Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA

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000
FXUS66 KMTR 080513
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1013 PM PDT TUE JUL 7 2015

.SYNOPSIS...SEASONALLY COOL TEMPERATURES ARE EXPECTED FOR MUCH OF
THE FORECAST AREA THROUGH THE WEEKEND...AS A LOW PRESSURE SYSTEM
SLIDES ACROSS CENTRAL AND NORTHERN CALIFORNIA. THIS LOW WILL ALSO
PROMOTE THE POSSIBILITY OF SHOWERS AND ISOLATED THUNDERSTORMS ON
WEDNESDAY AND THURSDAY.

&&

.DISCUSSION...AS OF 9:07 PM PDT TUESDAY...TODAY WAS A BEAUTIFUL
DAY AROUND THE AREA WITH PARTLY TO MOSTLY SUNNY SKIES FOR MOST AND
AFTERNOON HIGH TEMPERATURES IN THE LOW TO MID 70S ALONG THE COAST
AND LOW TO MID 80S INLAND. THE CURRENT SATELLITE WATER VAPOUR
IMAGE IS SHOWING A LOW PRESSURE SYSTEM POSITIONED JUST OFF SHORE
THIS EVENING...PROVIDING GENTLE ONSHORE FLOW WHICH WILL MODERATE
OVERNIGHT TEMPERATURES AND MOST LIKELY PUSH SOME MARINE CLOUDS
INTO LOW LYING AREAS ALONG THE COAST AND POSSIBLY THE INLAND
VALLEYS.

THE 1200Z ECMWF AND 0000Z GFS40 HAVE INITIALIZED WELL WITH THE
CURRENT SYNOPTIC WEATHER PATTERN AND REMAIN IN GOOD AGREEMENT
THROUGH THE FORECAST PERIOD. THE PREVIOUSLY MENTIONED LOW PRESSURE
SYSTEM WILL BE THE MAIN WEATHER PLAYER OVER THE NEXT FEW DAYS AS
IT SLOWLY SLIDES EAST ACROSS THE FORECAST AREA. AS THE LOW MOVES
INLAND WEDNESDAY EXPECT INCREASING CLOUDINESS...SEASONALLY COOL
BUT COMFORTABLE TEMPERATURES AND EVEN A POSSIBILITY OF SHOWERS AND
ISOLATED THUNDERSTORMS THROUGH THURSDAY EVENING.

THE LOW WILL EXIT THE AREA BY FRIDAY BRINGING AN END TO THE THREAT
OF SHOWERS AND THUNDERSTORMS FOR OUR AREA. HOWEVER...AS THE LOW
LEAVES THE AREA A TROUGH OF LOW PRESSURE PUSHES TOWARDS THE
PACIFIC NORTHWEST WHICH WILL REINFORCE SEASONALLY COOL TEMPERATURES
AROUND THE FORECAST AREA THROUGH THE WEEKEND. THE CURRENT FORECAST
PACKAGE SEEMS REASONABLE SO NO FURTHER UPDATES ARE NEEDED AT THIS
TIME.

&&

.AVIATION...AS OF 10:07 PM PDT TUESDAY...UPPER LOW OVER THE EPAC
WILL DRIFT EAST REACHING THE MONTEREY BAY AREA WEDNESDAY. COASTAL
CLOUDS ARE REDEVELOPING THIS EVENING.

VICINITY OF KSFO...MVFR CIG REDEVELOPING AT THE PRESENT TIME. MVFR
CIGS TIL 18Z. VFR IS EXPECTED TO RETURN BY MID-LATE WEDNESDAY MORNING.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR HOLDING TOGETHER SO FAR...BUT
EXPECTING CLOUDS TO INCREASE OVERNIGHT. TEMPO IFR INDICATED
06Z-08Z WITH IFR PREVAILING OVERNIGHT. VFR IS FORECAST TO RETURN
BY LATE WEDNESDAY MORNING.

&&

.MARINE...AS OF 8:57 PM PDT TUESDAY...LIGHT WINDS AND SMALL SEAS
WILL CONTINUE OVER THE COASTAL WATERS AS A WEAK LOW PRESSURE
REMAINS OFF THE COAST. WINDS WILL BE GUSTY EACH AFTERNOON IN BOTH
BAYS WITH DECENT ONSHORE FLOW. A SLIGHT CHANCE FOR THUNDERSTORMS
WILL BE POSSIBLE ON THURSDAY AS THE LOW PRESSURE SYSTEM MOVES
INLAND.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...NONE.

&&

$$

PUBLIC FORECAST: LARRY
AVIATION: CANEPA
MARINE: MM


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