FXUS66 KMTR 050551
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
951 PM PST SAT FEB 4 2012

.DISCUSSION...AS OF 9:00 PM PST SATURDAY...A HIGH AMPLITUDE UPPER
RIDGE ALONG THE WEST COAST CONTINUES TO MAINTAIN DRY CONDITIONS
ACROSS THE FORECAST AREA. LACK OF HIGH CLOUD COVER TODAY RESULTED
IN A SLIGHT INCREASE IN HIGH TEMPERATURES TODAY COMPARED TO FRIDAY.
AFTERNOON HIGHS WERE MOSTLY IN THE 60S ACROSS THE REGION TODAY. SOME
LOCATIONS NEAR MONTEREY BAY REACHED INTO THE LOWER 70S...AS DID
SOME VALLEY LOCATIONS IN MONTEREY AND SAN BENITO COUNTIES.

MORE OF THE SAME IS FORECAST FOR THE SECOND HALF OF THE WEEKEND
AS THE UPPER RIDGE CONTINUES TO BLOCK INCOMING PACIFIC WEATHER
SYSTEMS...MAINTAINING DRY AND MILD WEATHER ACROSS CALIFORNIA. THE
RIDGE IS FORECAST TO BEGIN TO WEAKEN ON MONDAY AS A STRONG UPPER
JET APPROACHES FROM THE WEST. CLOUDS WILL BEGIN TO INCREASE
MONDAY AND TEMPERATURES WILL COOL SLIGHTLY.

CONFIDENCE IS INCREASING THAT A BRIEF PERIOD OF WET WEATHER WILL
OCCUR FROM LATE MONDAY NIGHT THROUGH TUESDAY. A RELATIVELY STRONG
WEATHER SYSTEM APPROACHING FROM THE WEST WILL SPLIT ON MONDAY AS
IT NEARS THE WEST COAST RIDGE. THE MODELS AGREE REASONABLY WELL IN
MAINTAINING A SUFFICIENT AMOUNT OF STRENGTH AND MOISTURE IN THE
SOUTHERN PART OF THE SPLIT TO UNDERCUT THE RIDGE AND SPREAD RAIN
ACROSS MOST...IF NOT ALL...OF OUR FORECAST AREA. BASED ON THE 00Z
NAM AND 00Z GFS...RAIN WILL BEGIN NEAR THE COAST A FEW HOURS PRIOR
TO SUNRISE TUESDAY MORNING AND THEN SPREAD EASTWARD ACROSS THE
REMAINDER OF OUR AREA BY MIDDAY TUESDAY. IMPACTS ON TUESDAY WILL
PRIMARILY BE TO THE MORNING COMMUTE WITH WET ROADWAYS AND GUSTY
WINDS EXPECTED. SOUTHERLY WINDS ON TUESDAY MORNING MAY GUST AS
HIGH AS 40 MPH NEAR THE COAST...IN THE HILLS...AND IN THE SALINAS
VALLEY. BOTH THE NAM AND GFS HAVE TRENDED WETTER WITH THEIR 00Z
RUNS AND SO A PERIOD OF AT LEAST MODERATE RAIN IS NOW EXPECTED
ON TUESDAY FROM SUNRISE THROUGH MID AFTERNOON. RAIN WILL THEN
TAPER OFF LATE IN THE DAY AND OVERNIGHT TUESDAY NIGHT AS THE
SYSTEM DROPS TO OUR SOUTH. RAINFALL AMOUNTS ARE EXPECTED TO MOSTLY
RANGE FROM 0.5 TO 1.5 INCHES...AND BE SPREAD RATHER UNIFORMLY
ACROSS OUR AREA. THE POTENTIAL FOR HEAVIER RAIN WILL BE GREATEST
OVER OUR SOUTHERN COASTAL MOUNTAINS...IN AN AREA CLOSEST TO WHERE
AN UPPER LOW IS FORECAST TO DEVELOP ON TUESDAY.

ANY RESIDUAL SHOWER ACTIVITY IS EXPECTED TO END BY WEDNESDAY
MORNING. UPPER RIDGING IS THEN FORECAST TO RAPIDLY REDEVELOP AND
PRODUCE MORE MILD AND DRY WEATHER FOR THE SECOND HALF OF THE WEEK.
THE MEDIUM RANGE MODELS HINT AT THE POSSIBILITY OF RAIN NEXT
WEEKEND...BUT THE SYSTEM APPROACHING THE WEST COAST NEXT WEEKEND
IS FORECAST TO WEAKEN RAPIDLY AS IT NEARS. IN FACT...THE LATEST
GFS AND ECMWF BOTH SHOW ALMOST NO RAINFALL NEXT WEEKEND AS THE
DISSIPATING WEATHER SYSTEM COMES ASHORE.

&&

.AVIATION...AS OF 9:48 PM PST SATURDAY...AIRMASS REMAINS DRY ENOUGH
TO MAINTAIN VFR FOR THE PERIOD.

VICINITY OF KSFO...VFR.

KSFO BRIDGE APPROACH....VFR.

MONTEREY BAY AREA TERMINALS...VFR.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...ROUGH BAR ADVISORY FOR SF BAR

&&

$$

PUBLIC FORECAST: DYKEMA
AVIATION/MARINE: CANEPA


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