Freeze Warning 3, NWS San Francisco Bay Area, CA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
844 AM PST MON DEC 18 2006

.DISCUSSION...WHAT A FROSTY START TO THE DAY. MOST LOCATIONS ACROSS
THE BAY AREA THIS MORNING WERE COLD AND IN THE UPPER 20S TO LOWERS
30S.  IN FACT...A FEW LOCATIONS IN THE SHELTERED VALLEYS OF THE
NORTHBAY ACTUALLY TUMBLED INTO THE UPPER TEENS AND LOWER 20S.
BESIDES THE COLD MORNING LOWS...WIDESPREAD FROST WAS ALSO OBSERVED
ACROSS MUCH OF THE DISTRICT. THIS MORNING HAS BEEN THE
COLDEST SO FAR THIS SEASON AND IS SURPRISINGLY COLDER THAN MUCH OF
NEW ENGLAND. THE COLD TEMPERATURES ARE RIGHT ON CUE WITH THE START OF
THE WINTER SOLSTICE ONLY A FEW DAYS AWAY. THE OAKLAND MUSEUM WAS THE
ONLY LOCATION TO OFFICIALLY BREAK ANY RECORDS FOR LOW TEMPERATURES
(SEE SFORERMTR).

THIS COLD SNAP IN THANKS TO A RELATIVELY COLD AIRMASS AND STRONG
HIGH PRESSURE COVERING MUCH OF THE PAC NW AND THE EPAC. THIS LARGE
AREA OF HIGH PRESSURE HELPED TO CREATE LIGHT WINDS AND DRY
CONDITIONS...WHICH IS IDEAL FOR RADIATIONAL COOLING. SOME
RECOVERY IS EXPECTED TODAY WITH WINDS BECOMING NE OR
SLIGHTLY OFFSHORE. HOWEVER...HIGH TEMPERATURES SHOULD BE CLOSE TO
NORMAL OR JUST BELOW CLIMO.

AS FOR TONIGHT...LOW TEMPERATURES WILL ONCE AGAIN MAKE A RUN AT THE
RECORD BOOKS.  TONIGHT WILL BE SIMILAR TO LAST NIGHT WITH
RADIATIONAL COOLING...BUT WOULD NOT BE SURPRISED IF MOST LOCATIONS
CAME IN A FEW DEGREES COLDER TOMORROW MORNING. THE CURRENT FORECAST
HAS A FREEZE WATCH FOR TONIGHT(SFONPWMTR)...BUT THIS WILL LIKELY BE
UPGRADED TO A FREEZING WARNING. AS POINTED OUT BY THE NIGHT
SHIFT...THE SFO BAY ZONE MAY NEED A FROST ADVY.

TOMORROW AND TOMORROW TONIGHT WILL BE SIMILAR TO TODAY WITH NEAR
NORMAL HIGHS  AND COLD OVERNIGHT LOWS. THERE AFTER...THE WEATHER
WILL REMAIN QUIET UNTIL THURSDAY WHEN A COLD FRONT IS FORECAST TO
APPROACH FROM THE WEST.

&&

.AVIATION...PREVIOUS...DRY OFFSHORE FLOW BRINGING CLEAR SKIES THROUGH
TUESDAY. WINDS WILL BE LIGHT OFFSHORE OVER THE SFO BAY AREA BUT
WINDS IN THE EAST BAY HILLS WILL BE LOCALLY 15-20 MPH. OFFSHORE FLOW
NOT EXPECTED TO BE STRONG IN THE AFTERNOON AND A WINDS WILL
BECOME LIGHT ONSHORE.

&&

.MTR...WATCHES/WARNINGS/ADVISORIES...
             .TNGT/EARLY TUESDAY...FREEZE WATCH FOR MOST
              INLAND AREAS OF THE SAN FRANCISCO AND MONTEREY
              BAY AREAS.

PUBLIC FORECAST: MEHLE
AVIATION/MARINE: W PI/C WALBRUN

NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
430 AM PST MON DEC 18 2006

CAZ506-507-510-513-514-516-190000-
SOUTHERN SALINAS VALLEY/ARROYO SECO AND LAKE SAN ANTONIO-
NORTH BAY INTERIOR VALLEYS-NORTH BAY MOUNTAINS-
EAST BAY INTERIOR VALLEYS-SANTA CLARA VALLEY INCLUDING SAN
JOSE-MONTEREY BAY/NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL
VALLEY-
430 AM PST MON DEC 18 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE INLAND AREAS OF THE
SAN FRANCISCO AND MONTEREY BAY AREAS.

.DAY ONE...TODAY AND TONIGHT

COLD TEMPERATURES ARE EXPECTED EARLY THIS WEEK. A FREEZE WATCH HAS
BEEN ISSUED FOR LATE MONDAY NIGHT AND TUESDAY MORNING. COLDEST
TEMPERATURES ARE EXPECTED IN THE INLAND VALLEYS WHERE OVERNIGHT LOWS
ARE EXPECTED TO DROP INTO THE MID TO UPPER 20S.

* FREEZE WATCH...SEE SFONPWMTR - WWUS76 KMTR FOR DETAILS *

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

COLD OVERNIGHT LOWS ARE EXPECTED ONCE AGAIN TUESDAY NIGHT AND EARLY
WEDNESDAY. OTHERWISE NO HAZARDOUS WEATHER IS EXPECTED.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

BRENCHLEY