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

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000
FXUS66 KMTR 282227
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
327 PM PDT SUN JUN 28 2015

.SYNOPSIS...SOME MID LEVEL MOISTURE MAY MOVE INTO THE CENTRAL
COAST BY MONDAY MORNING AND THEN SPREAD NORTHWARD OVER THE BAY
AREA BY MONDAY AFTERNOON AND EVENING. THERE WILL BE ABOUT A
10 TO 20 PERCENT CHANCE OF A SHOWER OR ISOLATED
THUNDERSTORM...MAINLY FOR AREAS SOUTH OF SAN JOSE. THE MAIN
WEATHER STORY WILL BE A WARMING TREND STARTING MONDAY AND LASTING
AT LEAST THROUGH MIDWEEK WHEN INLAND AREAS WILL WARM WELL INTO THE
90S AND LOWER 100S.

&&

.DISCUSSION...AS OF 3:27 PM PDT SUNDAY...PARTLY CLOUDY CONDITIONS
THIS EVENING WITH SOME MARINE CLOUDS ALONG THE COAST AND SCATTERED
HIGH CLOUDS INLAND. SHORT TERM FORECAST ISSUE WILL BE TO MONITOR
AREA OF CLOUDS OVER FAR SOUTHERN CALIFORNIA. NAM MODEL INDICATES
MOISTURE MAY WORK NORTHWARD TOWARDS MONTEREY COUNTY BY EARLY
MORNING. HAVE INTRODUCED 15 PERCENT CHANCE OF SHOWERS AND ISOLATED
THUNDERSTORMS OVER THE SOUTHERN ZONES MONDAY MORNING...WORKING
NORTHWARD BY MONDAY AFTERNOON AND EARLY EVENING OVER THE SOUTH BAY
REGION. CONFIDENCE IS LOW BUT WILL HONOR THE LAST TWO RUNS OF THE
NAM THAT SHOW SOME INSTABILITY AND MOISTURE. OTHERWISE HIGH
PRESSURE WILL BEGIN TO REBUILD WITH A WARMING TREND RETURNING TO
THE REGION.

BY TUESDAY ANY PRECIP CHANCES APPEARS TO END AS HIGH PRESSURE
REBUILDS. LATEST RUNS SHOW A STRONG RIDGE BUILDING OVER THE DESERT
AND SPREADING WESTWARD. EXPECT TO SEE WIDESPREAD 90S AND SOME
TRIPLE DIGIT HEAT FOR ALL THE INLAND VALLEYS OF THE BAY AREA AND
CENTRAL COAST. HOT INLAND WEATHER WILL LAST AT LEAST THROUGH
MIDWEEK.

THE GFS MORESO THAN THE ECMWF SHOWS SOME MORE MOIST SOUTHEAST FLOW
BY LATER IN THE WEEK. WILL KEEP FORECAST DRY FOR NOW AND MONITOR
THESE SUBTLE LONG RANGE TRENDS. IN GENERAL LOOKS SEASONABLY HOT
INLAND WITH COOLER MARINE INFLUENCED AIR NEAR THE COAST.
EVENTUALLY WE SHOULD NOT BE SURPRISED IF ONE OF THE WAVES FROM THE
SOUTHEAST BRINGS SOME CONVECTIVE PRECIP TO OUR CWA THIS WEEK.

&&

.AVIATION...AS OF 11:00 AM PDT SUNDAY... SOMEWHAT CHALLENGING
MORNING WITH HIGH PRESSURE ROTATING IN HIGH LEVEL CLOUDS FROM THE
SOUTHEAST... AND UPPER LOW TO THE NORTHWEST. SATELLITE IMAGERY
SHOWS COASTAL STRATUS BANKED ALONG THE COAST THIS MORNING AS WELL
AS PERMEATING MARGINALLY INLAND ALONG COASTAL COMMUNITIES.
FORECAST FOR THE DAY WILL BE WIDESPREAD VFR WITH A FEW LINGERING
LOW CLOUDS FOR MARINE INFLUENCED TAF SITES AND A FEW TO SCT HIGH
CLOUDS ASSOCIATED WITH GREAT BASIN HIGH. ONSHORE WINDS CONT THIS
AFTERNOON WITH SPEEDS 10 TO 15 KT... GUSTS 20 TO 25 KT. MVFR/IFR
CIGS RETURN TONIGHT... WITH A FEW LOCATIONS POSSIBLY SEEING BRIEF
LIFR CONDS BTWN 12-16Z MON.

VICINITY OF KSFO... VFR TODAY. SLUGGISH MIX OUT THIS MORNING WITH
INTERACTION BETWEEN UPPER LEVEL SYSTEM AND LOW LEVEL MOISTURE
CURRENTLY RESULTING IN VARYING BANDS OF FEW TO SCT CLDS BTWN 1-2K
FT AGL. MAIN ISSUE WITH ENROUTE FLIGHTS WILL BE WITH APPROACH
VISUALS THRU 1830-19Z. ONSHORE FLOW AOA 15 KT WITH GSTS TO LOW 20S
POSBL. MVFR CIGS RETURN AOA 04Z.

KSFO BRIDGE APPROACH... APPROACH VISUALS MAY BE INTERRUPTED BY
INTERMITTENT DIRTY CIGS BTWN 1-2K AGL BTWN SAN MATEO BRIDGE AND
TERMINAL. SAT TRENDS ENCOURAGING AND EXPECT TO SEE VFR BTWN
1830-19Z.  OTHERWISE... SAME AS SFO.

MONTEREY BAY AREA TERMINALS... SAT TRENDS SHOW VERY SLOW MIXOUT
ALONG COASTLINE AND INLAND MONTEREY BAY NR KWVI... EXPECT
TRANSITION FROM MVFR TO VF BTWN 18-19Z. ONSHORE WINDS AOA 12KT
WITH GSTS TO 18KT. MVFR/IFR CIGS RETURN 02-04Z MON.

&&

.MARINE...AS OF 03:13 PM PDT SUNDAY...WINDS WILL BEGIN TO SHIFT TO
THE NORTHWEST AND STRENGTHEN TONIGHT AND INTO TOMORROW AS HIGH
PRESSURE REBUILDS INTO THE REGION. NORTHWEST SWELL WILL PERSIST
THROUGH THE PERIOD WITH A BRIEF PERIOD OF BUILDING SEAS EARLY THIS
WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 2 AM
             SCA...SF BAY UNTIL 9 PM

&&

$$

PUBLIC FORECAST: RWW
AVIATION: DRP
MARINE: DRP


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