FXUS66 KPDT 011714 AAA
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
915 AM PST TUE DEC 1 2009
UPDATED AVIATION DISCUSSION
.SHORT TERM...TODAY AND TONIGHT...A WEAK WEATHER SYSTEM IN A
NORTHWEST FLOW IS CLIPPING THE FORECAST AREA THIS MORNING. THIS IS
BRINGING A FEW LIGHT SNOW SHOWERS TO THE BLUE MOUNTAINS. OTHERWISE
UPSLOPE FLOW IS ENHANCING LOW LEVEL CLOUDS ALONG THE FOOTHILLS OF
THE BLUE MOUNTAINS AND BLUE MOUNTAINS RESULTING IS SOME LOCALLY
DENSE FOG. THESE CONDITIONS LIKELY TO LAST THROUGH THE MORNING WITH
SOME IMPROVEMENT MIDDAY AND AFTERNOON. THERE WILL BE SOME GRADUAL
CLEARING FROM THE NORTH IN THE AFTERNOON BUT MOST OF THE FORECAST
AREA WILL REMAIN AT LEAST PARTLY CLOUDY THROUGH THE AFTERNOON. MORE
CLEARING EXPECTED TO CONTINUE OVERNIGHT WITH THE POTENTIAL FOR FOG
REDUCED BUT STILL PATCHY FOG POSSIBLE. COOLER TODAY WITH THE CLOUD
COVER AND A COOL LIGHT NORTH WIND.
&&
.AVIATION...18Z TAFS...LOW CLOUDS AND FOG CONTINUE ALONG THE
FOOTHILLS OF THE BLUE MOUNTAINS IMPACTING KPDT AND KALW. LIFR
CONDITIONS WILL GRADUALLY IMPROVE THIS MORNING AT THESE TWO TAF
LOCATIONS. LOW CLOUDS AT KRDM WILL ALSO GRADUALLY LIFT BY THIS
AFTERNOON WITH CEILINGS IMPROVING TO VFR. ELSEWHERE...VFR CONDITIONS
WITH CLEARING SKIES WILL CONTINUE THROUGH THE DAY. WINDS WILL BE
LESS THAN 10 MPH ACROSS THE REGION FOR THE NEXT 24 HOURS. PATCHY FOG
WILL BE POSSIBLE AT KRDM...KPSC AND KDLS WEDNESDAY MORNING...THOUGH
MVFR TO IFR CONDITIONS ARE NOT ANTICIPATED TO BE AS WIDESPREAD AS
DRIER AIR FILTERS INTO THE REGION. DMH
&&
.PREV DISCUSSION... /ISSUED 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
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 38 26 40 20 / 10 0 0 0
ALW 41 26 40 22 / 10 0 0 0
PSC 43 23 38 23 / 0 0 0 0
YKM 41 23 39 21 / 0 0 0 0
HRI 41 21 37 20 / 10 0 0 0
ELN 45 22 40 19 / 0 0 0 0
RDM 39 13 42 18 / 0 0 0 0
LGD 41 18 38 15 / 10 0 0 0
GCD 39 21 41 23 / 10 0 0 0
DLS 46 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
$$
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