Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA

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000
FXUS66 KMTR 072227
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
227 PM PST SUN FEB 7 2016

.SYNOPSIS...STRONG RIDGE OF HIGH PRESSURE WILL AGAIN CREATE
POTENTIAL RECORD WARMTH ACROSS THE BAY AREA AND CENTRAL COAST
TOMORROW. THE RIDGE WILL WEAKEN BY MIDWEEK ALLOWING FOR SOME
COOLING. OUTSIDE OF A SLIGHT CHANCE FOR RAIN OVER THE NORTH BAY
FRIDAY AND FRIDAY NIGHT, DRY WEATHER IS FORECAST.

&&

.DISCUSSION...AS OF 2:30 PM PST SUNDAY...MUCH ABOVE NORMAL
TEMPERATURES ACROSS OUR ENTIRE REGION TODAY WITH MOST LOCATIONS IN
THE MID 60S TO MID 70S. TWO RECORDS HAVE ALREADY BEEN BROKEN
(OAKLAND AIRPORT AND MUSEUM) WITH SEVERAL OTHERS CLOSE TO FALLING
AT THIS HOUR. THE NICE WARM CONDITIONS ARE DUE TO A COMBINATION OF
OFFSHORE FLOW AT THE SURFACE, RIDGE ALOFT, AND VERY WARM
TEMPERATURES ABOVE THE SURFACE (KOAK SOUNDING INDICATED 14C AT 850
MB ON THE 12Z SOUNDING). QUIET WEATHER WILL CONTINUE THROUGH
TONIGHT WITH MOST LOWS IN THE UPPER 40S TO MID 50S. TOMORROW WILL
LIKELY BE A DEGREE OR TWO WARMER WITH 500 MB HEIGHTS FORECAST TO
RISE AN ADDITIONAL DM. WOULD EXPECT A FEW RECORDS TO BE TIED OR
SET ON MONDAY.

THE RIDGE OF HIGH PRESSURE WILL START TO SHIFT TO THE EAST WITH
THE AXIS FORECAST TO BE OVER THE ROCKIES ON TUESDAY. THE AXIS WILL
CONTINUE ITS SLOW PROGRESSION TO THE EAST THROUGH THE REST OF THE
WEEK AS A LONGWAVE TROF NEARS THE WEST COAST. THIS WILL ALLOW
HIGHS TO GRADUALLY LOWER BACK CLOSER TO NORMAL VALUES. VARIOUS
OPERATIONAL MODELS PLUS THE ENSEMBLE MEAN DO INDICATE AN OUTSIDE
SHOT OF LIGHT RAIN OVER THE NORTH BAY FRIDAY AND FRIDAY NIGHT
ASSOCIATED WITH THE TROF. ADDED A SLIGHT CHANCE OF RAIN TO THE
GRIDS FOR MOST OF THE NORTH BAY.

THE TROF QUICKLY MOVES THROUGH WITH A DRY WNW FLOW FORECAST TO
SETUP BEHIND IT. RIGHT NOW RAIN IS FORECAST TO REMAIN WELL NORTH
OF OUR CWA ALTHOUGH WITH A ZONAL FLOW WILL NEED TO SEE IF ANY
DISTURBANCES CAN MAKE IT INTO OUR CWA FROM THE WEST. OFFICIAL 6 TO
10 AND 8 TO 14 DAY FORECASTS FAVOR DRIER THAN NORMAL WEATHER OUT
TO FEBRUARY 21ST.
&&

.AVIATION...AS OF 10:00 AM PST SUNDAY...VFR CONDITIONS PREVAIL WITH
CLEAR SKIES ALTHOUGH A CONTINUED STAGNANT AIRMASS BELOW AN INVERSION
COULD BRING HAZY CONDITIONS TODAY...ESP SJC WHERE PARTICULATE
MATTER IS HIGHEST AND MAY RESULT IN MVFR VSBYS.

