000
FXUS66 KMTR 161138
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
438 AM PDT WED MAY 16 2012

.DISCUSSION...AS OF 3:15 AM PDT WEDNESDAY...HIGH PRESSURE WAS
CENTERED RIGHT ALONG THE COAST. THE FT ORD PROFILER IS INDC THAT
TEMPS ALOFT HAVE WARMED SIGNIFICANTLY...AS MUCH AS 13C AT 3500 FT
ASL. THE FT ORD PROFILER IS INDC THAT THE MARINE INVERSION IS
AROUND 1200 FT ASL...AND THE LATEST GOES WEST FOG DEPTH IMAGERY IS
INDC THAT THE DEPTH OF THE LOW CLOUDS IS BETWEEN 1000-1100 FT.

TEMPS THIS MORNING RANGE FROM THE 40S AND 50S IN THE MARINE
LAYER...TO THE UPPER 60S ALONG THE HIGHER PEAKS SUCH AS MT
DIABLO...WHICH MATCHES WHAT THE FT ORD PROFILER IS INDC. THE
LATEST GRADIENT PICTURE IS INDC A WEAK NORTHERLY GRADIENT OF 1.2
MB BETWEEN ARCATA-SFO AND A GOOD ONSHORE GRADIENT OF 2.3 MB
BETWEEN SFO-SAC. THIS GOOD ONSHORE GRADIENT HAS ALLOWED LOW CLOUDS
TO SURGE INLAND THIS EARLY MORNING...EVEN INTO THE EAST BAY
VALLEYS SUCH AS LIVERMORE.

TODAY WILL BE ANOTHER TYPICAL LATE SPRING DAY WITH COOL TEMPS
ALONG THE COAST AND WARM TEMPS INLAND. TEMPS WILL BE SIGNIFICANTLY
COOLER ON THURSDAY AS A STRONG...BUT DRY...MID LEVEL TROUGH MOVES
INTO THE DISTRICT. WITH MOST OF THE DEEP MOISTURE REMAINING TO THE
NORTH AND EAST WOULD NOT EXPECT ANY SHOWERS WITH THIS SYSTEM. THE
MARINE LAYER SHOULD MIX OUT THURSDAY AFTN AND EVENING WITH THE
COMBINATION OF COLD AIR ADVECTION AND BREEZY CONDITIONS.

AS THE TROUGH MOVES TO THE EAST A RELATIVELY FLAT RIDGE WILL BUILD
IN FROM THE PACIFIC. THIS WILL RESULT IN A SLOW WARMING TREND
BEGINNING ON FRIDAY AND CONTINUING THROUGH THE WEEKEND. COOLER
TEMPS COULD RETURN THE BEGINNING OF NEXT WEEK AS ANOTHER DRY MID
LEVEL TROUGH MOVES INTO THE DISTRICT.

&&

.AVIATION...AS OF 4:30 AM PDT WEDNESDAY...TYPICAL STRATUS DAY WITH ONSHORE
FLOW AT THE SURFACE AND VERY MINOR FORCING IN THE UPPER LEVELS
AS THE UPPER LEVEL RIDGE MOVES EAST.

VICINITY OF KSFO...IFR CIGS IMPROVING TO MVFR CIGS AFTER 17Z.
CLEARING EXPECTED BY 1830Z WHICH IS IN AGREEMENT WITH THE EARLY
RUNS OF THE CONSENSUS MODELS.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...IFR CIGS CLEARING AFTER 18Z.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 0-10 NM FROM 3 PM
             SCA...PT ARENA TO PIGEON PT 10-60 NM FROM 3 PM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
             SCA...SF BAY FROM 1 PM
             SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 9 AM

&&

$$

PUBLIC FORECAST: STROBIN
AVIATION/MARINE: W PI

NWS MTR Office Area Forecast Discussion