AREA FORECAST DISCUSSION
NWS SEATTLE WA
AFDSEW 835 AM PST FRI MAR 09 2001
OLD UPR LOW IS OVR CNTRL OREGON THIS MORNING AND CONTINUING TO DIG
S...AS AN UPR RDG MOVES INTO B.C. ACARS REPORTS SHOW N WNDS ALF THRU
PGTSND THOUGH MOST CENTRAL PGTSND METARS ARE STILL LIGHT...EXCEPT FOR
MARINE OBSERVATIONS. LOTS OF LOW LEVEL MSTR WHIDBEY ISL SWD...THOUGH
NW INTR HAS CLEARED OUT ALREADY. NEW MESOETA FCST SOUNDING FOR
SEATTLE SHOWS A FAIRLY UNSTABLE AMS BELOW 5000 FEET THROUGH THE
AFTERNOON...SO EXPECT SCT CLDS AND LOCALLY BKN LAYERS THROUGH THE
AFTERNOON. OTHERWISE INCREASING SUNSHINE IN THE FCST LOOKS GOOD.
SHARP UPR TROF JUST COMING UP ON 140W THIS MORNING IS THE NEXT SYSTEM
DUE TO CROSS W WA. THERE IS A GOOD DEAL OF MID/HIGH LVL MSTR OUT
AHEAD OF THIS TROF...BUT WILL DIMINISH AS THE TROF MOVES ACRS W WA
LATE TONIGHT. NEW 12Z MDLS SMLR TO OLD 00Z RUNS...FCSTG UPR TROF
PASSAGE TO BE DRY. MDLS ALSO SHOW THAT THE UPR TROF WILL BE SHEARING
AWAY FROM THE SURFACE CDFNT...WHICH DISSIPATE BEFORE REACHING THE
COAST ON SATURDAY. GOOD NW LOW LVL FLOW SAT AS SFC HI BUILDS OFFSHORE
SHOULD KEEP CST MOSTLY CLDY BUT INTERIOR SUNNY.
BEHIND THE SATURDAY TROF...THROUGH EARLY NEXT WEEK ZONAL FLOW ALF
CONTINUES ACRS NE PAC/GLFAK AND INTO B.C. WITH THE TILTED UPR RDG
CONTG ACRS WA. THE RIDGE IS STRONG ENOUGH TO BLUNT ANY SIGNIFICANT
PCPN...OTHER THAN DRIBBLES OVER THE N INTR...BUT NOT STRONG ENOUGH TO
KEEP OUT PERIODS OF SIGNIFICANT CLOUD COVER. KAM
UIL 111 SEA 000 OLM 000
.SEW...SMALL CRAFT ADVISORY COAST FOR HEAVY SWELL.
.KATX...VCP21/CSR21...OPERATIONAL.