Hail in Oregon, June 2, 2014

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
300 AM PDT MON JUN 2 2014

.SHORT TERM...TODAY THROUGH TUESDAY NIGHT...A WEAK UPPER TROUGH WILL
DIG OUT OF BRITISH COLUMBIA TODAY, THEN SLOWLY SHIFT ACROSS THE
PACIFIC NORTHWEST TONIGHT AND TUESDAY. AT THE SAME TIME, THIS TROUGH
WILL PULL MOISTURE NORTH INTO THE REGION FROM AN UPPER LOW OVER
CALIFORNIA. THUS WILL SEE ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS DEVELOP THIS AFTERNOON OVER A GOOD PORTION OF THE
AREA. THE BEST CHANCES WILL RUN FROM CENTRAL OREGON EAST TO GRANT
COUNTY AND NORTHEAST TO THE BLUE MOUNTAINS, THE BLUE MOUNTAIN
FOOTHILLS, THE GRANDE RONDE VALLEY AND WALLOWA COUNTY. A FEW SHOWERS
AND/OR STORMS SHOULD DEVELOP OVER THE WASHINGTON CASCADE EAST SLOPES
AS WELL. THERE IS THE POSSIBILITY THAT THESE SHOWERS OR STORMS COULD
DRIFT INTO THE WESTERN PORTIONS OF THE KITTITAS AND YAKIMA VALLEYS
THIS AFTERNOON. THE TROUGH WILL ALSO INCREASE THE ONSHORE FLOW THIS
AFTERNOON. AS SUCH SHOULD SEE STABLE MARINE AIR REACH INTO THE
COLUMBIA RIVER GORGE AND AREAS IMMEDIATELY NORTH AND SOUTH OF THE
GORGE. THUS EXPECT THIS AREA TO STAY DRY AND THUNDER FREE. THE
STABLE MARINE AIR WILL GRADUALLY WORK INLAND TONIGHT AND TUESDAY.
THUS WILL SEE A GRADUAL END TO THE SHOWERS AND STORMS FROM CENTRAL
WASHINGTON SOUTH TO CENTRAL OREGON THIS EVENING. EXPECT TO SEE
LINGERING SHOWERS FROM GRANT COUNTY NORTH INTO THE BLUE MOUNTAINS
AND EAST TO WALLOWA COUNTY FROM LATE TONIGHT THROUGH TUESDAY. BY
LATE TUESDAY AFTERNOON SHOWERS SHOULD BE DONE IN GRANT COUNTY.
MEANWHILE ONLY WALLOWA COUNTY IS EXPECTED TO SEE A ANY CHANCE OF
THUNDERSTORMS TUESDAY. CONDITIONS WILL BE DRY AREAWIDE FROM SUNSET
TUESDAY NIGHT INTO EARLY WEDNESDAY MORNING. BREEZY CONDITIONS ARE
EXPECTED TUESDAY AS THE UPPER TROUGH AXIS PUSHES THROUGH THE REGION.
90

.LONG TERM...WEDNESDAY THROUGH SUNDAY...A DRY WEST-NORTHWEST FLOW
ALOFT WILL HOLD SWAY OVER THE FORECAST AREA THROUGH THURSDAY NIGHT
FOR DRY AND STABLE CONDITIONS. THEN A LOW AMPLITUDE MID/UPPER LEVEL
TROUGH ENTERS THE PICTURE DURING THE DAY ON FRIDAY, WHICH WILL
INTRODUCE A SLIGHT CHANCE OF SHOWERS AND A FEW STRAY THUNDERSTORMS
FRIDAY AFTERNOON/EVENING OVER THE NORTHEAST MOUNTAINS OF OREGON AND
WASHINGTON. WITH A MID/UPPER LEVEL RIDGE OF HIGH PRESSURE ENTRENCHED
OVER THE NORTHEAST PACIFIC THROUGH THE WEEKEND, A DRY WEST-NORTHWEST
FLOW ALOFT RE-ESTABLISHES ITSELF ACROSS THE PACIFIC NORTHWEST FRIDAY
NIGHT AND PERSISTS OVER THE REGION THROUGH SUNDAY FOR DRY AND STABLE
CONDITIONS. ON SATURDAY AND SUNDAY THE 00Z ECMWF RUN SHOWS A PACIFIC
TROUGH MOVING INTO THE FORECAST AREA, WHEREAS THE 00Z GFS RUN KEEPS
A FLAT RIDGE OVER THE REGION. THUS KEPT REGION DRY THROUGH THE
WEEKEND.  POLAN

&&

.AVIATION...12Z TAFS...VFR CONDITIONS EXPECTED OVER THE NEXT 24
HOURS. THERE WILL BE SOME POTENTIAL FOR THUNDERSTORM DEVELOPMENT
OVER THE MOUNTAINS MONDAY AFTERNOON/EVENING WHICH COULD GET INTO THE
VICINITY OF SOME SITES SO WILL NEED TO MONITOR THIS AS CONDITIONS
UNFOLD MONDAY.

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  86  54  81  47 /  20  20  10  10
ALW  86  60  82  54 /  20  20  10  10
PSC  89  55  86  50 /  10  10  10  10
YKM  86  53  81  48 /  20  10   0   0
HRI  88  54  84  47 /  20  10  10   0
ELN  86  55  78  51 /  20  10  10   0
RDM  83  43  78  34 /  30  20  10   0
LGD  82  51  77  41 /  30  30  20  10
GCD  85  47  80  40 /  30  30  20  10
DLS  84  56  78  51 /  10  10   0   0

&&

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

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

90/99/99