FXUS66 KMTR 221153
AFDMTR

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

.DISCUSSION...AS OF 3:45 AM PST TUESDAY...MAIN FORECAST CONCERNS
CENTER AROUND WIND FOR TODAY AND TONIGHT ALONG WITH POTENTIAL FOR
FROST AND FREEZING TEMPERATURES TONIGHT AND WEDNESDAY NIGHT.

VERY BREEZY CONDITIONS THIS MORNING ACROSS THE ENTIRE MTR CWA WITH
MOST OF THE STRONG WIND CENTERED AROUND SPOTS NEAR AND OVER THE
WATER. POINT REYES LIGHTHOUSE HAS RECORDED THE HIGHEST SPEEDS WITH
SOME GUSTS TO OVER 50 MPH THROUGH THE OVERNIGHT HOURS. EVEN SOME
URBAN LOCATIONS ARE PICKING UP BREEZY CONDITIONS. AT THIS HOUR SFO...
MRY...AND SJC ARE ALL GUSTING NEAR OR A BIT ABOVE 30 MPH. THE CAUSE
FOR THE WIND IS FRONT THAT WENT THROUGH OUR AREA WITH PLENTY OF CAA
BEHIND IT -- IN FACT TEMPERATURES ARE RUNNING 5 TO 15 DEGREES
COOLER THAN THEY WERE 24 HOURS AGO. RADARS EVEN INDICATED A FEW ECHOS
EARLY THIS MORNING AND A WEATHER OBSERVER AT THE LICK OBSERVATORY
CALLED TO REPORT LIGHT SNOW AT THAT SPOT. FOR TODAY...BREEZY
CONDITIONS ARE EXPECTED TO CONTINUE THROUGH THE DAY TODAY AS THE SFO-
LAS GRADIENT RAMPS UP TO ALMOST 15 MB AND THE CAA CONTINUES.
STRONGEST WINDS SHOULD BE RIGHT AT THE COAST ALONG WITH HIGHER
ELEVATION LOCATIONS. EVEN MUCH OF THE SF BAY SHORELINE THROUGH THE
SANTA CLARA VALLEY CAN EXPECT LOCAL GUSTS OVER 30 MPH FOR TODAY AND
THIS EVENING. HIGHS TODAY WILL STRUGGLE TO GET MUCH ABOVE 50. LOWS
WILL DROP MOSTLY INTO THE 30S TONIGHT. WITH THE WIND CONTINUING
THROUGH THE OVERNIGHT HOURS...ANY FOG DEVELOPMENT SHOULD BE VERY
LIMITED.

MUCH CALMER CONDITIONS ARE FORECAST ON WEDNESDAY AS ALL OF THE
GRADIENTS DROP BY LARGE PERCENTAGES. ALTHOUGH TEMPERATURES WILL ONLY
BE IN THE 50S...PLENTY OF SUNSHINE CAN BE EXPECTED. BY WEDNESDAY
EVENING...THE CLEAR SKIES WILL ALLOW TEMPERATURES TO
QUICKLY DROP. FOG IS EXPECTED TO FORM TO OUR EAST AND WITH A WEAK
OFFSHORE GRADIENT FORECAST BY THE NAM...SOME FOG WILL LIKELY ADVECT
INTO THE EAST BAY. FROST AND FREEZING FOG IS A DEFINITE POSSIBILITY
IN THE COOLEST SHELTERED AREAS OF THE NORTH AND EAST BAY. LOWS WILL
RANGE FROM THE UPPER 20S TO THE UPPER 30S. LITTLE CHANGE IS FORECAST
FOR THURSDAY AND FRIDAY AS A 500 MB RIDGE STAYS IN PLACE ALTHOUGH
TEMPERATURES WILL WARM BACK TO NORMAL VALUES.

NEXT CHANCE FOR PRECIPITATION WILL BE LATE ON SATURDAY AS THE
THE RIDGE MOVES OFF TO THE EAST AND A PACIFIC STORM SYSTEM MOVES INTO
THE WEST COAST. AT THIS TIME...SIGNIFICANT RAINFALL IS NOT EXPECTED
FROM THIS STORM.

FINAL NOTE...SINCE THIS WEEK HAS MANY PEOPLE TRAVELING...
CONDITIONS AROUND SF AND MONTEREY BAY SHOULD BE VERY GOOD WITH THE
ONLY PROBLEM EXPECTED TO BE PATCHY OVERNIGHT FOG ALONG WITH THE
POTENTIAL FOR FROST AND FREEZING FOG IN THE COOLEST SPOTS. FOG
IS ALSO EXPECTED ACROSS THE CENTRAL VALLEY WHICH COULD IMPACT
THOSE DRIVING TO THE LAKE TAHOE AREA. PERSONS TRAVELING TO THE
MIDWEST SHOULD PAY PARTICULAR ATTENTION TO THE FORECASTS AS A LARGE
STORM IS EXPECTED TO IMPACT THAT AREA. MORE INFORMATION CAN BE FOUND
AT WWW.WEATHER.GOV.

&&

.AVIATION...AS OF 3:52 AM TUESDAY...DRY NORTHWEST FLOW HAS DEVELOPED
ACROSS THE REGION.  SKIES HAVE CLEARED AND VFR CONDITIONS ARE
EXPECTED.  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 GUSTS TO 30 KT WILL BE POSS AT KMRY.

&&

.MARINE...AS OF 3:52 AM TUESDAY...STRONG AND GUSTY NORTHWEST FLOW
WILL PREVAIL ACROSS MUCH OF THE COASTAL WATERS TODAY IN THE WAKE OF A
DEPARTING COLD FRONT. LATEST BUOY OBSERVATIONS AND FORECAST MODEL
GUIDANCE INDICATE GALE FORCE CONDITIONS FROM BUOY 12/PIGEON POINT
VICINITY SOUTHWARD. THAT IS NOT TO SAY AN OCCASIONAL GUST TO 35K WILL
NOT BE POSSIBLE NORTHWARD.  IN FACT...A FEW READINGS NEAR PT REYES
HAVE INDICATED GUSTS IN EXCESS 45 KTS. GRANT IT...THAT READING IS
MORE OF AN ISOLATED READING. THEREFORE...WILL CARRY A GALE WARNING
SOUTH OF PIGEON POINT THROUGH THIS EVENING.  MESOSCALE MODELS KEEP
STRONG WINDS THROUGH 03-06Z THIS EVENING BEFORE DIMINISHING. IT
SHOULD ALSO BE NOTED THAT THE GALE WARNING WILL LIKELY VERIFY MORE ON
THE FREQUENT GUSTS (GREATER THAN 34 KTS) THAT THE SUSTAINED WINDS.
ELSEWHERE...SMALL CRAFT CONDITIONS WILL PREVAIL WITH THE EXCEPTION OF
SF BAY. ANYWAY YOU SLICE IT...MARINERS VERNTURING ON THE WATERS TODAY
SHOULD CHECK THE LATEST CONDITIONS BEFORE DEPARTING.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
   .TDY...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: BELL
AVIATION/MARINE: MEHLE

NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO