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000
FXUS66 KMTR 231144
AFDMTR

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

.DISCUSSION...AS OF 2:38 AM PDT THURSDAY...COOL TEMPERATURES AND
BREEZY CONDITIONS ARE EXPECTED ACROSS THE FORECAST AREA ONCE AGAIN
TODAY AS A RESULT OF A LOW PRESSURE SYSTEM CENTERED OVER THE
PACIFIC NORTHWEST. THIS LOW PRESSURE SYSTEM IS ADVECTING COOL
MARINE AIR INTO THE FORECAST AREA AND IS EXPECTED TO LINGER AROUND
THROUGH THE END OF THE WEEK.

AS PREVIOUSLY STATED A LOW PRESSURE SYSTEM IS CENTERED OVER THE
PACIFIC NORTHWEST THIS MORNING. ANOTHER LOW PRESSURE SYSTEM IN
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 4:44 AM PDT THURSDAY...FOR 12Z TAFS. GUSTY WEST
WINDS TO CONTINUE TO IMPACT MOST TERMINALS AGAIN TODAY BUT OVERALL
WIND SPEEDS FORECAST TO BE LIGHTER THAN PREVIOUS DAYS. EARLY
MORNING SATELLITE SHOWS LOW CLOUDS IMPACTING MONTEREY BAY REGION
AND THE SAN MATEO COAST AS WELL AS THE EAST BAY/SANTA CLARA VALLEY
HILLS. LOW CLOUDS ARE PILING UP ALONG THE HILLS IN BRISK ONSHORE
FLOW. GOOD NEWS IS THERE IS NO WELL DEFINED INVERSION LAYER AND
NOT EXPECTING CIGS TO IMPACT BAY AREA TERMINALS WITH ANY CIGS
BANKED UP AGAINST THE HILLS EXPECTED TO MIX OUT QUICKLY THIS
MORNING. LOW CLOUDS OVER KMRY AND KSNS EARLY THIS MORNING WILL MIX
OUT BY 16Z.

VICINITY OF KSFO...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...A FEW CLOUDS MAY PASS OVER THE
APPROACH BUT NO CIGS EXPECTED. SIMILAR TO KSFO BUT LIGHTER WINDS.

MONTEREY BAY AREA TERMINALS...SCT-BKN CIGS AT 1500-2000 FT
THROUGH 16Z THURSDAY...THEN CLEARING. GUSTY WEST WINDS THIS
AFTERNOON AND EVENING.

&&

.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: LARRY
AVIATION/MARINE: RWW

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