY...BUT IN THE LAST HOUR OR TWO
THESE CLOUDS HAVE NOW MOVED AWAY FROM THE COAST AND OUT OF MOST OF
THE COASTAL WATERS...THUS LOOK FOR ANOTHER SUNNY BUT BREEZY DAY.

PRESSURE GRADIENTS THAT PEAKED AT NEAR 10 MB OFFSHORE FROM KTTD TO
KDLS FRIDAY WERE NOW NEAR 7 MB AND ARE EXPECTED TO REMAIN IN THAT
RANGE TODAY AND SUNDAY. THUS LOOK FOR PEAK WINDS IN THE WESTERN END
OF THE GORGE CLOSER TO 50 MPH VERSUS THE OVER 70 MPH THAT OCCURRED AT
CROWN POINT FRIDAY. THIS IS ENOUGH TO KEEP MUCH OF OUR AREA FREE OF
NIGHT AND MORNING FOG OR FREEZING FOG. WE MIGHT START TO SEE A
LITTLE FOG FORM THE NEXT COUPLE OF MORNINGS MAINLY IN THE SOUTH
WILLAMETTE VALLEY AND POSSIBLY NORTH OF KELSO. OTHERWISE LOOK FOR
RATHER COLD MORNINGS IN WIND SHELTERED AREAS AND A BIT ABOVE AVERAGE
TEMPERATURES IN THE AFTERNOONS.

THERE IS A DECENT LOOKING SYSTEM OUT NEAR 140W EARLY THIS MORNING...
BUT THE MODELS ALL SAY IT WILL LIFT NORTH BUT REMAIN OFF THE COAST
TONIGHT AND EARLY SUNDAY. WE MAY SEE SOME HIGHER CLOUDS FROM IT
INLAND. THE FAR OUTER COASTAL WATERS MIGHT GET BRUSHED WITH A FEW
SPRINKLES...WITH SOME LOWER CLOUDS MOVING INTO THE COASTAL WATERS AS
WINDS TURN A BIT SOUTHERLY AGAIN...BUT IT IS NOT CLEAR WHETHER ANY OF
THESE LOWER CLOUDS WILL REACH THE COAST. THE WINDS TURN MORE
OFFSHORE AGAIN SUNDAY AFTERNOON PUSH ANY LOW CLOUDS AWAY.

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.

I AM RATHER LUKEWARM ON THE AIR STAGNATION ADVISORY DUE TO THE
AMOUNT OF OFFSHORE FLOW THROUGH OUR AREA AND TRANSPORT WINDS EVEN
AWAY FROM THE GORGE...AND CONSIDERING HOW WEAK THE INVERSION HAS
BEEN GETTING AND WILL CONTINUE TO GET IN THE AFTERNOONS EVEN AWAY
FROM THE GORGE. WILL LET IT RIDE FOR NOW AS THE OFFSHORE WINDS WILL
BE THE WEAKEST THEY ARE GOING TO BE IN THIS EPISODE TODAY AND
SUNDAY. TOLLESON

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS.
DRY PATTERN HOLDS THROUGH A MUCH DEEPER LOW IN THE ERN PACIFIC
APPROACHES THE COAST LATE MONDAY INTO TUESDAY. THIS COUPLED WITH A
COLDER AIR MASS DROPPING SOUTH OUT OF CANADA INTO THE NORTHERN
ROCKIES WILL ALLOW THE OFFSHORE GRADIENT TO BECOME EVEN STRONGER.
MODELS CONTINUE TO ADVERTISE A WEAK SYSTEM PUSHING THROUGH THE RIDGE
ON TUE. HOWEVER...IT LOOKS LIKE A LOT OF THE UPPER LEVEL ENERGY WILL
DIVE SOUTH INTO CALIFORNIA...LIMITING THE IMPACTS FOR THE FORECAST
AREA. IT APPEARS THE COAST AND SOUTHERN INLAND AREAS STAND THE BEST
CHANCE TO GET SOME LIGHT PRECIP TUE. AFTER THIS SYSTEM...THE RIDGE
WILL REBUILD AGAIN...KEEPING THE WEATHER QUIET FOR ANOTHER COUPLE OF
DAYS. WEISHAAR/BROWN
&&

.AVIATION...VFR IS EXPECTED TO DOMINATE THE AREA THROUGH AT LEAST
SUN. THERE IS A CHANCE OF LOCAL IFR FOG IN THE CENTRAL AND SOUTH
WILLAMETTE VALLEY IN THE MORNINGS. IFR STRATUS IS LIKELY TO DEVELOP
EAST OF CASCADE LOCKS. LOW CHANCES FOR IFR STRATUS TO REACH THE KONP
AREA LATE TONIGHT...HOWEVER CONFIDENCE NOT HIGH ENOUGH TO INCLUDE A
IFR CEILING IN THE TERMINAL FORECAST AT THIS TIME.

KPDX AND APPROACHES...VFR CONDITIONS THROUGH SAT WITH DRY LIGHT TO
MODERATE EAST WINDS.
&&

.MARINE...WINDS WILL REMAIN BELOW ADVISORY CRITERIA FOR THE NEXT FEW
DAYS AS HIGH PRESSURE ANCHORS ITSELF INLAND. THE NEXT CHANCE OF SMALL
CRAFT ADVISORY WINDS LOOKS TO BE MON AND TUE WITH THE NEXT
FRONT...BUT THIS SYSTEM WILL LIKELY WEAKEN AND SPLIT AS IT APPROACHES
THE COAST SO THE MODELS MAY BE OVERESTIMATING THE WINDS AT THIS TIME.

SEAS ARE CURRENTLY 10 TO 13 FT THROUGH TODAY...THEN SLIPS BELOW 10 FT
LATER TONIGHT. ANOTHER BATCH OF SWELL ARRIVES TUE BRINGING SEAS TO
AROUND 12 FT.
&&

.PQR WATCHES/WARNINGS/ADVISORIES...
OR...AIR STAGNATION ADVISORY UNTIL 4 AM PST TUESDAY FOR CENTRAL
     WILLAMETTE VALLEY-LOWER COLUMBIA-SOUTH WILLAMETTE VALLEY.

WA...AIR STAGNATION ADVISORY UNTIL 4 AM PST TUESDAY FOR I-5 CORRIDOR
     IN COWLITZ COUNTY-SOUTH WASHINGTON CASCADE FOOTHILLS.

PZ...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 AM PST SUNDAY
     FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
     60 NM.

     SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL
     4 PM PST THIS AFTERNOON.

&&

$$

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.