866 
FXUS66 KPQR 011609
AFDPQR

NORTHWEST OREGON AND SOUTHWEST WASHINGTON FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
900 AM PDT SUN JUN 1 2003

.SYNOPSIS...A WEAK FRONT ALONG THE COAST WILL DISSIPATE TODAY AS IT
PUSHES INLAND. ONE LAST WEAK FRONT WILL FALL APART AS IT MOVES ACROSS
THE AREA TONIGHT WITH MINIMAL IMPACT. HIGH PRESSURE WILL STRENGTHEN
IN EARNEST ACROSS THE FORECAST AREA WITH THERMAL LOW PRESSURE
DEVELOPING ALONG THE COASTLINE BY MONDAY MORNING. HIGH PRESSURE WILL
REMAIN IN CONTROL OF OUR WEATHER THROUGH THE WEEK WITH OFFSHORE FLOW
AND WARM SUNNY WEATHER.

.DISCUSSION...
.SHORT TERM...MORNING SATELLITE PICTURES SHOW A BAND OF LOW CLOUDS IN
THE MARGINAL VFR RANGE ALONG THE COAST THAT IS THE REMAINS OF A VERY
WEAK COLD FRONT. THIS WILL BREAK APART MORE IN PLACE TODAY WITH ONLY
SOME FRAGMENTS MAKING IT INLAND. AREAS ALONG THE COAST SHOULD CLEAR
OUT NICELY THIS AFTERNOON WITH JUST RESIDUAL CLOUDS ALONG THE NORTH
COAST MOUNTAINS. A SECOND WEAK FRONT APPROACHING 130 DEGREES W THIS
MORNING WILL PRODUCE INCREASING ONSHORE SURFACE PRES GRADIENTS THIS
EVENING AND A MARINE PUSH TONIGHT. THE GFS SHOWS POSITIVE VORTICITY
ADVECTION OVER THE FORECAST AREA AT 06Z ALONG WITH A WESTERLY JET
SEGMENT INTO CENTRAL OREGON...AND THE 1000 MILLIBAR PROGNOSIS
INDICATES MARINE AIR SURGING INLAND INTO THE WILLAMETTE VALLEY AT
THAT TIME...NOT EXPECTING A DEEP ENOUGH LAYER FOR PRECIP INLAND BUT
WILL PUT SOME DRIZZLE COAST AND WEST SLOPES OF THE COAST RANGE AND
INCREASE CLOUDS INLAND. THE MARINE LAYER WILL BREAK APART WITH
DAYTIME HEATING MONDAY AND THE FLOW BECOMES INCREASINGLY OFFSHORE.
MONDAY NIGHT AS THE SURFACE THERMAL LOW PRESSURE TROUGH DEVELOPS
ALONG THE COAST. A HIGH AMPLITUDE UPPER LEVEL RIDGE WILL THEN BUILD
NORTH ALONG 130 W WITH SUBSIDENCE DRYING AND OFFSHORE FLOW DOMINATING
THE WEATHER REGIME.

.LONG TERM...A HIGH AMPLITUDE UPPER LEVEL RIDGE OFF THE COAST AND DRY
OFFSHORE WILL CONTINUE. THE GFS ATTEMPT TO BREAK THE UPPER RIDGE DOWN
SATURDAY AND NEXT SUNDAY HAS CHANGED APPEARANCE WITH THIS MODEL RUN
AND MAY YET BE PREMATURE SO CURRENT FORECAST OF ONLY SLIGHT CHANGES
THEN SEEMS A GOOD WAY TO GO.  WILLSON

AST 12100  PDX 01100  SLE 00000  EUG 00000

.PQR...SMALL CRAFT ADVISORY FROM CASCADE HEAD TO FLORENCE.

$$