Hazardous Weather Outlook

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
540 AM PDT WED JUN 23 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL AND NORTHEAST OREGON
AS WELL AS SOUTH CENTRAL AND SOUTHEAST WASHINGTON.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS
EAST SLOPES OF THE CENTRAL CASCADES OF WASHINGTON, EAST SLOPES
OF THE SOUTHERN CASCADES OF WASHINGTON, EASTERN COLUMBIA RIVER
GORGE OF WASHINGTON, KITTITAS VALLEY, YAKIMA VALLEY, LOWER
COLUMBIA BASIN OF WASHINGTON, FOOTHILLS OF THE BLUE MOUNTAINS
OF WASHINGTON, NORTHWEST BLUE MOUNTAINS OF WASHINGTON, EASTERN
COLUMBIA RIVER GORGE OF OREGON, NORTH CENTRAL OREGON, CENTRAL
OREGON, LOWER COLUMBIA BASIN OF OREGON, GRANDE RONDE VALLEY,
WALLOWA COUNTY, FOOTHILLS OF THE BLUE MOUNTAINS OF OREGON,
NORTHERN BLUE MOUNTAINS OF OREGON, SOUTHERN BLUE MOUNTAINS OF
OREGON, NORTHERN WHEELER AND SOUTHERN GILLIAM COUNTIES, JOHN
DAY BASIN, OCHOCO-JOHN DAY HIGHLANDS

A WEAK DISTURBANCE WILL MOVE THROUGH THE REGION THIS MORNING. THIS
SYSTEM WILL BRING MOSTLY CLOUDY SKIES AND POTENTIALLY A SPRINKLE OR
TWO. AN UPPER TROUGH WILL MOVE ONSHORE THIS AFTERNOON AND TONIGHT.
THIS TROUGH WILL CAUSE THE AIR MASS TO DESTABILIZE IN THE AFTERNOON
ALLOWING FOR THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS OVER MUCH OF THE AREA. THESE STORMS MAY PRODUCE BRIEF HEAVY RAIN...SMALL HAIL
AND GUSTY WINDS. THE THUNDERSTORMS SHOULD END BY MIDNIGHT...BUT A
FEW SHOWERS MAY LINGER THROUGH THE NIGHT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THUNDERSTORMS THURSDAY
LOWER COLUMBIA BASIN OF WASHINGTON, FOOTHILLS OF THE BLUE
MOUNTAINS OF WASHINGTON, NORTHWEST BLUE MOUNTAINS OF
WASHINGTON, CENTRAL OREGON, LOWER COLUMBIA BASIN OF OREGON,
GRANDE RONDE VALLEY, WALLOWA COUNTY, FOOTHILLS OF THE BLUE
MOUNTAINS OF OREGON, NORTHERN BLUE MOUNTAINS OF OREGON,
SOUTHERN BLUE MOUNTAINS OF OREGON, NORTHERN WHEELER AND
SOUTHERN GILLIAM COUNTIES, JOHN DAY BASIN, OCHOCO-JOHN DAY
HIGHLANDS

THE UPPER TROUGH WILL WEAKEN THURSDAY INTO FRIDAY. THIS WILL ALLOW
FOR GRADUALLY INCREASING ONSHORE FLOW. THERE SHOULD BE ENOUGH
INSTABILITY THURSDAY FOR MORE SHOWERS AND THUNDERSTORMS...THOUGH
THIS THREAT SHOULD BE LIMITED IN CENTRAL WASHINGTON AND CENTRAL
OREGON. THE BEST CHANCES FOR THUNDERSTORMS WILL BE OVER THE EXTREME
NORTHEAST OREGON THURSDAY. THE COVERAGE OF SHOWERS AND THE THREAT OF THUNDERSTORMS WILL DIMINISH FURTHER ON FRIDAY. WEAK HIGH PRESSURE SHOULD BRING DRIER AND WARMER CONDITIONS TO THE REGION THIS WEEKEND. ANOTHER DEEP PACIFIC LOW PRESSURE SYSTEM LOOKS TO PUSH A COLD FRONT INTO THE REGION EARLY NEXT WEEK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED.

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

GRAPHICAL FORECASTS OF WEATHER HAZARDS OUT TO SEVEN DAYS
ARE DISPLAYED ON THE WORLD WIDE WEB AT:

WWW.WRH.NOAA.GOV/PDT/CURRENTHAZARDS/HWO.HTML