Severe Thunderstorm Warning 23, NWS Pendleton, OR

NORTHEAST OREGON/SOUTHEAST WASHINGTON FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
230 PM PDT SUN JUL 14 2002

SATELLITE PICTURES SHOW BUILD UPS AND A FEW THUNDERSTORMS FORMING
OVER SOUTHEAST OREGON.  THESE ARE FORMING AHEAD OF COOL FRONT THAT
IS STALLING OVER THE BLUE MOUNTAINS.  THIS WILL ALLOW MOISTURE TO
LINGER OVER THE MOUNTAINS OF NORTHEAST OREGON FOR THE NEXT SEVERAL
DAYS.  UPPER TROUGH REMAINS ALONG THE WEST COAST WITH SOUTHWEST FLOW
OVER THE OREGON PORTION OF FORECAST AREA.  THIS SOUTHWEST FLOW WILL
ALLOW SEVERAL DISTURBANCE TO MOVE OVER THE MOUNTAINS AND INTERACT
WITH MOISTURE AND DAYTIME HEAT TO PRODUCE ISOLATED THUNDERSTORMS
THROUGH TUESDAY.  ON WEDNESDAY...A WEAK SHORTWAVE WILL MOVE
NORTHEAST OVER THE REGION AND BRING ANOTHER PUSH OF MOISTURE...BUT
IT APPEARS VERY LIMITED.  SO WILL ONLY HAVE A SLIGHT CHANCE OF
THUNDERSTORMS OVER MOUNTAINS.  TEMPERATURES TO WARM A FEW DEGREES
EACH DAY. LOHMANN

EXTENDED...ZONAL FLOW ALOFT AND DRY AIR WILL PREVENT ANY SIGNIFICANT
PRECIPITATION FROM FALLING THROUGH SATURDAY. PORTIONS OF CENTRAL
WASHINGTON WILL GRADUALLY SEE AN INCREASE IN CLOUD COVER BEGINNING
FRIDAY AS ANOTHER...WEAK LOW PRESSURE AREA APPROACHES THE COAST OF
SOUTHEASTERN ALASKA. AS THE LOW APPROACHES...IT WILL INDUCE A
SOUTHWESTERLY SLIGHT SOUTHWESTERLY FLOW OVER THE NORTHWEST ON
SUNDAY. THIS...COUPLED WITH AN APPROACHING MARINE PUSH WILL INDUCE
INSTABILITY OVER THE NORTHEAST MOUNTAINS AND ENOUGH MOISTURE IS
EXPECTED FOR ISOLATED AFTERNOON THUNDERSTORMS. MODEL TIMING OF THIS
PUSH SEEMS REASONABLE BASED ON THE FREQUENCY OF RECENT MARINE
PUSHES. HENRY

PDT 11--  ALW 11--  PSC 1000  YKM 0000

KPDT...VCP21/CSR21...OPERATIONAL.

.KPDT...NONE.