AREA FORECAST DISCUSSION
NWS SEATTLE WA
AFDSEW 230 AM PST SUN FEB 9 2003
.SYNOPSIS...HIGH PRESSURE WILL REMAIN OVER THE REGION FOR THE NEXT
WEEK. THIS WILL RESULT IN VARYING AMOUNTS OF LOW CLOUDS AND FOG EACH
NIGHT. THE FOG AND LOW CLOUDS WILL THEN BURN OFF TO VARYING DEGREES
DURING THE DAYTIME PERIODS.
.DISCUSSION...BIG RIDGE WILL BE THE MAIN PLAYER IN THIS PART OF THE
WORLD. HOWEVER A SHORTWAVE ROUNDING THE TOP OF THE RIDGE WILL DROP
ACROSS THE AREA TONIGHT PROVIDING A BIT OF A FORECAST CHALLENGE.
WEAK SFC TROF WILL MOVE THROUGH THE AREA AS WELL WITH ONSHORE SFC
PRESSURE GRADIENTS DEVELOPING DURING THE DAY AND CONTINUING INTO
TONIGHT. WAVE IS WEAK ENOUGH THAT NO PRECIP WILL BE GENERATED AND
ACTUALLY WILL BARELY HAVE ANY MID OR HIGH CLOUDS. IT WILL AFFECT
THE LOW LEVELS HOWEVER. STATISTICAL GUIDANCE SUGGESTS THAT WILL BE
A MOSTLY SUNNY AFTERNOON. AT THIS POINT JUST DON'T SEE IT. ACARS
DATA AND PROFILER INDICATE INVERSION AROUND 1600 FEET WITH SATURATED
AIR THERE DOWN...SIMILAR TO SAT. AS THE UPPER WAVE APPROACHES
EXPECT THIS LAYER TO DEEPEN...LIFTING THE CLOUD LAYER HOWEVER WITH
CAP REMAINING FEEL THAT THE CLOUD LAYER WILL THIN AND PERHAPS BECOME
BROKEN INLAND BUT NOT MOSTLY SUNNY. THEREFORE...SHADED MORE
PESSIMISTIC WITH THE CLOUD FORECAST AND DROPPED TEMPS BACK A FEW
DEGREES.
TONIGHT...STILL HAVE ONSHORE FLOW...BUT IS WEAKENING LATER PART OF
THE NIGHT. PLENTY OF STRATUS OFFSHORE AND WITH ONSHORE FLOW EXPECT
MOSTLY CLOUDY CONDITIONS ACROSS THE AREA. WOULD NOT BE SURPRISED TO
SEE SOME DRIZZLE ALONG THE COAST AND POSSIBLY OVER THE NORTHERN
SOUND AREA. ALREADY MENTIONED IN THE COASTAL ZONE.
MONDAY...FLOW ACROSS THE AREA BECOMES NORTHERLY AND THIS WILL HELP
TO SLOWLY CLEAR OUT THE CLOUD COVER THROUGH THE DAY. WHOLE SCENARIO
IS VERY SUMMER LIKE. EXPECT MOSTLY CLEAR SKIES WITH A LIGHT
NORTHERLY BREEZE MONDAY EVENING. THIS WILL BE A GOOD SETUP FOR FOG
DEVELOPMENT IN THE AREAS WHERE IT DOESN'T FROST OUT. TONED BACK
MENTION OF CLOUDS AND DROPPED LOWS A BIT.
TUE ONWARD...FLOW BECOMES MORE NORTHEASTERLY THROUGH THIS PERIOD
ALTHOUGH PRESSURE GRADIENT MAY BE OVERFORECAST BY THE MODELS AS HAS
GENERALLY BEEN THE CASE THIS YEAR. LOW COMING ONSHORE WILL BE FAR
ENOUGH SOUTH TO HAVE NO IMPACT ON OUR AREA. THEREFORE WILL CONTINUE
TO HAVE NICE WEATHER WITH AREAS OF NIGHT AND MORNING CLOUDS.
UIL 011 SEA 000 OLM 000
.KSEW...NONE.
.KATX...VCP32/CSR32...OPERATIONAL.
CERNIGLIA