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000
FXUS66 KMTR 231813
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1113 AM PDT THU MAY 23 2013

.DISCUSSION...AS OF 9:00 AM PDT THURSDAY...PARTLY CLOUDY TO MOSTLY
CLOUDY SKIES WERE PRESENT THROUGH PARTS OF THE SOUTHERN HALF OF
THE REGION. MODERATE NORTH TO NORTHWEST WINDS WERE PRESENT OVER
THE AREA OVERNIGHT...WITH WIND GUSTS TO 20 MPH COMMON.
OTHERWISE...WITH MOSTLY CLEAR SKIES AND A COOL MASS...OVERNIGHT LOW
TEMPERATURES FELL INTO THE UPPER 30S TO 40S...AROUND 5 DEGREES
BELOW NORMAL FOR THE END OF MAY. A FEW SPOTS IN SOUTHERN MONTEREY
AND SAN BENITO COUNTIES ACTUALLY COOLED TO NEAR FREEZING...WITH
FORT HUNTER LIGGET IN SOUTHERN MONTEREY COUNTY DIPPING TO 33
DEGREES.

OTHERWISE...CURRENT FORECAST LOOKS RIGHT ON TRACK. THE MAIN FOCUS
OF THE FORECAST WILL CONTINUE TO BE THE POSSIBILITY OF RAIN FOR
THE AREA ON MEMORIAL DAY.

.PREVIOUS DISCUSSION...AS OF 2:38 AM PDT THURSDAY...AS PREVIOUSLY
STATED A LOW PRESSURE SYSTEM IS CENTERED OVER THE PACIFIC
NORTHWEST THIS MORNING. ANOTHER LOW PRESSURE SYSTEM IS APPARENT ON
THE CURRENT SATELLITE WATER VAPOUR IMAGE ENTERING THE BERING SEA.
BOTH THE 0000Z GFS AND ECMWF HAVE INITIALIZED WELL WITH THESE
FEATURES PUSHING THE PACIFIC NORTHWEST LOW NORTHEAST INTO CANADA
SATURDAY. BOTH MODELS CONTINUE TO DEPICT A COOL TROUGHY PATTERN
OVER OUR FORECAST AREA THROUGH THE WEEKEND. BOTH MODELS THEN
INTRODUCE A NEW TROUGH OF LOW PRESSURE MOVING TOWARDS THE WEST
COAST MONDAY BRINGING A POSSIBILITY OF RAIN TO NORTHERN PORTIONS
OF THE FORECAST AREA BY LATE MONDAY MORNING. AT THIS POINT IT
LOOKS LIKE RAIN WILL ARRIVE TO THE NORTH BAY AREA LATE MONDAY
MORNING SPREADING SOUTH TO SAN FRANCISCO BY LATE AFTERNOON AND
MONTEREY BY EARLY EVENING. KEEP IN MIND THAT THIS FORECAST IS
STILL SEVERAL DAYS OUT AND THE TIMING OF THE RAIN MAY CHANGE BY
MONDAY. BY MID WEEK THE FORECAST MODELS ARE DEPICTING A DIRTY
RIDGE SCENARIO WHICH WILL RESULT IN COOL ONSHORE FLOW AND POSSIBLY
A SHOWER OR TWO THROUGH THE END OF THE WORK WEEK.

&&

.AVIATION...AS OF 11:15 AM PDT THURSDAY...INTERESTING SATELLITE
IMAGE WITH MOSTLY CLEAR SKIES AT THE COAST AND POCKETS OF CLOUDS
INLAND. NORTHERLY GRADIENT STILL TWICE THE WESTERLY VALUES SO
WOULD EXPECT DISSIPATION TO CONTINUE WITH VFR CONDITIONS THIS
AFTERNOON AND EARLY EVENING IN ALL SPOTS. STILL BREEZY THIS
AFTERNOON WITH GUSTS OVER 25 KT POSSIBLE IN SPOTS. FOR TONIGHT THE
BIG QUESTION IS WILL CLOUDS ROLL IN AND DROP MOST PLACES DOWN TO
MVFR LEVELS. MODELS ARE SPLIT ON THE RETURN TO CLOUDS AND NORTHERLY
FLOW IS STILL EXPECTED TO BE STRONGER THAN THE FLOW FROM THE WEST.
FOR NOW...WILL HEDGE TOWARD CLIMATOLOGY AND BRING IN CIGS TONIGHT.
MODERATE CONFIDENCE.

VICINITY OF KSFO...GUSTY WEST TO NORTHWEST WINDS THROUGH THE DAY
WITH SPEEDS UP TO 30 KT POSSIBLE. 50-50 CHANCE OF CLOUDS RETURNING
TONIGHT BRINGING CIGS DOWN TO MVFR LEVELS. MODERATE CONFIDENCE.


FEW-SCT CLOUDS NEARBY EARLY THIS MORNING BUT
NOT EXPECTED TO IMPACT TERMINAL. GUSTY WEST WINDS CURRENTLY
GUSTING TO 30 KT WILL SUBSIDE FOR A TIME THIS MORNING BEFORE
INCREASING AGAIN THIS AFTERNOON.

KSFO BRIDGE APPROACH...VFR...SIMILAR TO KSFO BUT LIGHTER WINDS.

MONTEREY BAY AREA TERMINALS...CLOUDS VERY SLOW TO BURN BUT SHOULD
GO VFR FOR MOST OF THE AFTERNOON INTO THE EARLY EVENING. MVFR CIGS
EXPECTED TO RETURN TONIGHT. WESTERLY WINDS THROUGH THE PERIOD WITH
GUSTS TO 20 KT DURING THE AFTERNOON AND EARLY EVENING. MODERATE
CONFIDENCE.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 0-10 NM
             SCA...PT REYES TO PIGEON PT 0-10 NM
             SCA...PIGEON PT TO PT PINOS 0-10 NM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
             SCA...PT ARENA TO PIGEON PT 10-60 NM
             SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
             SCA...SF BAY FROM 1 PM
             SCA...MRY BAY FROM 1 PM

&&

$$

PUBLIC FORECAST: RILEY/LARRY
AVIATION/MARINE: BELL

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