LLJ IS NOW AT ITS PEAK ACROSS THE CENTRAL BAY AREA WITH MODERATE
LLWS...NORTHEAST WINDS AT 25 TO 35 KT IN THE 1500-2000 FOOT LEVEL
MSL THIS MORNING INTO THE EARLY AFTERNOON. LLWS WILL DIMINISH IN
THE AFTERNOON WITH LOW LEVEL WINDS ALOFT VEERING TO SOUTHERLY AS
STRONGER WINDS ALOFT SHIFT NORTHWARD...ALTHOUGH MAY CONTINUE AT
STS THROUGH THE AFTERNOON HOURS. CONCERN THAT SOME MIXING COULD
ALLOW A FEW NORTHEAST GUSTS TO AROUND 15 KT AT OAK AND SFO IN THE
AFTERNOON.

FOR MONDAY...OFFSHORE FLOW IS EXPECTED TO CONTINUE BUT MODELS SHOW
EASTERLIES BLO 10 KTS. GENERALLY CLEAR SKIES EXPECTED TO
CONTINUE.

VICINITY OF KSFO...VFR WILL PREVAIL. LIGHT NE FLOW AT THE SFC
WITH MODERATE LLWS EXPECTED INTO THE AFTERNOON. COULD SEE A FEW
GUSTS TO AROUND 15 KT DURING THE AFTERNOON BUT CONFIDENCE IS LOW
WHETHER WINDS WILL MIX DOWN.

SFO BRIDGE APPROACH...SIMILAR TO KSFO.

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

&&

.BEACHES...AS OF 10:45 PM PST FRIDAY...SWELLS OFF THE COAST HAVE
DECREASED TO 7 TO 8 FEET TONIGHT BUT THE SWELL PERIODS CONTINUE AT
14 TO 15 SECONDS. ALTHOUGH THE WAVES ARE LOWER THE LONGER PERIODS
MAKE THE WAVES CAPABLE OF GENERATING STRONG RIP CURRENTS AND LARGE
SHORE BREAK. ADDITIONALLY...WATER TEMPERATURE IS ONLY EXPECTED TO
BE IN THE MID 50S...SO THOSE VENTURING INTO THE WATER WILL ALSO BE
SUBJECT TO A HEIGHTENED RISK OF HYPOTHERMIA.

&&

RECORD HIGHS FOR SUNDAY AND MONDAY AS OF SUNDAY MORNING...

CITY NAME       FEB 7TH HIGH AND YEAR      FEB 8TH HIGH AND YEAR
-------------------------------------------------------------------
KENTFIELD        71 IN 2006                 71 IN 2006
SAN RAFAEL       73 IN 2011                 72 IN 1980
NAPA             79 IN 2011                 73 IN 1987
SAN FRANCISCO    73 IN 2006                 74 IN 2006
SFO AIRPORT      73 IN 1987                 73 IN 2006
OAKLAND MUSEUM   72 IN 1987*                77 IN 2006
OAKLAND AIRPORT  69 IN 1963*                70 IN 2006
RICHMOND         74 IN 2015                 78 IN 2011
LIVERMORE        78 IN 1917                 78 IN 1917
SAN JOSE         76 IN 1963                 75 IN 1987
GILROY           76 IN 2011                 78 IN 1963

MONTEREY         85 IN 1954                 81 IN 1954
SANTA CRUZ       85 IN 1954                 78 IN 1954
SALINAS          82 IN 1987                 83 IN 2006
SALINAS AIRPORT  84 IN 1954                 83 IN 1954
KING CITY        85 IN 1954                 84 IN 2006

* -- INDICATES THAT THE RECORD WAS BROKEN TODAY

&&

.MARINE...AS OF 02:30 PM PST SUNDAY...A LARGE RIDGE OF HIGH
PRESSURE BUILDING OVER THE WESTERN UNITED STATES WILL MAKE FOR
LIGHT TO MODERATE WINDS ACROSS THE COASTAL WATERS TODAY. OFFSHORE
WINDS ARE FORECAST TO DEVELOP MONDAY AND TUESDAY AS THE SURFACE
THERMAL TROUGH DRIFTS OFF THE COAST. SWELL WILL CONTINUE TO SLOWLY
DECAY TODAY BUT BE REPLACED BY ANOTHER BUILDING SWELL TRAIN ON
MONDAY. THE NORTH PACIFIC WILL REMAIN ACTIVE THROUGH THE NEXT WEEK
GENERATING SWELL FOR LATE IN THE WEEK.

&&

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

&&

$$

PUBLIC FORECAST: BELL/R_WALBRUN
AVIATION: WEYGAND
MARINE: SIMS
CLIMATE: R_WALBRUN


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