Strong Wind in California, February 8, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
352 AM PST TUE FEB 8 2011

.DISCUSSION...AS OF 3:30 AM PST TUESDAY MORNING...TEMPERATURES
YESTERDAY AFTERNOON CLIMBED WELL ABOVE NORMAL FOR THE BEGINNING OF
FEBRUARY.  DAYTIME HIGH TEMPERATURES ROSE TO THE MID 60S TO MID
70S...WHICH IS BETWEEN 5 AND 15 DEGREES ABOVE NORMAL. CLEAR SKIES
AND A RELATIVELY DRY AIRMASS WOULD NORMALLY ALLOW TEMPERATURES TO
FALL SIGNIFICANTLY OVERNIGHT.  HOWEVER...WINDS FROM THE NORTH HAVE
KEPT MOST TEMPERATURES WARMER COMPARED TO THIS TIME LAST NIGHT.
CURRENTLY TEMPERATURES ARE IN THE MID 40S TO MID 50S...AND ARE
FORECAST TO FALL ANOTHER 5 TO 10 DEGREES.

THE BIG STORY OVERNIGHT HAS BEEN THE GUSTY NORTHERLY WINDS THROUGH
THE REGION. FREQUENT GUSTS BETWEEN 20 AND 30 MPH HAVE BEEN
OBSERVED...WITH OCCASIONAL GUSTS TO 40 OVER THE HIGHER ELEVATIONS.
THE SFO-ACV GRADIENT PEAKED AROUND 04Z TODAY AT -10.3 MB. SINCE THEN
IT HAS BEEN STEADILY DECREASING AND IS FORECAST TO FALL NEAR -8 MB
THIS AFTERNOON.

FORECAST HIGH TEMPERATURES TODAY ARE MUCH COOLER COMPARED TO
YESTERDAY.  BOTH THE WRF AND NAM12 INDICATE 850 MB TEMPERATURES
FALLING AROUND 3 DEGREES C OVER THE NEXT 12 HOURS.  THIS WILL
ALLOW NEAR NORMAL DAYTIME HIGH TEMPERATURES...WITH READINGS IN THE
UPPER 50S TO MID 60S. AFTER TODAY...DAYTIME HIGH TEMPERATURES WILL
STEADILY RISE THROUGH THE REST OF THE WORK WEEK.

THE UPPER LEVEL RIDGE THAT HAS DOMINATED THE AREA OVER THE LAST WEEK
AND A HALF WILL BEGIN TO BREAK DOWN LATER THIS WEEK.  BOTH THE GFS
AND ECMWF PUSH THE RIDGE EAST AND BRING A SLIGHT CHANCE OF
PRECIPITATION TO THE AREA LATER THIS WEEKEND.  THERE IS STILL QUITE A
BIT OF UNCERTAINTY ABOUT THE TIMING AND AMOUNT OF PRECIPITATION WITH
THE RAIN THIS WEEKEND...AS BOTH MODELS HAVE BACKED OFF SIGNIFICANTLY
DURING THE LAST SEVERAL RUNS.  IT NOW APPEARS THE BEST CHANCE
FOR RAIN THIS WEEKEND WILL OCCUR DURING THE DAY SUNDAY OVER THE NORTH
BAY.

THE BETTER SHOT OF RAIN NOW LOOKS TO COME DURING THE MIDDLE OF
NEXT WEEK.  A STRONG UPPER LOW WILL DEEPEN NEAR THE GULF OF ALASKA
AND DROP SOUTH TOWARDS THE CALIFORNIA COAST.  ALTHOUGH IT IS STILL
EARLY...MOST MEDIUM RANGE MODELS ARE INDICATING SIGNIFICANT RAINFALL
OVER THE REGION WITH THIS STORM.

&&

.AVIATION...AS OF 3:40 AM PST TUESDAY...HIGH PRESSURE POSITIONED
OVER THE EASTERN PACIFIC IS INTERACTING WITH LOW PRESSURE OVER THE
INTERMOUNTAIN WEST TO PRODUCE STRONG NORTHERLY WINDS AROUND THE AREA
THIS MORNING. AT THIS POINT WINDS ARE NOT EXPECTED TO REACH AVIATION
WEATHER WARNING LEVELS BUT THERE IS POTENTIAL LATER THIS AFTERNOON
SO WILL CONTINUE TO MONITOR THE SITUATION AND POSSIBLY UPDATE AS THE
DAY PROGRESSES.

VICINITY OF KSFO...VFR. GUSTY WEST NORTHWESTERLY WINDS OF 20 TO 25
KNOTS SUSTAINED WITH GUSTS TO 32 KNOTS ARE EXPECTED THROUGH 0200Z.
WINDS WILL DIMINISH TO 15 KT BY 0200Z AND STEADILY DECREASE TO 5 KTS
THIS EVENING.

KSFO BRIDGE APPROACH...VFR.

MONTEREY BAY AREA TERMINALS...VFR. WEST NORTHWEST WINDS 5 KNOTS THIS
MORNING WILL GRADUALLY INCREASE TO 10 TO 15 KT BY 1600Z.

&&

.MARINE....AS OF 3:52 AM TUESDAY...A STRONG NORTHERLY SURFACE
PRESSURE GRADIENT WILL MAINTAIN STRONG GUSTY WINDS OVER THE COASTAL
WATERS THROUGH THIS EVENING. THE STRONGEST WINDS WILL BE IN THE
OUTER WATERS AND SOUTH OF COASTAL POINTS ALONG THE INNER COASTAL
WATERS. THESE STRONG WINDS WILL GENERATE STEEP FRESH SWELL ACROSS
THE COASTAL WATERS AND BOTH MONTEREY AND SAN FRANCISCO BAYS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDY...GALE...PT ARENA TO PT PIEDRAS BLANCAS 10 TO 60
         ...SCA....PT ARENA TO PT PIEDRAS BLANCAS 0 TO 10
         ...SCA....MONTEREY AND SAN FRANCISCO BAYS

&&

PUBLIC FORECAST: RILEY
AVIATION/MARINE: LARRY