680 
FXUS66 KPQR 060952
AFDPQR

NORTHWEST OREGON AND SOUTHWEST WASHINGTON FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
300 AM PDT WED AUG 6 2003

.SYNOPSIS...AN UPPER LEVEL LOW IS LIFTING NE ACROSS WESTERN WA THIS
MORNING AS IT WEAKENS. A TROUGH OF LOW PRESSURE WILL REMAIN OFFSHORE
THROUGH THE WEEK KEEPING A THREAT OF SHOWERS OVER THE FORECAST
AREA...MAINLY TO COASTAL AREAS.

.DISCUSSION...
.SHORT TERM...SATELLITE WATER VAPOR LOOP SHOWS THE UPPER LEVEL LOW
OVER WESTERN WA THIS MORNING LIFTING SLOWLY NORTH...AS DEPICTED BY
THE 06Z MESO ETA AND 00Z GFS. IR SATELLITE AND RADAR INDICATE LAST
OF SHOWERS ARE EXITING THE SOUTHWEST WA AREA OF THE CWA...MOVING NNE.
WILL TAKE SHOWER/TSTM THREAT OUT OF CWA FOR 4 AM FORECAST. METARS AND
SATELLITE SHOW AREAS LOW CLOUDS FORMING OVER THE NORTH AND EAST
WILLAMETTE VALLEY.

00Z GFE AND 06Z MESO ETA BOTH SHOW A LITTLE MORE INSTABILITY OVER THE
CASCADES THIS AFTERNOON AND FURTHER NORTH...WILL A CHANCE OF THUNDER
OVER THE SOUTHERN WA/OREGON CASCADES THIS AFTERNOON AND EVENING AS
ANOTHER SHORT WAVE ABOUT TO BOTTOM OUT NEAR 40N SWINGS AROUND AND
LIFTS NORTHEAST INTO OREGON.

THU INTO FRI WOBBLY LOW OFFSHORE MAY PUSH SOME SHOWER ACTIVITY
ONSHORE WITH A WEAK SHORTWAVE LIFTING THROUGH THU NIGHT AND EARLY
FRI. WILL KEEP A CHANCE OF SHOWERS GOING ALONG THE COAST AND NORTH
INTERIOR FOR THU NIGHT AND FRI MORNING. LIKENS

.LONG TERM...NEW GFE VEERS AWAY FROM SOLUTIONS ON PREVIOUS RUNS AND
FROM OTHER MODELS. MODELS WERE GENERALLY CONSISTENT IN LEAVING THE
UPPER LEVEL TROUGH OFF THE COAST THROUGH THE EXTENDED PERIOD...AND
FORECASTS WERE WRITTEN WITH THIS SOLUTION IN MIND. NEW GFE EJECTS LOW
NORTHEAST SAT NIGHT AND MOVES THE TROUGH INLAND MON. WILL LEAVE
FORECASTS UNCHANGED AT THIS TIME...IN FAVOR OF WAITING UNTIL THERE IS
MORE MODEL CONTINUITY.

AST 11233 PDX 11122 SLE 11111 EUG 11111

.PQR...NONE.
$$