Special Weather Statement, NWS San Francisco Bay Area, CA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
158 PM PDT WED OCT 10 2012

.DISCUSSION...AS OF 2:00 PM PDT WEDNESDAY...BAY AREA RADARS HAVE
PICKED UP SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THROUGH THE
DAY TODAY AS A STORM SYSTEM CONTINUES TO ROTATE OFF OF THE
CALIFORNIA COAST. RAINFALL AMOUNTS HAVEN'T BEEN IMPRESSIVE BUT IT
IS INTERESTING TO NOTE THAT MOST OF THE RAIN FELL IN THE MIDDLE
THIRD OF THE CWA -- INSTEAD OF THE NORTHERN OR SOUTHERN PORTIONS
WHICH TENDS TO BE MORE COMMON. WE DID GET ONE REPORT FROM FAR
SOUTHWESTERN MONTEREY COUNTY OF AROUND A THIRD OF AN INCH FROM A
STRONG CELL THAT WENT OVER EARLIER. AT THIS TIME THAT IS THE
HIGHEST AMOUNT DETECTED.

EXPECT A CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE SOUTHERN
HALF OF THE CWA THROUGH TONIGHT AS THE LOW SLOWLY PROGRESSES TO
THE SOUTHEAST WHILE THE ATMOSPHERE REMAINS MODERATELY UNSTABLE. AS
THE NIGHT PROGRESSES LIFTED VALUES WILL FLIP BACK TO POSITIVE
NUMBERS HELPING TO GREATLY REDUCE THE RISK OF CONVECTION. ANY
ADDITIONAL RAINFALL SHOULD BE ON THE LIGHT SIDE WITH THE EXCEPTION
OF A BRIEF LOCAL DOWNPOUR DUE TO A STRONGER CELL. IN GENERAL LESS
THAN A TENTH OF AN INCH IS ANTICIPATED.

THE LOW WILL MOVE ONSHORE OVER SOUTHERN CALIFORNIA ON THURSDAY AND
PROGRESS TO NEAR THE FOUR CORNERS ON FRIDAY. BEHIND IT TEMPERATES
WILL START TO WARM AS 500 MB HEIGHTS BUILD BACK TO AROUND 580 DM
ON FRIDAY COMPARED TO 562 TODAY AND THEN UP TO 586 DM OVER THE WEEKEND.
THIS COMBINED WITH INCREASING AMOUNTS OF SUNSHINE WILL HELP TO
BOOST HIGHS BACK INTO THE 70S FOR MANY INTERIOR SPOTS OVER THE
WEEKEND WITH MID 60S TO LOWER 70S AT THE COAST. SOME 80S ARE
DEFINITELY POSSIBLE ON SUNDAY.

LONGER RANGE MODELS BRING A REX BLOCK BACK TO NEAR OUR CWA FOR
NEXT WEEK WITH THE STORM TRACK WELL TO OUR NORTH. HIGHS SHOULD
BE ABOVE NORMAL NEXT WEEK AND COULD APPROACH WELL ABOVE NORMAL
VALUES BY WEDNESDAY. IN FACT...IF THE ECMWFBC VERIFIES WE COULD
SEE 90S BACK IN THE NORTH BAY. DIDN'T FEEL CONFIDENT ENOUGH TO GO
THAT HIGH THAT FAR OUT...BUT IT IS WORTH MENTIONING
&&

.AVIATION...AS OF 10:45 AM WEDNESDAY...MAIN BANDS OF SHOWERS AND
CLOUDS FROM THE UPPER LOW THIS MORNING HAVE MOVED SOUTH AT THIS
HOUR. LOW CLOUDS IN SF BAY ARE RAPIDLY CLEARING AND ALL TERMINALS
SHOULD RETURN TO VFR BY NOON. LIGHT WINDS TODAY. AN ISOLATED
SHOWER OR TWO IS STILL POSSIBLE THIS AFTERNOON. STRATUS POSSIBLE
TONIGHT...LOW CONFIDENCE.

.VICINITY OF KSFO...LOW CIGS TO SCATTER WITHIN THE NEXT HOUR. WEST
WINDS MOSTLY LESS THAN 10 KT. LOW CIGS POSSIBLE AGAIN TONIGHT.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR. LIGHT WINDS.

&&

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

PUBLIC FORECAST: BELL
AVIATION/MARINE: AC

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SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN FRANCISCO CA
341 PM PDT WED OCT 10 2012

CAZ511>513-528-529-102315-
EAST BAY HILLS AND THE DIABLO RANGE CA-NORTHERN MONTEREY BAY
CA-NORTHERN SALINAS VALLEY/HOLLISTER VALLEY AND CARMEL VALLEY
CA-SANTA CLARA VALLEY INCLUDING SAN JOSE CA-SANTA CRUZ MOUNTAINS CA-
341 PM PDT WED OCT 10 2012

...SIGNIFICANT WEATHER ADVISORY FOR SANTA CLARA...SAN BENITO AND
SANTA CRUZ COUNTIES UNTIL 415 PM PDT...

AT 339 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM NEAR GILROY...MOVING WEST NORTHWEST AT 20 MPH.

HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM.

AREAS AFFECTED BY THIS STORM INCLUDE...GILROY...MORGAN HILL...AND
SAN MARTIN.  THIS STORM WILL BE CROSSING US 101 AND CONTINUE WEST
ALONG HIGHWAY 152.

LAT...LON 3692 12179 3718 12171 3706 12145 3690 12150
TIME...MOT...LOC 2239Z 112DEG 17KT 3700 12156

RILEY