FXUS66 KMTR 221724
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
924 AM PST TUE DEC 22 2009

.DISCUSSION...AS OF 8:45 AM PST TUESDAY...FORECAST FOCUS ON BREEZY
CONDITIONS TODAY...OVERNIGHT COOL TEMPS AND DRY WEATHER AT LEAST
THROUGH SATURDAY.

IN THE SHORT TERM...SKIES ARE MOSTLY SUNNY THIS MORNING ACROSS
NEARLY THE ENTIRE BAY AREA...SPARE A FEW CLOUDS ALONG THE COAST.
BREEZY CONDITIONS CONTINUE...MAINLY IN THE HILLS OF THE NORTH AND
EAST BAY WITH SUSTAINED WINDS 15-20 MPH WITH GUSTS 30-35 MPH.
OVERNIGHT MT TAM GUSTED TO 61 MPH WITH 49 MPH GUST LAST HOUR. THE
WINDS ARE SUPPORTED BY MODERATE ONSHORE GRADIENTS OF 6 MB DOWN THE
COAST FROM SFO TO SANTA BARBARA AND 16 MB FROM SFO TO LAS VEGAS.
OVERALL TREND SHOULD BE FOR WINDS TO DECREASE THROUGH THE DAY TODAY
THEN PICKUP AGAIN IN THE HILLS...MORE FROM A NORTHEAST DIRECTION AS
HIGH PRESSURE BUILDS INTO THE GREAT BASIN. HOWEVER FOR THE MOST PART
WINDS NOT EXPECTED TO REACH WIND ADVISORY CRITERIA. THE POST-
FRONTAL AIRMASS IS ALSO MUCH DRIER...SO THAT ALONG WITH WINDS ALOFT
SHOULD KEEP THE BOUNDARY LAYER PRETTY DRY TONIGHT LEAVING ONLY SOME
PATCHY VALLEY FOG. WITH EACH PASSING NIGHT VALLEY FOG WILL LIKELY
BECOME MORE WIDESPREAD AS THE PATTERN STAGNATES AND HIGH PRESSURE
ALOFT STRENGTHENS THE LOW-LEVEL INVERSIONS.

SO WEDS THROUGH FRIDAY LOOK SUNNY WITH SEASONABLE AFTERNOON HIGHS
INTO THE UPPER 50S TO NEAR 60 COURTESY OF HIGH PRESSURE BUILDING IN
FROM THE WEST. LOOKS LIKE IDEAL TRAVEL WEATHER UP AND DOWN THE
STATE OF CALIFORNIA LEADING INTO THE XMAS HOLIDAY.

NEXT PRECIP CHANCES LOOK TO BE BY ABOUT SUNDAY...HOWEVER THAT SYSTEM
IS LOOKING WEAK AT THIS TIME. AS THE MODELS HAVE BEEN TRYING TO DO
FOR MUCH OF THE PAST MONTH...TRYING TO BRING A STORM IN UNDER THE
RIDGE. THE JUST RECEIVED 12Z GFS SHOWS THIS AGAIN BUT THE SYSTEM
REALLY SHEARS APART. NONETHELESS THE CURRENT FORECAST HAS A CHANCE
OF RAIN ON SUNDAY AND WILL LIKELY LEAVE AS IS FOR NOW...DEPENDING
ON WHAT THE 12Z EURO SHOWS.

LONGER RANGE MODEL SOLUTIONS HAVE BEEN SUGGESTING A POTENTIALLY
STRONGER STORM BY LATER NEXT TUESDAY OR WEDS. WILL CONTINUE TO
MONITOR.

&&

.AVIATION...AS OF 9:24 AM TUESDAY...DRY NORTHWEST FLOW HAS
DEVELOPED ACROSS THE REGION WITH CLEAR SKIES AND VFR CONDITIONS
EXPECTED THROUGH TONIGHT. THE CONCERN FOR TODAY WILL BE THE GUSTY
WINDS.

VICINITY OF KSFO...VFR CONDITIONS THROUGH TONIGHT. NW WINDS WILL BE
SUSTAINED IN THE TEENS TO 20 KT WITH OCCASIONAL GUSTS TO 30 KT.

KSFO BRIDGE APPROACH...SAME AS KSFO.

MRY BAY AREA TERMINALS...VFR CONDITIONS PREVAIL. NW WINDS OF 10 TO
20 KT WITH HIGHER GUSTS POSSIBLE AT KMRY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
   .TDA...SCA...PT ARENA TO PIGEON PT 0-60 NM AND MRY BAY
       ...SCA...ROUGH BAR
       ...GALE WARNING...PIGEON PT TO PT PIEDRAS BLANCAS 0-60 NM

$$

PUBLIC FORECAST: RWW
AVIATION/MARINE: SSA

NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO