Area Forecast Discussion
Issued by NWS Pendleton, OR

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FXUS66 KPDT 251631
AFDPDT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
831 AM PST SUN JAN 25 2015

.SHORT TERM...TODAY THROUGH MONDAY...A LARGE RIDGE OF HIGH PRESSURE
WILL REMAIN OVER THE REGION. THESE WILL BRING VERY WARM TEMPERATURES
TO MOST OF THE FORECAST AREA TODAY AND MONDAY...POSSIBLE RECORD
SETTING WARMTH. HOWEVER...AN INVERSION HAS BEGUN TO DEVELOP IN THE
LOWER COLUMBIA BASIN IN WHICH LOW CLOUDS AND FOG HAVE DEVELOPED.
AREAS WHERE THIS IS OCCURRING WILL NOT SEE THE VERY WARM
TEMPERATURES DUE TO THE COOLER AIR BEING TRAPPED BENEATH THE
INVERSION AND LACK OF SUNSHINE TO WARM TEMPERATURES UP. OTHER
CONCERN WILL BE THE VERY WINDY CONDITIONS IN THE SOUTHERN GRANDE
RONDE VALLEY. WIND ADVISORY HAS BEEN ISSUED THROUGH MONDAY
AFTERNOON.



&&

.PREV DISC... /ISSUED 543 AM PST SUN JAN 25 2015/

SHORT TERM...TODAY THROUGH TUESDAY. STRONG UPPER LEVEL RIDGE OVER
THE AREA TODAY. VERY WARM TEMPERATURES AT 850MB. WILL RESULT IN HIGH
TEMPS IN THE 60S WITH POSSIBLE LOWER 70S. EXCEPTION TO THIS WILL BE
THE COLUMBIA BASIN AND ADJACENT VALLEYS WHERE FOG IS CURRENTLY
DEVELOPING. EXTENT OF FOG IMPLIES A DECENT LOW LEVEL INVERSION OVER
THE BASIN WHICH WILL KEEP TEMPS DOWN. WILL GO WITH HIGHS IN THE 40S
AND 50S FOR THESE LOCATIONS. SATELLITE SHOW A LITTLE CIRRUS WILL BE
MOVING THROUGH DURING THE DAY OTHERWISE MOSTLY SUNNY SKIES. WINDY IN
THE GRANDE RONDE VALLEY WHICH WILL CONTINUE THROUGH MONDAY. HAVE
ISSUED A WIND ADVISORY FOR THIS. THE UPPER RIDGE HOLDS IN PLACE
MONDAY WITH ANOTHER MOSTLY SUNNY AND WARM DAY. ALTHOUGH NOT QUITE AS
WARM AS TODAY. 850MB TEMPS ARE STARTING TO FALL AT THIS POINT.
EXPECT AREAS OF LOW CLOUDS AND FOG AGAIN IN THE COLUMBIA BASIN AND
ADJACENT VALLEYS WITH COOLER TEMPS. SURFACE GRADIENTS MAINTAIN WINDY
CONDITIONS IN THE GRANDE RONDE VALLEY. THE RIDGE MOVES OFF TO THE
EAST TUESDAY ALLOWING A WEATHER SYSTEM TO APPROACH THE REGION. CLOUDS
WILL BE INCREASING WITH COOLER TEMPS. 94

LONG TERM...TUESDAY NIGHT THROUGH SATURDAY.  A MID/HIGH LEVEL RIDGE
OF HIGH PRESSURE WILL HOLD SWAY OVER THE INTERIOR PACIFIC NORTHWEST
THROUGHOUT THE PERIOD FOR MAINLY DRY CONDITIONS. A WEAK MID/UPPER
LEVEL PACIFIC SHORT WAVE MOVES THROUGH THE RIDGE TUESDAY NIGHT AND
WEDNESDAY WITH THE BEST CHANCE FOR MEASURABLE RAIN IN THE BLUE
MOUNTAINS FROM AROUND MIDNIGHT THROUGH WEDNESDAY AFTERNOON. SNOW
LEVELS WITH THIS SYSTEM WILL BE 6000-6500 FEET TUESDAY NIGHT AND
WEDNESDAY. AS SUCH THE HIGHEST MOUNTAINS ABOVE 6500 FEET WILL GET
SOME LIGHT SNOW TUESDAY NIGHT AND WEDNESDAY. THE RIDGE BUILDS BACK
AGAIN WEDNESDAY NIGHT THROUGH SATURDAY FOR DRY CONDITIONS.  POLAN

AVIATION...12Z TAFS...MAINLY VFR CONDITIONS WILL OCCUR TODAY AND
TONIGHT, EXCEPT AT KYKM AND KDLS, WHERE LOWER CIGS AND/OR REDUCED
VISIBILITY DUE TO AREAS OF SHALLOW GROUND FOG MAY CAUSE LIFR/VLIFR
CONDITIONS AT TIMES THIS MORNING. CONDITIONS AT KYKM AND KDLS WILL
IMPROVE TO VFR BY 20Z TODAY. KALW AND KPDT WILL HAVE DOWNSLOPE WINDS
DUE TO DRAINAGE WINDS FROM THE BLUE MOUNTAINS, WHICH WILL MIX OUT
THE BOUNDARY LAYER AND PRODUCE VFR CONDITIONS THROUGH THE NEXT 24
HOURS. WINDS WILL BE NEAR CALM OR LIGHT AND VARIABLE FOR THE NEXT 24
HOURS AT ALL TAF SITES.  POLAN

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  62  44  56  36 /   0   0   0   0
ALW  52  37  58  38 /   0   0   0   0
PSC  44  34  48  35 /   0   0   0   0
YKM  47  32  47  33 /   0   0   0   0
HRI  55  34  51  35 /   0   0   0   0
ELN  48  37  49  32 /   0   0   0   0
RDM  68  42  63  35 /   0   0   0   0
LGD  49  37  50  34 /   0   0   0   0
GCD  60  37  58  31 /   0   0   0   0
DLS  57  44  56  39 /   0   0   0   0

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING ORZ041.

     WIND ADVISORY UNTIL 3 PM PST MONDAY ORZ049.

WA...DENSE FOG ADVISORY UNTIL 10 AM PST THIS MORNING WAZ024-026-027.

&&

FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT...
WWW.WEATHER.GOV/PENDLETON

$$

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