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000
FXUS66 KPDT 201004
AFDPDT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
300 AM PDT THU JUN 20 2013

.SHORT TERM...TODAY THROUGH FRIDAY NIGHT...AN UPPER LOW CONTINUES TO
MOVE THROUGH THE PACIFIC NORTHWEST AND IS LOCATED OVER THE IDAHO
PANHANDLE THIS MORNING. IT WILL MOVE INTO NORTHWESTERN MONTANA THIS
AFTERNOON AND INTO SOUTHERN ALBERTA BY FRIDAY MORNING. CURRENTLY
RADAR IS SHOWING SCATTERED SHOWERS FROM THE TRI-CITIES AND PENDLETON
EASTWARD AND ALSO ALONG THE WASHINGTON CASCADE CREST. ANOTHER BAND
NEAR SPOKANE LOOKS AS IF IT WILL SWING INTO OUR AREA LATER THIS
MORNING AND BRING SHOWERS TO THE EASTERN COLUMBIA BASIN, BLUE
MOUNTAIN FOOTHILLS, THE NORTHERN BLUE MOUNTAINS AND WALLOWA COUNTY.
MOISTURE IS WRAPPING AROUND THE LOW AND SHOULD CONTINUE TO DO SO FOR
THE NEXT 24 HOURS WITH STEADILY DECREASING INTENSITY. HAVE ISOLATED
SHOWERS FOR MOST OF THE AREA THIS MORNING WITH SCATTERED SHOWERS IN
THE EAST WHERE THE NEXT BAND SHOULD ARRIVE SEVERAL HOURS FROM NOW.
WITH DAYTIME HEATING THIS AFTERNOON EXPECT SCATTERED SHOWERS OVER
THE NORTHERN TWO THIRDS OF THE AREA WITH ISOLATED SHOWERS OVER MOST
OF THE REST OF THE AREA. WHILE THE LAST COUPLE OF DAYS HAS NOT HAD
MUCH THUNDERSTORM ACTIVITY, MODELS CONTINUE TO SHOW SOME INSTABILITY
OVER THE EASTERN MOUNTAINS FROM THE BLUE MOUNTAINS INTO WALLOWA
COUNTY AND SOUTHWEST INTO THE OCHOCO-JOHN DAY HIGHLANDS. HAVE
EXPANDED EXISTING SLIGHT CHANCE THUNDERSTORM COVERAGE TO INCLUDE
JOHN DAY, SENECA AND PAULINA. AM NOT EXPECTING MORE THAN A FEW CELLS
WITH A FEW LIGHTNING STRIKES EACH. WINDS WILL BE BREEZY THIS
AFTERNOON WITH 15 TO 25 MPH WINDS IN THE COLUMBIA GORGE AND KITTITAS
VALLEY AND 10 TO 20 MPH IN THE COLUMBIA BASIN AND CENTRAL OREGON.
SHOWER ACTIVITY WILL DIMINISH OVERNIGHT AND HAVE A CHANCE OF SHOWERS
IN THE MOUNTAINS WITH A SLIGHT CHANCE IN THE LOWER ELEVATIONS.
CENTRAL OREGON SHOULD BE DRY. BY FRIDAY AFTERNOON THERE WILL BE A
LINGERING TROUGH OVER THE EASTERN THIRD OF THE AREA WITH THE CENTRAL
LOW IN EASTERN ALBERTA WHILE A RIDGE STARTS TO DEVELOP IN THE
EASTERN PACIFIC. THIS WILL KEEP A NORTHERLY FLOW OVER THE AREA AND
ONE MORE DAY OF A SLIGHT CHANCE OF SHOWERS WITH A SLIGHT CHANCE OF
AFTERNOON THUNDERSTORMS LIMITED TO WALLOWA COUNTY AND THE STRAWBERRY
AND ELKHORN MOUNTAINS. BY FRIDAY EVENING, THE TROUGH WILL BE IN
WESTERN MONTANA AND THE AREA SHOULD GO DRY ASIDE FROM A SLIGHT
CHANCE OF SHOWERS IN THE EASTERN MOUNTAINS AND THE WASHINGTON
CASCADE CREST. TEMPERATURES WILL WARM A COUPLE OF DEGREES TODAY TO
THE MID 60S TO LOWER 70S WITH MID 50S TO LOWER 60S IN THE MOUNTAINS.
TOMORROW TEMPERATURES WILL WARM ANOTHER DEGREE OR TWO. PERRY

