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Forecast Discussion:Central California
830 PM PDT WED MAR 17 2010
DISCUSSION
AS OF 8:30 PM PDT WEDNESDAY...IN QUIET WEATHER REGIMES LIKE WE HAVE ONGOING IT CAN BE DIFFICULT TO FIND ITEMS TO DISCUSS AT LEAST INITIALLY. TO SUM UP TODAY`S WEATHER FROM A SUBJECTIVE VIEWPOINT IT WAS A BEAUTIFUL DAY. A FEW HIGH TEMPERATURES EVEN BROKE ABOVE THE 80 DEGREE POINT SUCH AS KING CITY...GREENFIELD AND PINNACLES NATIONAL MONUMENT. LARGE OCEAN SWELL PERSISTED ON THE WATERS BUT ARE EXPECTED TO GRADUALLY DECLINE TONIGHT AND THURSDAY. ALL IN ALL MOSTLY CLEAR SKIES SHOULD PREVAIL TONIGHT BUT A FEW PATCHES OF FOG ARE POSSIBLE AROUND DAYBREAK THURSDAY. THURSDAY`S WEATHER LOOKS SIMILAR TO TODAY`S BUT ADDED IN WILL BE A TWIST OF OFFSHORE WIND FLOW. SUBSIDING AIR OFF THE LOCAL MOUNTAINS AND HILLS HAVE A WARMING AND DRYING EFFECT ON THE AIRMASS. OFFSHORE PRESSURE GRADIENTS WILL INCREASE THURSDAY INTO FRIDAY MORNING PER THE LATEST GFS AND WRF MODEL RUNS. THE MODELS AGREE THERE WILL BE A 12 MB OFFSHORE GRADIENT FROM WMC TO SFO BY EARLY FRIDAY MORNING. FORECAST MODELS SHOW A DRY SHORTWAVE TROUGH SLIDING SOUTH ALONG THE CA/NV BORDER DURING THIS TIME. IF THE TROUGH WAS A BIT FARTHER TO THE WEST THIS WOULD NORMALLY ENHANCE THE WINDS OVER THE BAY AREA POSSIBLY TO THE POINT OF NEEDING AN ADVISORY. LOCALLY GUSTY WINDS ARE EXPECTED IN THE EAST BAY HILLS AND NORTH BAY MOUNTAINS THURSDAY AND THURSDAY NIGHT BUT SHOULD REMAIN BELOW ADVISORY LEVELS. FIRE RELATED PRODUCTS ARE NOT SEEN NEEDED AT THIS TIME MAINLY DUE TO HIGHER FUEL MOISTURES. THE STRENGTH OF THE OFFSHORE GRADIENT DIMINISHES FRIDAY. DRY WEATHER IS FORECAST FOR THE REMAINDER OF THE PERIOD. &&
AVIATION
AS OF 4:40 PM PDT WEDNESDAY...HIGH PRESSURE ALOFT WILL MAINTAIN MOSTLY CLEAR SKIES ACROSS THE REGION THROUGH THURSDAY. PATCHY LOW CLOUDS AND FOG MAY DEVELOP NEAR THE OCEAN LATE TONIGHT... BUT ONSHORE FLOW WILL BE TOO WEAK FOR ANY LOW CIGS OR FOG TO DEVELOP AROUND SF BAY. OFFSHORE FLOW WILL BEGIN TO DEVELOP ALOFT LATE TONIGHT AND INCREASE BY LATE THURSDAY. THESE OFFSHORE WINDS MAY RESULT IN LOCAL LLWS LATE THURSDAY INTO THURSDAY NIGHT. VICINITY OF KSFO...VFR CONDITIONS THROUGH THURSDAY. WINDS WILL BE WEST 15G20 KTS THROUGH 04Z...THEN GRADUALLY DIMINISH OVERNIGHT. WINDS WILL TURN LIGHT NORTHEAST ON THURSDAY MORNING...BEFORE TURNING TO THE WEST-NORTHWEST LATE THURSDAY AFTERNOON. WINDS THURSDAY AFTERNOON WILL BE LIGHTER THAN ON WEDNESDAY AFTERNOON. KSFO BRIDGE APPROACH...SAME AS KSFO. MRY BAY AREA TERMINALS...VFR CONDITIONS THROUGH MOST OF THE NIGHT. IFR CIGS MAY DEVELOP NEAR KMRY LATE TONIGHT. IF LOW CIGS DO DEVELOP NEAR MONTEREY BAY...THEY WILL CLEAR BY 16Z THURSDAY. WINDS WILL BE LIGHT. PROPOSED POLICY CHANGE...EFFECTIVE 15Z TUESDAY APRIL 6TH 2010 THE SAN FRANCISCO BAY AREA OFFICE AT MONTEREY WILL BEGIN 3-HOURLY TAF ISSUANCES FOR KSFO. THESE INTERMEDIATE TAFS AT 03Z...09Z...15Z...AND 21Z WILL BE ISSUED AS AMENDMENTS TO THE TAFS ISSUED AT 00Z...06Z... 12Z...AND 18Z. THE INTERMEDIATE TAFS WILL BE ISSUED DURING A 20- MINUTE WINDOW BETWEEN 10 MINUTES BEFORE THE DESIGNATED ISSUANCE HOUR AND 10 MINUTES AFTER THE HOUR. COMMENTS ON THIS PROPOSED RULE-MAKING WILL BE ACCEPTED TO MARCH 19TH. COMMENTS CAN BE ADDRESSED TO THE WEBMASTER AT THE NWS AT MONTEREY AT WWW.WEATHER.GOV/SANFRANCISCO. &&
MTR WATCHES/WARNINGS/ADVISORIES
TNGT...SCA...ALL COASTAL WATERS. SCA...ROUGH BAR SAN FRANCISCO BAR. &&
CLIMATE
HIGH TEMPERATURE RECORDS FOR SELECTED LOCATIONS FOR MARCH 17. SAN FRANCISCO BAY AREA
CITY
...........TEMPERATURE.....YEAR KENTFIELD.........87..............1914 MOFFETT FIELD.....84..............2004 NAPA..............92..............1914 OAKLAND...........85..............2004 KOAK AIRPORT......81..............2004 RICHMOND..........83..............2004 KSFO AIRPORT......82..............2004 SAN FRANCISCO.....85..............1914 SAN JOSE..........88..............1914 SAN RAFAEL........84..............1972 SANTA ROSA........87..............1978 MONTEREY BAY AREA
CITY
...........TEMPERATURE.....YEAR GILROY............89..............1972 KING CITY.........91..............2004 MONTEREY..........84..............2004 SALINAS...........88..............2004 SANTA CRUZ........89..............1914 && $$ PUBLIC FORECAST: CANEPA AVIATION/MARINE: LARRY/DYKEMA CLIMATE: SEA NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO