000
FXUS66 KMTR 181056
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
356 AM PDT SAT MAY 18 2013

.DISCUSSION...AS OF 3:55 AM PDT SATURDAY...MAINLY CLEAR SKIES
PERSIST ACROSS THE REGION THIS MORNING WITH A FEW PATCHES OF LOW
CLOUDS PRESENT ACROSS THE SAN FRANCISCO AND MONTEREY BAY AREA.
CLOUD HEIGHTS ARE CURRENTLY AROUND 1500 FEET AND EXPECTED TO
RAPIDLY CLEAR AFTER SUNRISE.

HIGH PRESSURE BUILDING OVER THE EASTERN PACIFIC WILL MAINTAIN
MOSTLY CLEAR SKIES AND KICK START A WARMING TREND THAT WILL
PERSIST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. TEMPERATURES
ARE FORECAST TO GRADUALLY WARM TO ABOVE NORMAL ON SUNDAY THEN PEAK
ON MONDAY WITH HIGHS REACHING INTO THE 70S ALONG THE COAST AND 80S
TO LOWER 90S INLAND. UPPER 90S TO AROUND 100 EXPECTED IN THE
WARMEST INLAND AREAS.

LATEST OBSERVATIONS SHOW THE NORTHERLY GRADIENT FROM ACV TO SFO
HAS STRENGTHENED OVER A MB DURING THE LAST 24 HOURS AND CURRENTLY
STANDS AT 2.9 MB. AS THE HIGH OVER THE EASTERN PACIFIC BEGINS TO
RIDGES ACROSS THE PACIFIC NORTHWEST TODAY THEN SUBSEQUENTLY INTO
THE GREAT BASIN ON SUNDAY THE NORTHERLY GRADIENT WILL CONTINUE TO
STRENGTHEN AND WINDS WILL TURN INCREASINGLY TO THE NORTH WITH A
SLIGHT OFFSHORE COMPONENT. A SHORTWAVE SLIDING IN ACROSS OREGON
AND INTO THE GREAT BASIN WILL RESULT IN STRONG AND GUSTY WINDS
SUNDAY NIGHT...ESPECIALLY IN THE NORTH AND EAST BAY HILLS. MODELS
CONTINUE TO SHOW SUSTAINED 925 MB WINDS OF 25 TO 30 KT.

WARM TEMPERATURES...A DRIER AIRMASS AND WINDS WILL COMBINE ON
MONDAY TO RAISE FIRE WEATHER CONCERNS. THE SITUATIONS WILL
CONTINUE TO BE MONITORED CLOSELY THROUGH THE WEEKEND.

COOLER WEATHER IS IN STORE FROM TUESDAY ON AS A CUT OFF LOW MOVES
IN OVER THE PACIFIC NORTHWEST AND MEANDERS OVER THE AREA THROUGH
THE END OF THE WEEK. THIS SYSTEM WILL INTRODUCE A COOLER AIRMASS
TO THE REGION WHICH WILL DRIVE TEMPERATURES INTO THE 50S AT THE
COAST AND 60S AND 70S INLAND. TEMPERATURES WILL SEE THE GREATEST
DROP DURING THE SECOND HALF OF THE WEEK. MODELS HAVE BACKED OFF ON
BRINGING ANY PRECIP TO THE DISTRICT WITH PRECIP STAYING NORTH OF
THE CWA.

&&

.AVIATION...AS OF 10:40 PM PDT FRIDAY...DRIER AIR IN THE BOUNDARY
LAYER AND LACK OF A STRONG MARINE INVERSION HAS RESULTED IN MOSTLY
CLEAR SKIES ACROSS THE REGION THROUGH MUCH OF FRIDAY EVENING.
SATELLITE SHOWS PATCHES OF LOW CLOUDS HAD BEGUN TO FORM BY 06Z AND
EXPECT LOW CLOUDS TO GRADUALLY INCREASE THROUGH THE NIGHT AS THE
BOUNDARY LAYER STABILIZES. THIS SHOULD RESULT IN MVFR CIGS AT
MOST TERMINALS BY 12Z. LOW CLOUDS THAT DEVELOP LATE TONIGHT WILL
PROBABLY BE IN A RELATIVELY THIN LAYER...SO LOOK FOR EARLY
CLEARING ON SATURDAY MORNING. MODERATE AND GUSTY WESTERLY WINDS ARE
FORECAST TO DEVELOP SATURDAY AFTERNOON.

VICINITY OF KSFO...MVFR CIGS POSSIBLE BY ABOUT 10Z AND LIKELY BY
12Z. MVFR CIGS SHOULD CLEAR BY 16Z SATURDAY MORNING. CONFIDENCE
MODERATE. WEST WINDS INCREASING TO 24G30KT BY MID AFTERNOON
SATURDAY.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS WILL LIKELY DEVELOP BY
10Z...AND THEN CLEAR BY 17Z SATURDAY MORNING. WEST WINDS
INCREASING TO ABOUT 15 KNOTS ON SATURDAY AFTERNOON.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...MRY BAY FROM NOON
             SCA...PIGEON PT TO PT PINOS 0-10 NM FROM NOON
             SCA...PT ARENA TO PT REYES 0-10 NM
             SCA...PT REYES TO PIGEON PT 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 3 PM

&&

$$

PUBLIC FORECAST: CW
AVIATION/MARINE: DYKEMA

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