000 
FXUS66 KPQR 041600
AFDPQR

NORTHWEST OREGON AND SOUTHWEST WASHINGTON FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
900 AM PDT THU SEP 4 2003

.SYNOPSIS...A RIDGE OF HIGH PRESSURE OVER THE WESTERN U.S. WILL
LINGER THROUGH THE END OF THE WEEK AS IT FLATTENS AND DRIFTS EAST. A
FEW WEAK UPPER DISTURBANCES WILL MOVE NORTHEAST THROUGH THE FORECAST
AREA TODAY AND FRIDAY AND POSSIBLY PRODUCE SOME CONVECTION NEAR THE
CASCADES IN THE AFTERNOONS AND EVENINGS. THE FIRST FALL LIKE COLD
FRONT WILL MOVE ONSHORE SATURDAY NIGHT AND SUNDAY MORNING...FOLLOWED
BY COOL SHOWERS INTO MONDAY. ANOTHER FRONT IS POSSIBLE TUESDAY BEFORE
DRYING LATER NEXT WEEK.

.DISCUSSION...
.SHORT TERM...SATELLITE IMAGERY SHOWS THE UPPER LEVEL SHORT WAVE THAT
MOVED THROUGH LAST NIGHT WILL CONTINUE MOVING OFF TO THE EAST
TODAY...TAKING THE DEEPER MOISTURE WITH IT. MODELS STILL SHOW WEAK
VORTICITY MOVING THROUGH THAT MAY PROVIDE A WEAK TRIGGER BUT WATER
VAPOR IMAGERY SHOW MUCH LESS MOISTURE IN MID AND UPPER LEVELS AS ALSO
SEEN IN THE OAK RAOB. WITH MORE SOUTHWEST FLOW WILL ADJUST CURRENT
FORECAST COVERAGE TO JUST THE OREGON CASCADES INTO THE SOUTHERN COAST
RANGE BUT DROP THE VALLEYS. MODELS SHOW THUNDERSTORM THREAT LESS
FRIDAY AND WILL ONLY HAVE A SLIGHT CHANCE SOUTHERN CASCADE CREST
AREA.

A LITTLE MORE MARINE CLOUDS THIS MORNING...AND NEW MESO IS PICKING
UP ON THIS. MARINE LAYER BUILDS TONIGHT AND FRIDAY...THEN SHOOTS INTO
THE GAPS BY SATURDAY MORNING. MAIN PUSH WAITS FOR THE COLD FRONT
SATURDAY NIGHT. TEMPS INLAND WILL ONLY COOL SLIGHTLY.

NO MARINE ADVISORIES.

.LONG TERM...NO CHANGES. PREVIOUS DISCUSSION FOLLOWS...
EXTENDED MODELS IN GENERAL AGREEMENT.  SAT NIGHT AND SUN DEEP
PROGRESSIVE TROUGH TO PUSH A COLD FRONT THROUGH. AS MODELS HAVE BEEN
CONSISTENT WITH THIS IDEA FOR SEVERAL DAYS...WILL UP POPS TO LIKELY
FOR SUN. COOL ONSHORE FLOW BEHIND FRONT TO BRING A CHANCE FOR SHOWERS
FOR THE NEXT FEW DAYS...BUT BY MIDWEEK UPPER RIDGE STRENGTHENS. WARM
FRONT LIFTS N OF AREA BY WED...SO WILL DROP ALL MENTION OF POPS WED.
TOLLESON

AST 11001 PDX 01111 SLE 11111 EUG 11111

.PQR...NONE.
$$