Area Forecast Discussion
Issued by NWS Pendleton, OR

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FXUS66 KPDT 200948
AFDPDT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
148 AM PST SAT DEC 20 2014

.SHORT TERM...TODAY THROUGH SUNDAY NIGHT...A VERY ACTIVE PERIOD IS
IN STORE FOR THE FORECAST AREA TODAY THROUGH SUNDAY. A STRONG
PACIFIC STORM SYSTEM WILL MOVE INTO THE NORTHWEST...RIDING ON A
150KT JET STREAM. THIS SYSTEM CONTAINS AN ABUNDANCE OF MOISTURE AND
WIND WHICH IS HEADED FOR THE CWA. SNOW LEVELS WILL BEGIN AROUND 2500
FEET ALONG THE CENTRAL WASHINGTON CASCADE EAST SLOPES THROUGH MID
DAY TODAY. A WINTER WEATHER ADVISORY IS IN EFFECT FOR THE WASHINGTON
CASCADE EAST SLOPES IN WESTERN KITTITAS COUNTY UNTIL 4 PM TODAY.
AFTER THAT SNOW LEVELS WILL TAKE A JUMP UP TO AROUND 6000-7000 FEET
THERE...AND UP TO 7000-8000 FEET OVER OREGON. ELSEWHERE IN THE
FORECAST AREA THIS LOOKS LIKE PRIMARILY A RAIN EVENT. RAIN WILL
BEGIN THIS MORNING AND CONTINUE TONIGHT INTO SUNDAY. RAIN WILL BE
HEAVY AT TIMES...ESPECIALLY IN THE CASCADES AND IN THE NORTHEAST
OREGON MOUNTAINS. RAINFALL AMOUNTS OF 3 TO 6 INCHES ARE POSSIBLE
NEAR THE CASCADE CREST AND 2 TO 4 INCHES OVER THE NORTHEAST
OREGON/SOUTHEAST WASHINGTON MOUNTAINS. NUMEROUS AREAL FLOOD WATCHES
ARE IN EFFECT FROM THIS AFTERNOON THROUGH MONDAY AFTERNOON ACROSS
THE CWA. A MAIN STEM FLOOD WATCH IS ALSO IN EFFECT FOR THE NACHES
RIVER AT NACHES AND THE DESCHUTES RIVER NEAR MOODY RIVER FORECAST
POINTS. THE OTHER CONCERN WITH THIS SYSTEM WILL BE THE STRONG WINDS
ASSOCIATED WITH A STRONG LOW TO MID LEVEL JET STREAM AND A MOUNTAIN
WAVE EFFECT. THESE HIGH WINDS WILL MIX DOWN TO THE SURFACE IN A
MOUNTAIN WAVE EFFECT FROM STRONG WEST WINDS MOVING OVER THE CASCADES
INTO EASTERN OREGON AND WASHINGTON. WIND ADVISORIES WILL BE IN
EFFECT FROM NOON TODAY THROUGH NOON SUNDAY FOR THE YAKIMA
VALLEY...THE LOWER COLUMBIA BASIN OF OREGON/WASHINGTON AND THE BLUE
MOUNTAIN FOOTHILLS OF OREGON/WASHINGTON. HIGH WIND WARNINGS WILL BE
IN EFFECT FOR THE FOOTHILLS OF THE SOUTHERN BLUE MOUNTAINS...THE
SIMCOE HIGHLANDS...NORTH CENTRAL OREGON AND CENTRAL OREGON FROM NOON
TODAY THROUGH NOON ON SUNDAY. THE STRONGEST WINDS WILL OCCUR TONIGHT
BETWEEN 09Z AND 12Z SUNDAY MORNING...AND THEN WILL DECREASE BY
SUNDAY MID DAY. TEMPERATURES WILL ALSO BECOME QUITE MILD FOR THE
TIME OF YEAR WITH MAXIMUM READINGS IN THE MID 40S TO MID 50S BY
SUNDAY AFTERNOON AREA WIDE. 88

.LONG TERM...AN UPPER LEVEL RIDGE WILL BE OVER THE REGION MONDAY
INTO EARLY WEDNESDAY WITH MOSTLY DRY WEATHER AND A CHANCE OF VALLEY
FOG. A STORM SYSTEM WILL MOVE ACROSS THE REGION ON WEDNESDAY INTO
THURSDAY WITH A CHANCE OF RAIN AND MOUNTAIN SNOW. THE GFS HAS SLOWED
THIS SYSTEM DOWN A BIT WITH THE ECMWF ABOUT 12 HRS FASTER. BOTH
MODELS HAVE REDUCED THE ARCTIC AIR INTRUSION ASSOCIATED WITH THE
STORM. HOWEVER IT WILL STILL BE TURNING COLDER BY CHRISTMAS DAY BUT
ALSO DRIER. THERE COULD BE SOME TRAVEL IMPACTS WEDNESDAY SO THE
FORECAST WILL HAVE TO BE MONITORED IN THE COMING DAYS. 78

&&

.AVIATION...12Z TAFS...WIDESPREAD RAIN IS EXPECTED TODAY WITH MOSTLY
MFR CIGS/VSBYS DUE TO THE PRECIPITATION AND BR. RAIN WILL TAPER
SOMEWHAT OVERNIGHT BUT WINDS WILL INCREASE ESPECIALLY AFTER 06Z.
WINDS COULD REACH 20-30KT WITH GUSTS TO 45KT FROM THE WSW AT
KPDT...KALW...KRDM...AND KBDN. 78

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  52  46  57  39 /  90  90  80  50
ALW  51  44  56  39 /  90 100  90  60
PSC  49  42  55  39 /  90  80  40  10
YKM  43  35  50  34 /  90  80  40  20
HRI  51  43  56  41 /  90  80  50  20
ELN  42  33  46  32 /  90 100  60  20
RDM  49  41  53  40 /  90  80  70  20
LGD  43  39  47  38 /  90 100 100  80
GCD  43  41  46  41 /  90 100  80  60
DLS  49  43  52  41 /  90 100  90  40

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...HIGH WIND WARNING FROM NOON TODAY TO NOON PST SUNDAY ORZ510-511.

     FLOOD WATCH FROM THIS AFTERNOON THROUGH MONDAY AFTERNOON
     ORZ041-509>511.

     FLOOD WATCH FROM THIS AFTERNOON THROUGH MONDAY AFTERNOON
     ORZ049-050-502-503-505>508.

     WIND ADVISORY FROM NOON TODAY TO NOON PST SUNDAY ORZ044.

     WIND ADVISORY FROM NOON TODAY TO NOON PST SUNDAY ORZ507.

     HIGH WIND WARNING FROM NOON TODAY TO NOON PST SUNDAY ORZ508.

WA...FLOOD WATCH FROM THIS AFTERNOON THROUGH MONDAY AFTERNOON
     WAZ024-026-027-520-521.

     FLOOD WATCH FROM THIS AFTERNOON THROUGH MONDAY AFTERNOON
     WAZ029-030.

     WIND ADVISORY FROM NOON TODAY TO NOON PST SUNDAY WAZ028.

     HIGH WIND WARNING FROM NOON TODAY TO NOON PST SUNDAY WAZ521.

     WIND ADVISORY FROM NOON TODAY TO NOON PST SUNDAY WAZ029.

     WIND ADVISORY FROM NOON TODAY TO NOON PST SUNDAY WAZ027.

     WINTER WEATHER ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR
     WESTERN KITTITAS COUNTY IN THE WAZ520.

&&

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

$$

88/78/78





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