.LONG TERM...SATURDAY THROUGH WEDNESDAY...WEAK HIGH PRESSURE WILL BE
OVER THE REGION SATURDAY. THUS EXPECT MOSTLY DRY CONDITIONS WITH
WARMER HIGH TEMPERATURES. THERE MAY BE A FEW SHOWERS OVER THE
NORTHERN BLUE MOUNTAINS AND WALLOWA COUNTY DUE TO LINGERING MOISTURE
FROM THE SYSTEM SLOWLY MOVING THROUGH THE AREA LATE THIS WEEK. FOR
THE PERIOD SUNDAY THROUGH WEDNESDAY, A LOW PRESSURE SYSTEM IS
EXPECTED TO SET UP OVER THE EASTERN PACIFIC. THIS LOW SHOULD SEND A
SERIES OF DISTURBANCE INTO THE PACNW RESULTING IN PERIODS OF
SCATTERED SHOWERS. THERE MAY ALSO BE A FEW THUNDERSTORMS OVER OUR
EASTERN ZONES DURING THE AFTERNOONS AND EVENINGS SUNDAY THROUGH
WEDNESDAY. HIGH TEMPERATURES LOOK TO BE NEAR TO SLIGHTLY BELOW
SEASONAL, WHILE LOW TEMPERATURES LOOK TO RUN NEAR TO SLIGHTLY ABOVE
SEASONAL. 90

&&

.AVIATION...PREVIOUS DISCUSSION...06Z TAFS. WIDESPREAD PRECIPITATION
WILL CONTINUE UNTIL 09Z-12Z FROM THE BLUE MTN FOOTHILLS EAST TO THE
IDAHO BORDER. DESPITE THE -RA AT KPDT AND KALW...CIGS ARE NOT
EXPECTED TO LOWER BELOW 4K FEET AGL. PRECIPITATION WILL TAPER OFF BY
12Z. ELSEWHERE...VARYING CLOUD COVER WITH BASES BETWEEN 6-12K FEET
AGL AND HIGHER CLOUDS ABOVE CAN BE EXPECTED THROUGH THE NIGHT. A
COOL UNSTABLE AIR MASS WILL ALLOW CUMULUS CLOUDS AND SHOWERS TO
DEVELOP THURSDAY AFTERNOON...HOWEVER CONDITIONS ARE EXPECTED TO
REMAIN VFR AT ALL TAF SITES. WINDS WILL GENERALLY RANGE FROM 10-20
KNOTS WITH GUSTS TO 30 KNOTS FOR THE NEXT 24 HOURS...WITH THE
EXCEPTION OF KRDM AND KBDN WHERE 5-15 KNOTS ARE EXPECTED.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  68  48  69  49 /  40  30  30  20
ALW  69  52  70  52 /  40  30  30  20
PSC  72  53  73  52 /  30  30  20  10
YKM  67  50  70  50 /  40  30  30  10
HRI  72  51  73  50 /  30  30  20  10
ELN  64  50  68  49 /  40  30  30  10
RDM  65  39  67  41 /  20  20  10  10
LGD  62  44  62  43 /  30  30  30  30
GCD  62  41  63  42 /  20  20  20  20
DLS  70  53  71  53 /  30  30  20  10

&&

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

THREAT INDEX
TODAY : GREEN
FRIDAY : GREEN
SATURDAY : 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

$$

83/90/90