Weather Service Report


119 
FXUS66 KPDT 301151 AAA
AFDPDT

AREA FORECAST DISCUSSION...UPDATED 
NATIONAL WEATHER SERVICE PENDLETON OR 
351 AM PDT SAT MAY 30 2015

UPDATED AVIATION DISCUSSION

.SHORT TERM...TODAY THROUGH MONDAY...AN UPPER RIDGE WILL KEEP 
TEMPERATURES VERY WARM THROUGH THE SHORT TERM PERIOD. HOWEVER...THE 
MAIN CONCERN OVER THE NEXT FEW DAYS WILL BE AFTERNOON AND EVENING 
INSTABILITY WITH WIDESPREAD AREAS OF NEGATIVE LI'S...CAPE AND SHEAR. 
TODAY THE BEST SHEAR AND INSTABILITY WILL BE OVER THE HIGH TERRAIN 
FROM THE BLUE MOUNTAINS SOUTH AND EASTWARD. WILL HAVE A CHANCE OF 
SHOWERS AND AFTERNOON AND EVENING THUNDERSTORMS TODAY AS A RESULT 
WITH A SOUTHWEST FLOW ALOFT AND 45-50 KTS OF SHEAR. THE UPPER RIDGE 
AXIS WILL MOVE TO THE EAST ALLOWING A SOUTHERLY FLOW TO INCREASE. 
THERE WILL BE A DECENT AMOUNT OF SHEAR OF 45-50 KTS ALONG WITH CAPE 
AND NEGATIVE LI'S. WILL AVE A CHANCE OF SHOWERS AND AFTERNOON AND 
EVENING THUNDERSTORMS AGAIN ON SUNDAY IN MUCH THE SAME AREAS AS 
TODAY...I.E. FROM THE BLUE MOUNTAINS AND NORTH CENTRAL OREGON SOUTH 
AND EASTWARD. THUNDERSTORMS MAY PERSIST OVERNIGHT SUNDAY INTO MONDAY 
AS THE ATMOSPHERE REMAINS UNSTABLE OVERNIGHT. MONDAY LOOKS TO BE THE 
BEST DAY OVERALL FOR THUNDERSTORMS WITH THE GREATEST AMOUNT OF 
SHEAR, NEGATIVE LI'S AND CAPE. HOWEVER THE SHEAR IS EXPECTED TO 
DECREASE IN THE AFTERNOON WHICH MAY HELP TO INHIBIT ORGANIZED 
THUNDERSTORMS. HOWEVER MONDAY COULD STILL HAVE THE MOST AND THE 
STRONGEST STORMS WITH SOME POSSIBLY EVEN SEVERE DUE TO A POTENT LOW 
PRESSURE SYSTEM ALOFT ON THE OREGON COAST AND A DEEP SOUTHERLY FLOW 
ALOFT OVER THE CWA. TEMPERATURES THROUGH THE NEXT FEW DAYS WILL BE 
IN THE 80S TO AROUND 90 IN THE LOWER ELEVATIONS WITH 70S TO LOWER 
80S IN THE MOUNTAINS EACH DAY THROUGH MONDAY. LOW LEVEL WESTERLY 
WINDS WILL INCREASE MONDAY AFTERNOON IN THE LOWER COLUMBIA BASIN 
WHICH ALSO MAY HELP TO INHIBIT ORGANIZED STORMS...AS DRIER AND MORE 
STABLE AIR MOVES IN FROM THE WEST OF THE CASCADES IN THE AFTERNOON. 
AS A RESULT THE STRONGEST STORMS MAY BE IN THE MORNING...DECREASING 
IN THE AFTERNOON MONDAY. ELSEWHERE WINDS WILL BE LIGHT THROUGH THE 
SHORT TERM PERIOD. 88 

.LONG TERM...MONDAY NIGHT THROUGH FRIDAY...THE MONDAY SYSTEM IS 
EXPECTED TO CONTINUE TO SWING THROUGH THE REGION MONDAY NIGHT AND 
TUESDAY. FAIRLY WIDE COVERAGE OF ISOLATED TO SCATTERED THUNDERSTORMS 
SHOULD CONTINUE INTO MONDAY EVENING. OVERNIGHT MONDAY THROUGH 
TUESDAY SHOULD SEE A GRADUAL DECREASE IN SHOWERS COVERAGE, 
ESPECIALLY ACROSS THE COLUMBIA BASIN. EXPECTED THUNDERSTORMS TUESDAY 
AFTERNOON AND EVENING SHOULD BE LIMITED TO OUR EASTERN MOST MOUNTAIN 
ZONES. WEAK WAVES LOOK MOVE INTO THE REGION WEDNESDAY THROUGH FRIDAY. 
AT THIS TIME THE LOW LEVEL FLOW LOOKS TO REMAIN WESTERLY AND 
SOMEWHAT STABLE. THUS WILL SEE SHOWERS MAINLY NEAR THE CASCADE CREST 
AND OVER OUR EASTERN ZONES. THUNDERSTORMS LOOK TO BE EVEN MORE 
LIMITED, MAINLY OVER WALLOWA COUNTY AND/OR THE BLUE MOUNTAINS, 
DEPENDING ON THE DAY. 90 

&&

.AVIATION...12Z TAFS...VFR CONDITIONS MAINLY EXPECTED THROUGH THIS 
PERIOD. AREAS OF CIGS 11000 TO 15000 AGL TO MOVE ACROSS CENTRAL AND 
NORTHEAST OREGON AFFECTING KBDN, KRDM, KPDT, KALW AND KPSC. EXPECT 
MAINLY SCT CLOUDS AT KDLS AND KYKM. ISOLATED TO SCATTERED SHOWERS 
AND ISOLATED THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER CENTRAL 
OREGON AND THE BLUE MOUNTAINS THIS AFTERNOON. AT THIS TIME EXPECT 
SHOWERS/STORMS TO STAY EAST OF KPDT AND KALW. A FEW SHOWERS OR A 
STRAY STORM MAY AFFECT KBDN AND KRDM. AT THIS TIME CONFIDENCE IS LOW 
AND WILL NOT MENTION ANY THUNDERSTORMS AT THESE TWO SITES, WILL 
INDICATE VICINITY SHOWERS AT KBDN THOUGH. SUSTAINED WILL WILL RUN 5 
TO 15 KTS WITH STRONGEST WINDS AT KDLS. 90 

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  85  56  85  59 /  10  10  10  20 
ALW  88  60  87  62 /  10  10  10  20 
PSC  91  57  90  62 /  10  10  10  20 
YKM  87  56  86  59 /  10   0  10  20 
HRI  90  58  89  61 /  10  10  10  20 
ELN  84  53  85  57 /  10   0  10  20 
RDM  83  46  83  53 /  20  20  30  40 
LGD  82  51  83  55 /  30  30  20  30 
GCD  84  50  88  49 /  30  30  20  30 
DLS  87  57  88  61 /  10  10  10  30 

&&

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

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

$$

88/90/90

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