777 
FXUS66 KPDT 190903
AFDPDT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
203 AM PDT TUE MAR 19 2013

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...A WARM FRONT WILL MOVE 
INTO CENTRAL OREGON TODAY AND SPREAD PRECIPITATION NORTH AND EAST 
ACROSS THE CWA THIS AFTERNOON. THE PRECIPITATION WILL BE PRIMARILY 
RAIN AS SNOW LEVELS WILL RISE TO 5000-6000 FEET BY THIS EVENING. 
BREEZY SOUTHERLY WINDS WILL DEVELOP TONIGHT, PARTICULARLY IN THE 
SOUTHERN GRANDE RONDE VALLEY. A STRONG COLD FRONT WILL MOVE THROUGH 
THE AREA WEDNESDAY AFTERNOON AND EVENING. THIS WILL KEEP 
PRECIPITATION OVER THE AREA. RAIN SHADOWING WILL DEVELOP OVER THE 
LOWER COLUMBIA BASIN AND DESCHUTES PLATEAU, BUT OROGRAPHIC EFFECTS 
WILL KEEP POPS HIGH IN THE MOUNTAINS. WINDS WILL BE WINDY TO LOCALLY 
VERY WINDY BEHIND THE COLD FRONT...ESPECIALLY IN THE COLUMBIA BASIN 
AND THE FOOTHILLS OF THE BLUE MOUNTAINS. THE UPPER TROUGH SUPPORTING 
THE FRONT WILL MOVE EAST WEDNESDAY NIGHT WITH DECREASING 
PRECIPITATION.  COONFIELD

.LONG TERM...THURSDAY THROUGH MONDAY NIGHT...MODELS ARE BEGINNING TO 
AGREE WITH A TROUGH OF LOW PRESSURE DROPPING ACROSS THE PACIFIC 
NORTHWEST FROM THE NORTH THURSDAY INTO FRIDAY. THIS WILL KEEP 
TEMPERATURES BELOW NORMAL AND SNOW LEVELS WILL REMAIN AROUND 
2000-3000 FEET. WITH SOME MOISTURE AND AN UPSLOPE FLOW...THERE WILL 
REMAIN A CHANCE OF PRECIPITATION IN THE AREA MOUNTAINS THROUGH 
FRIDAY. MODELS BEGIN TO DIVERGE SATURDAY INTO NEXT WEEK WITH THE GFS 
SHIFTING THE TROUGH OVER THE ROCKY MOUNTAINS AND LEAVING THE PACIFIC 
NORTHWEST IN A NORTH FLOW. THE EUROPEAN MODEL MOVES THE TROUGH 
EASTWARD WITH A RIDGE BUILDING INTO THE REGION. HAVE LEANED TOWARD 
THE GFS AS IT HAS HAD THE BETTER CONSISTENCY OVER THE LAST FEW DAYS. 
WITH THE NORTHERLY FLOW...SOME DISTURBANCES MOVING THROUGH IT WILL 
KEEP A CHANCE OF PRECIPITATION OVER THE AREA THROUGH SUNDAY. SUNDAY 
NIGHT INTO MONDAY...THE GFS BUILDS THE RIDGE OF HIGH PRESSURE OFF 
SHORE...PUSHING THE TROUGH FURTHER EAST AND LEADING TO A DRYING AND 
WARMING TREND. DMH


&&

.AVIATION...PREVIOUS DISCUSSION...06Z TAFS...EXPECT VFR CONDITIONS 
TO PREVAIL THROUGH MOST OF THIS PERIOD. CIGS WILL GRADUALLY LOWER 
THROUGH TUESDAY INTO TUESDAY EVENING DUE TO THE APPROACH OF THE NEXT 
PACIFIC SYSTEM. LOWEST CIGS WILL BE BETWEEN 4500 AND 8000 FT AGL 
LATE IN THE PERIOD WITH SHOWERS AT OR IN THE VICINITY OF ALL SITES. 
WINDS WILL MAINLY RUN 10 KTS OR LESS THROUGH THE PERIOD, THOUGH 
GUSTIER WINDS ARE POSSIBLE AT KBDN TUESDAY EVENING. 90 


&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  58  42  60  36 /  10  60  60  30 
ALW  59  45  60  39 /  10  60  60  30 
PSC  57  43  63  42 /  10  60  40  20 
YKM  54  35  58  32 /  20  70  50  20 
HRI  58  41  62  36 /  10  60  40  20 
ELN  55  35  56  32 /  20  70  50  20 
RDM  61  37  54  24 /  50  60  50  20 
LGD  50  44  55  34 /  10  70  70  30 
GCD  59  38  53  28 /  40  70  60  30 
DLS  55  40  56  36 /  40  80  50  20 

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...NONE.
WA...NONE.
&&

THREAT INDEX
TODAY : GREEN
WEDNESDAY : YELLOW
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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