FXUS66 KPDT 011036
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
235 AM PST TUE DEC 1 2009
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...THE COLD FRONT HAS
PUSHED SOUTH OF THE CWA. AREAS FOG AND/OR STRATUS REMAIN IN THE
LOWER COLUMBIA BASIN. SOME CLOUDS REMAIN IN THE NORTHERLY UPSLOPE
FLOW INTO THE BLUE MOUNTAINS. OTHER THAN A FEW SNOWTEL LOCATIONS NO
STATIONS REPORTED ANY PRECIPITATION WITH THE FRONT...ALTHOUGH RADAR
MAY HAVE SOME SPRINKLES MIXED WITH THE GROUND CLUTTER. WILL MAKE A
LAST MINUTE DECISION ON CLOUD COVER THIS MORNING BASED ON LATEST
SATELLITE/OBS. WITH UPSLOPE CONTINUING TODAY AND LIMITED MID LEVEL
MOISTURE DECIDED TO LEAVE ISOLATED SHOWERS IN BLUE AND WALLOWA
MOUNTAINS THIS MORNING EVEN THOUGH I EXPECT PRECIPITATION WILL BE
SPRINKLES/FLURRIES AT MOST. BY THIS AFTERNOON THE DRIER NORTHERLY
FLOW BEHIND THE FRONT WILL BE MORE IMPORTANT THAN UPSLOPE LIFT...SO
DO NOT EXPECT EVEN SPRINKLES/FLURRIES.
THE UPPER LEVEL RIDGE WILL BUILD OFFSHORE TODAY THROUGH WEDNESDAY
NIGHT WITH DRY NORTHERLY FLOW OVER EASTERN WASHINGTON AND OREGON.
THIS WILL BRING COLDER AIR INTO THE AREA. WITH LIGHT WINDS AND CLEAR
SKIES PATCHY FOG WILL REDEVELOP UNDER STRONG SURFACE INVERSIONS IN
THE LOWER COLUMBIA BASIN AGAIN TONIGHT AND WEDNESDAY NIGHT. OUTSIDE
OF FOG/STRATUS AREAS SKIES WILL BE MOSTLY CLEAR BY TONIGHT EXCEPT
FOR OCCASIONAL CIRRUS MOVING THROUGH THE RIDGE. COONFIELD
.LONG TERM...THURSDAY THROUGH TUESDAY...HIGH PRESSURE WILL KEEP THE
AREA DRY UNDER MOSTLY CLEAR SKIES ON THURSDAY. A TROUGH IS THEN
EXPECTED TO MOVE INTO BRITISH COLUMBIA ON FRIDAY...BREAKING DOWN THE
RIDGE OF HIGH PRESSURE AND POSSIBLY SENDING ENOUGH ENERGY SOUTHWARD
TO INDUCE A FEW MOUNTAIN SHOWERS. WITH THIS BREAK DOWN OF THE
RIDGE...SATURDAY AND SUNDAY WILL SEE NORTHWESTERLY FLOW ALOFT THAT
WILL BRING PARTLY CLOUDY SKIES...AS WELL AS COOLER AIR AND A CHANCE
FOR UPSLOPE MOUNTAIN SNOW SHOWERS. ALTHOUGH THERE ARE NUMEROUS MODEL
DIFFERENCES DURING THIS TIME PERIOD...THERE IS A GENERAL CONSENSUS
THAT LARGE SCALE TROUGHING OVER THE CENTRAL U.S. WILL SWING
AN UPPER LOW INTO THE REGION ON SUNDAY NIGHT AND MONDAY. THIS
FEATURE WILL INCREASE PRECIPITATION CHANCES AND AT THE SAME TIME
BRING MUCH COLDER AIR TO THE INTERIOR NORTHWEST. THEREFORE...ANY
PRECIPITATION THAT DOES FALL SUNDAY THROUGH TUESDAY WILL MOST LIKELY
BE IN THE FORM OF SNOW. 82
&&
.AVIATION...12Z TAFS...LOW CLOUDS AND FOG HAVE ADVECTED FROM NORTH
CENTRAL WASHINGTON INTO THE LOWER COLUMBIA BASIN. THIS HAS CAUSED
VISIBILITIES AS LOW AS 1/4SM AT KPSC AND KALW. AT KYKM...VISIBILITY
HAS NOT FALLEN BELOW 4SM...BUT THIS COULD CHANGE WITHOUT NOTICE.
DENSE FOG IS NOT EXPECTED AT KDLS...KPDT OR KRDM...BUT KDLS AND KPDT
COULD SEE VISIBILITIES DROP TO MVFR CONDITIONS AT SOME POINT THIS
MORNING. CONDITIONS WILL IMPROVE AROUND MID-DAY TUESDAY AS MID AND
LOWER LEVEL DRY AIR PUSHES IN FROM THE NORTH. WINDS WILL REMAIN LESS
THAN 10 KTS. 82
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 41 26 40 20 / 10 0 0 0
ALW 39 26 40 22 / 10 0 0 0
PSC 37 23 38 23 / 0 0 0 0
YKM 40 23 39 21 / 0 0 0 0
HRI 38 21 37 20 / 10 0 0 0
ELN 43 22 40 19 / 0 0 0 0
RDM 41 13 42 18 / 0 0 0 0
LGD 41 18 38 15 / 10 0 0 0
GCD 43 21 41 23 / 10 0 0 0
DLS 47 28 43 26 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&
THREAT INDEX
TODAY : GREEN
WEDNESDAY : GREEN
THURSDAY : GREEN
GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES.
YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT.
FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON
$$
76/82/82
