000
FXUS66 KMTR 180243
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
743 PM PDT FRI MAY 17 2013

.DISCUSSION...AS OF 7:40 PM PDT FRIDAY...TEMPERATURES TODAY WERE
FOR THE MOST PART EITHER THE SAME OR A FEW DEGREES COOLER COMPARED
TO THURSDAY. GILROY AND MORGAN HILL WERE A COUPLE EXCEPTIONS TO
THIS WHERE GILROY PEAKED AT 78F COMPARED TO 68F YESTERDAY AND
MORGAN HILL`S MAX WAS 79F COMPARED TO 74F YESTERDAY.

LATE DAY VISIBLE SATELLITE IMAGERY SHOWS MOSTLY CLEAR TO CLEAR
SKIES ACROSS THE REGION. A FEW HIGH CLOUDS WERE DRIFTING IN FROM
THE NORTHWEST. OTHERWISE THE DRY WEATHER CONTINUES AS HIGH PRESSURE
BUILDS IN FROM THE WEST TONIGHT AND THROUGH FRIDAY. THE ONSHORE
PRESSURE GRADIENT FROM SFO-SAC IS 2-3 MB CAUSING LOCALLY GUSTY WEST
WINDS TO 29 KNOTS AT THE GOLDEN GATE AND WEST WINDS 25-30 KNOTS
THROUGH THE CARQUINEZ STRAIT.

DRY WITH A WARMING TREND IS WHAT IS EXPECTED THROUGH THE WEEKEND.
A VIGOROUS LOW WILL REACH THE PACIFIC NORTHWEST BY TUESDAY OF NEXT
WEEK WHICH WILL CAUSE THE RIDGE OVER NORTHERN CALIFORNIA TO WEAKEN.
THIS WILL MOST LIKELY INCREASE ONSHORE WINDS AS WELL. THE TROUGH
WILL BE TOO FAR TO THE NORTH TO BRING ANY MEASURABLE RAIN TO THE
AREA. WHEN THE LOW REACHES THE PACIFIC NORTHWEST IT WILL SLOW DOWN
CONSIDERABLY AND MEANDER THERE IN PLACE TIL LATE NEXT WEEK WHEN IT
BECOMES PART OF AN OMEGA BLOCK PATTERN AS A LARGE RIDGE AND ANOTHER
LOW DEVELOP DOWNSTREAM OVER THE MIDWESTERN AND NORTHEASTERN UNITED
STATES. AS MENTIONED NO MEASURABLE RAINFALL IS EXPECTED BUT THERE
WILL BE PLENTY OF SUPPORT FOR ONSHORE BREEZES EACH DAY LATE NEXT
WEEK AND THROUGH THE HOLIDAY WEEKEND.

&&

.AVIATION...AS OF 4:55 PM PDT FRIDAY...BRISK NORTHWEST WINDS MIXED
A DRIER AIRMASS INTO THE BOUNDARY LAYER THIS AFTERNOON AND NEARLY
ALL LOW CLOUDS HAD CLEARED...EVEN FROM COASTAL AREAS...BY LATE
AFTERNOON. INDICATIONS ARE THAT IT WILL TAKE A WHILE FOR THE LOW
LEVELS TO STABILIZE AND MOISTEN UP. THUS...LOW CIGS PROBABLY WON`T
DEVELOP UNTIL LATE TONIGHT...AND CERTAINLY AFTER THE EVENING RUSH.
LOW CLOUDS THAT DO DEVELOP LATE TONIGHT WILL PROBABLY BE IN A
RELATIVELY THIN LAYER...SO LOOK FOR EARLY CLEARING ON SATURDAY
MORNING. MODERATE AND GUSTY ONSHORE WINDS EARLY THIS EVENING AND
AGAIN ON SATURDAY AFTERNOON.

VICINITY OF KSFO...VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH
THE EVENING RUSH...WITH MVFR CIGS POSSIBLE BY ABOUT 09Z.
CONFIDENCE MODERATE. MVFR CIGS SHOULD CLEAR BY 16Z SATURDAY
MORNING. WEST WINDS 20G27KT EARLY THIS EVENING...GRADUALLY
DIMINISHING OVERNIGHT.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO EXCEPT LATER CIGS TONIGHT.

MONTEREY BAY AREA TERMINALS...MVFR CIGS WILL LIKELY RETURN
OVERNIGHT...BUT PROBABLY NOT UNTIL AFTER 06Z...AND THEN CLEAR BY
17Z SATURDAY MORNING.

&&

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

&&

$$

PUBLIC FORECAST: CANEPA
AVIATION/MARINE: DYKEMA

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