000
FXUS66 KMTR 231154
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
454 AM PDT WED MAY 23 2012

...COOLER TEMPERATURES AND A POSSIBILITY OF PRECIPITATION FRIDAY...

.DISCUSSION...AS OF 3:15 AM PDT WEDNESDAY...THE CURRENT IR
SATELLITE FOG PRODUCT IS SHOWING STRATUS ALONG PORTIONS OF THE
COAST THIS EVENING WITH OVERCAST CEILINGS BEING REPORTED AT BOTH
HALF MOON BAY AND MONTEREY AIRPORT THIS MORNING. THE SATELLITE
WATER VAPOUR IMAGE IS SHOWING HIGH PRESSURE OVER THE EASTERN
PACIFIC WITH A LOW PRESSURE SYSTEM POSITIONED ALONG THE COAST OF
BRITISH COLUMBIA. THIS LOW PRESSURE SYSTEM WILL BE A BIG PLAYER IN
CENTRAL COAST WEATHER LATER THIS WEEK.

ANOTHER PLEASANT DAY IS EXPECTED ACROSS THE CWA TODAY WITH
AFTERNOON TEMPERATURES IN THE MID 60S TO LOW 70S ALONG THE COAST
AND MID TO UPPER 70S INLAND. LOW CLOUDS IN MONTEREY ARE EXPECTED
TO BURN OFF RELATIVELY QUICKLY THIS MORNING WITH A LITTLE HELP
FROM NORTHERLY WINDS MIXING DRY AIR DOWN FROM ALOFT. THE NORTHERLY
WINDS WILL BE BREEZY ON THE BEACHES THIS AFTERNOON SO YOU MAY WANT
TO TAKE A JACKET IF YOU ARE VISITING THE BEACHES. BREEZY
CONDITIONS ARE ALSO EXPECTED ALONG THE RIDGE LINES THIS
AFTERNOON...WHICH SHOULD PROMOTE DRYING OF THE ATMOSPHERE.

THE 0000Z RUNS OF THE ECMWF...GFS40 AND NAM12 ARE ALL IN GOOD
AGREEMENT WITH BRINGING THE PREVIOUSLY MENTIONED LOW PRESSURE
SYSTEM...WHICH IS CURRENTLY LOCATED ALONG THE BRITISH COLUMBIA
COAST... SOUTH INTO CALIFORNIA FRIDAY MORNING. THIS LOW PRESSURE
SYSTEM WILL RESULT IN A SUBSTANTIAL COOL DOWN FRIDAY WITH
AFTERNOON TEMPERATURES ONLY EXPECTED TO BE IN 60S...SOME ELEVATED AREAS
IN MONTEREY AND SAN BENITO COUNTIES WILL HAVE A HARD TIME GETTING
OUT OF THE UPPER 50S. FREEZING LEVELS WILL BE CLOSE TO 5000 FEET
ON FRIDAY.

THERE IS SOME MOISTURE ASSOCIATED WITH THIS SYSTEM WHICH WILL
RESULT IN A POSSIBILITY OF LIGHT SHOWERS. THE TEMPERATURE AT 500MB
WILL BE HOVERING AROUND -25 DEGREES CELSIUS SO CANT RULE OUT SOME
SMALL HAIL AND MAYBE A LIGHTNING STRIKE OR TWO. THE BEST
PROBABILITY OF SMALL HAIL AND LIGHTNING WOULD BE IN THE NORTH BAY
AREA FRIDAY AFTERNOON.

&&

.AVIATION...AS OF 4:50 AM PDT WEDNESDAY...MAINLY VFR CONDITIONS WILL
PREVAIL THROUGH THE FORECAST. PATCHY LOW CLOUDS WERE OBSERVED
THROUGH THE MONTEREY BAY AND SOUTH SF BAY...WITH TEMPO CIGS
EXPECTED THROUGH 16Z. MODERATE ONSHORE WINDS WILL CONTINUE
TODAY...WITH AN INCREASE IN SPEED EARLY THIS AFTERNOON. THE SFO-
SAC GRADIENT IS FORECAST TO INCREASE TO OVER +3.5 MB AGAIN THIS
AFTERNOON...RESULTING IN GUSTY WEST WINDS. OTHERWISE...A RETURN OF
STRATUS IS FORECAST EARLY MORNING THURSDAY...MAINLY OVER THE
MONTEREY BAY. LOW CONFIDENCE.

VICINITY OF KSFO...PATCHY IFR CIGS WILL BE POSSIBLE THROUGH 15Z.
LOW CONFIDENCE. WEST WINDS WILL INCREASE SIGNIFICANTLY EARLY THIS
AFTERNOON...WITH GUSTS OVER 30 KT POSSIBLE AT KSFO.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...PATCHY IFR CIGS WILL BE POSSIBLE
THROUGH 16Z. LOW CONFIDENCE. MODERATE WEST WINDS WILL BE PRESENT
AT BOTH KMRY AND KSNS THIS AFTERNOON INTO THE EARLY EVENING HOURS.
STRATUS IS FORECAST TO RETURN EARLY THURSDAY MORNING. LOW
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 ARENA TO PIGEON PT 10-60 NM
             GLW...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
             GLW...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
             SCA...ROUGH BAR ADVISORY FOR SF BAR FROM 11 AM
             SCA...MRY BAY
             SCA...SF BAY FROM 2 PM

&&

$$

PUBLIC FORECAST: LARRY
AVIATION/MARINE: RILEY