FXUS66 KMTR 030646
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
820 PM PST WED DEC 2 2009

...MAJOR PATTERN CHANGE EXPECTED NEXT WEEK...

.DISCUSSION...AS OF 8:20 PM PST WEDNESDAY...COOL TEMPERATURES WERE
EXPERIENCE BY ALL TODAY AS THE EXPANDING MARINE LAYER ALLOWED FOR
QUITE AN EXTENSIVE INLAND PUSH OF LOW CLOUDS OVERNIGHT LAST NIGHT.
TEMPERATURES NEVER REACHED THEIR POTENTIAL TODAY AS LOW CLOUDS
SHIELDED MANY AREAS FROM THE LOW ANGLE WINTER RAYS OF THE SUN. MOST
AREAS REPORTED HIGHS IN THE 40S AND 50S WITH A FEW 60S SPRINKLED IN
THERE FOR GOOD MEASURE. THE CLIMATE STATION IN MONTEREY REPORTED A
RECORD MINIMUM HIGH FOR TODAY OF 49 DEGREES. BREAKING ITS PREVIOUS
RECORD OF 55 DEGREES FOR THIS DAY SET BACK IN 1972.

CURRENT OBSERVATIONS AND SATELLITE IMAGERY REVEAL EXTENSIVE STRATUS
ALONG THE COAST AND SOME COASTAL VALLEYS. THE MARINE LAYER IS
CURRENTLY AROUND 1200 FEET PER THE FORT ORD PROFILER WITH CEILINGS
AROUND 600-900 FEET PER METAR OBSERVATIONS. A SIMILAR NIGHT TO LAST
NIGHT IS EXPECTED WITH LATE CLEARING DURING THE MORNING HOURS ON
THURSDAY. THIS PATTERN IS EXPECTED TO REPEAT ITSELF THURSDAY NIGHT
INTO FRIDAY AS WELL.

EXTENDED PERIOD...MODELS REMAIN ON TRACK FOR A MAJOR PATTERN CHANGE
EXPECTED TO BEGIN DURING THE LATER HALF OF THIS COMING WEEKEND.
DETAILS ARE STARTING TO COME INTO FOCUS WITH THE GFS...WHICH HAS
BEEN THE OUTLIER...BEGINNING TO TREND WETTER. (FROM PREVIOUS
DISCUSSION...THE REMNANTS OF EX TYPHOON NIDA SHEARS APART WITH A
PIECE OF IT EJECTING INTO THE WESTERLIES. THIS HELPS ENERGIZE THE
EAST ASIAN JET. AS THE UPPER LOW STALLS OVER THE PACIFIC NW THE RIDGE
ALONG 140 BEGINS TO PINCH OFF. THE STRONG JET THEN UNDERCUTS THE
RIDGE WHICH WILL BE CENTERED OVER SOUTHERN ALASKA. THIS WILL ALLOW
A SERIES OF STORMS TO MOVE TO THE COAST OVER THE NEXT WEEK.)

THIS COMING WEEK HAS THE POTENTIAL TO BRING EXCESSIVE RAIN TO THE
REGION AS WELL AS STRONG WINDS. RAIN IS EXPECTED EVERYDAY NEXT WEEK
WEEK. THEREFORE THIS IS A GOOD TIME TO STOCK UP ON EMERGENCY SUPPLIES
IN THE EVENT OF POWER OUTAGES AND OTHER WEATHER RELATED PROBLEMS.
STAY TUNED TO THE NOAA WEATHER RADIO OR VISIT OUR WEBSITE FOR THE
LATEST WEATHER INFORMATION.

FORECAST REMAINS ON TRACK NO UPDATES NEEDED.

&&

.AVIATION...AS OF 10:30 PM WEDNESDAY...LOW CLOUDS ARE SPREADING
INLAND WITH CEILINGS NEAR OR BELOW 1000 FEET. COULD SEE SOME
VISIBILITIES BELOW 3 MILES AT SJC AND STS. CLEARING WILL BE SLOW TO
TAKE PLACE THURSDAY MORNING DUE TO LIGHT WINDS SO A LATE BURNOFF TIME
OF 19-20Z IS EXPECTED.

VICINITY OF KSFO...CEILINGS AT OR SLIGHTLY BELOW 1000 FEET
WITH OCCASIONAL VISIBILITIES DOWN TO 3-5 MILES. CLEARING WILL BE SLOW
TO TAKE PLACE THURSDAY MORNING DUE TO WEAK PRESSURE GRADIENTS. ALATE
BURNOFF TIME OF 19Z IS EXPECTED.

KSFO BRIDGE APPROACH...CEILINGS AT OR SLIGHTLY BELOW 1000 FEET
WITH OCCASIONAL VISIBILITIES DOWN TO 3-5 MILES. CLEARING WILL BE SLOW
TO TAKE PLACE THURSDAY MORNING DUE TO WEAK PRESSURE GRADIENTS. ALATE
BURNOFF TIME OF 20Z IS EXPECTED.

MRY BAY AREA TERMINALS...CEILINGS AT OR SLIGHTLY BELOW 1000 FEET
WITH OCCASIONAL VISIBILITIES DOWN TO 3-5 MILES. CLEARING WILL BE SLOW
TO TAKE PLACE THURSDAY MORNING DUE TO WEAK PRESSURE GRADIENTS. ALATE
BURNOFF TIME OF 19Z IS EXPECTED.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
    .NONE

$$

PUBLIC FORECAST: CW
AVIATION/MARINE: W PI

NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO