FXUS66 KMTR 281848
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
1045 AM PST SAT NOV 28 2009

UPDATED FOR AVIATION DISCUSSION

.DISCUSSION...AS OF 9:45 AM SATURDAY...SHORT TERM WEATHER ISSUES DEAL
WITH WINDS IN THE HILLS...THEN COOL TEMPS AT NIGHT. OTHERWISE
WEATHER LOOKS MILD AND QUIET FOR MUCH OF THE UPCOMING WEEK.

SHORT TERM...ISSUED A LOCAL STORM REPORT WITH SOME OF THE HIGHER
REPORTED WIND GUSTS THIS MORNING IN THE HILLS. WIND ADVISORY IS UP
FOR THE NORTH AND EAST BAY HILLS ABOVE 1000 FEET AND THIS LOOKS TO
BE VERIFYING AT THIS TIME WITH STRONG WINDS EXPECTED THROUGH THE
DAY. WIND GUSTS FROM 40 TO 66 MPH HAVE BEEN RECORDED SO FAR. WINDS
ARE BEING GENERATED ON THE BACKSIDE OF THE UPPER LOW THAT BROUGHT
OUR INCLEMENT WEATHER YESTERDAY. THE MAIN LOW IS NOW OVER SOUTHERN
CALIFORNIA WITH SOME LIGHTNING STRIKES NOTED DOWN THERE AS WELL AS
SNOW LEVELS DOWN TO AROUND 4500 FEET. OUTSIDE OF THE WINDS EXPECT A
SUNNY AFTERNOON WITH TEMPS IN THE LOWER 60S.

MOS GUIDANCE TONIGHT SHOWS TEMPS COOLING OFF BUT BELIEVE THAT WINDS
JUST ABOVE THE BOUNDARY LAYER WILL PRECLUDE ANY UNUSUALLY COLD
TEMPS. WILL FLIRT WITH 30 DEGREE READINGS IN THE USUAL COLD VALLEYS
OF THE NORTH BAY AND INTERIOR MONTEREY COUNTY BUT NO HEADLINES
EXPECTED. WILL HAVE TO CONSIDER EXTENDING THE WIND ADVISORY WHICH
CURRENTLY EXPIRES AT 5 PM TODAY. AGREE THAT STRONGEST WINDS MAY BE
HAPPENING RIGHT NOW BUT MORE GUSTS IN EXCESS OF 45 MPH APPEAR
POSSIBLE TONIGHT AS WELL.  WILL MONITOR TRENDS AND MAKE THAT CALL
WITH THE AFTERNOON PACKAGE.

FROM SUNDAY THROUGH AT LEAST THE MIDDLE OF NEXT WEEK WOULD EXPECT
QUITE WEATHER WITH MOSTLY CLEAR SKIES AND SEASONABLE TEMPS OR
TRENDING A FEW DEGREES ABOVE NORMAL WITH RIDGING IN PLACE. THE
CURRENT LOW OVER SOCAL WAS NOT MODELED WELL SEVERAL DAYS OUT AND
CURRENT LONG RANGE MODELS ARE REALLY ALL OVER THE BOARD LEADING TO
BELOW NORMAL CONFIDENCE IN THE MEDIUM AND LONG RANGE FORECASTS.
FOR EXAMPLE THE LATEST EURO FROM 00Z LAST NIGHT BRINGS A PIECE OF
ENERGY AND ASSOCIATED RAIN TOWARDS THE BAY AREA AS EARLY AS TUESDAY
NIGHT/WEDS MORNING. AT THIS TIME AM FULLING EXPECTING THE 12Z EURO
TO NOT SHOW ANY HINT OF THIS SOLUTION AS THE GEM/GFS/NAM AND UKMET
MODELS SHOW RIDGING WITH NO RAIN CHANCES AT ALL. SO THE USUALLY
SUPERIOR EURO MODEL IS AN OUTLIER.  MODEL CONSENSUS AND ENSEMBLE
FORECAST WOULD THEN SUGGEST A NICE WEEK OF WEATHER IN STORE FOR
NORTHERN CALIFORNIA AND MUCH OF THE WEST COAST WITH STRONG RIDGING
AND TEMPS AVERAGING ABOVE NORMAL WITH NO PRECIP.

MUCH INTERNAL OFFICE DEBATE ABOUT THE 1-3 WEEK FORECAST TRENDS AS
MJO INDICES AND EL NINO FORECASTS ARE MONITORED. ON TUESDAY THE
CALENDAR WILL TURN TO DECEMBER AND SEVERAL WEEKS AGO THERE WAS
INCREASING CONFIDENCE OF WET WEATHER BY THE FIRST WEEK OF DECEMBER.
DONT SEE THAT HAPPENING NOW. MEANWHILE THE CPC FOLKS CONTINUE TO
MONITOR THE POTENTIAL FOR A WESTERLY BREAK THROUGH AND THUS
INCREASED POTENTIAL FOR STORMINESS ALONG THE WEST COAST. LATEST
WHEELER DIAGRAMS DO SHOW THE MJO SUSTAINING ITSELF IN SPITE OF THE
MODELS SHOWING IT DISSIPATING. IN ADDITION AS WE HEAD TOWARDS THE
MIDDLE OF DECEMBER CLIMATOLOGY IN COMBINATION WITH AT LEAST A
MODERATE EL NINO GIVE SOME HOPE FOR WEST COAST RAIN. HOWEVER THE
GEM AND GFS SHOW A VERY COLD TROUGH OVER THE WEST COAST BY NEXT
WEEK THAT ORIGINATES FROM CANADA SO IT WOULD BE MAINLY DRY. POINT
BEING WE MAY NEED TO FOCUS ON A COOL OUTBREAK BEFORE WE GET TOO
EXCITED ABOUT ANY WET WEATHER POTENTIAL. SHOULD THE LONG-WAVE 500 MB
HEMISPHERIC PATTERN GET OVERLY AMPLIFIED IT WOULD THEN MAKE SENSE FOR
THE PATTERN TO BREAK DOWN WITH A CHANGE TO A WET WX LATER IN THE
MONTH.

&&

.AVIATION...AS OF 10:45 AM PST SATURDAY...CAVU CONDITIONS FOR THE
CENTRAL COAST AND S.F.BAY AREA FOR THE FORECAST PERIOD. THE MAIN
CONCERN WILL BE STRONG WINDS JUST ABOVE THE SURFACE. TURBULENCE AND
LOW LEVEL WIND SHEAR AROUND THE BAY AREA THROUGH 02Z AS SURFACE
WINDS DIFFERENT DIRECTION AND/OR LIGHTER SPEED THAN WINDS AT 30-
40KT WITHIN 2000 FEET OF THE SURFACE INTO THE EARLY EVENING HOURS.

VICINITY OF KSFO...CAVU. LOW LEVEL WIND SHEAR AND TURBULENCE UNTIL
02Z DUE TO N TO NE GUSTY WINDS OF 30-40KT AT 2000 FEET.

KSFO BRIDGE APPROACH...SAME AS KSFO.

MRY BAY AREA TERMINALS...CAVU. GUSTY SURFACE WINDS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
    .TDY...HIGH SURF ADVISORY ON THE COAST TONIGHT THROUGH 4 PM
           TODAY.
        ...GALE WARNING...ALL COASTAL WATERS
        ...SCA FOR ROUGH BAR...SF BAR
        ...WIND ADVISORY FOR THE NORTH AND EAST BAY HILLS TIL 5 PM

$$

PUBLIC FORECAST: RWW
AVIATION/MARINE: GUDGEL

NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO