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

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000
FXUS66 KMTR 221619
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
919 AM PDT MON SEP 22 2014

.SYNOPSIS...TWO MORE DAYS OF NEAR NORMAL TEMPERATURES AND COASTAL
LOW CLOUDS IN STORE FOR THE FORECAST AREA. A PACIFIC STORM SYSTEM
WILL BRING RAIN TO OUR AREA BY MIDWEEK.

&&

.DISCUSSION...AS OF 09:15 AM PDT MONDAY...MADE A FEW MINOR CHANGES
TO THE FORECAST THIS MORNING WITH RESPECT TO CLOUD COVER BASED OFF
THE LATEST VISIBLE SATELLITE. SHOULD CONTINUE TO SEE THE STRATUS
BURN-OFF THROUGH THE MORNING HOURS AND GIVE WAY TO MOSTLY SUNNY
SKIES INLAND BY THIS AFTERNOON. OTHERWISE...THE FORECAST LOOKS ON
TRACK FOR TODAY AND WILL WORK ON THE DETAILS OF THE MIDWEEK
SYSTEM SET TO BRING RAINFALL TO THE REGION...ESPECIALLY ACROSS THE
NORTH BAY SOUTHWARD TO THE SANTA CRUZ MOUNTAINS.

&&

.PREV DISCUSSION...AS OF 3:00 AM MONDAY...UNLIKE THE PAST SEVERAL
DAYS THE OVERNIGHT SATELLITE PRODUCT IS A BIT DIFFERENT EARLY THIS
MORNING WITH PLENTY OF BREAKS OFF THE COAST AND CLOUDS IN THE BAYS
AND ADJACENT VALLEYS. LAST FEW FRAMES DO SHOW SOME FILLING IN FROM
THE WATERS SO WILL BE INTERESTING TO SEE HOW THINGS LOOK BY DAY
BREAK. COULD ACTUALLY SEE SUNRISE NEAR LOCAL BEACHES -- ESPECIALLY
FOR PARTS OF MONTEREY COUNTY SOUTH OF POINT SUR. TEMPERATURES WILL
BE SIMILAR TO YESTERDAY WITH HIGHS IN THE 60S TO MID 70S AT THE
COAST WITH MID 70S TO LOWER 80S IN MOST URBAN SPOTS. TUESDAY LOOKS
TO BE A NEAR REPEAT OF TODAY WITH LITTLE CHANGE IN THE SURFACE
PATTERN AND BOTH 500 MB HEIGHTS AND 850 MB TEMPS VIRTUALLY
UNCHANGED.

ALL ATTENTION CONTINUES TO FOCUS ON WEDNESDAY AND THURSDAY AS A
PACIFIC STORM SYSTEM WILL ADVANCE TO THE PACNW FIRST ON TUESDAY
THEN DOWN INTO THE NORTHERN HALF OF CALIFORNIA. RAIN WILL ENTER
NORTHERN CALIFORNIA EARLY ON WEDNESDAY AND THEN SPREAD TO THE
SOUTH THROUGH THE DAY. ALTHOUGH THERE REMAINS SOME DISAGREEMENT
BETWEEN THE SPEED AND COVERAGE OF THE RAIN, THERE IS OVERALL
FAIRLY GOOD AGREEMENT THAT THE ASSOCIATED COLD FRONT WILL ADVANCE
TO THE NORTH BAY WEDNESDAY AFTERNOON OR EVENING AND THEN CONTINUE
TO PROGRESS TO THE SOUTH AND EAST DURING THE OVERNIGHT HOURS AND
INTO THURSDAY. DUE TO THE RAIN AND CLOUDS TEMPERATURES WILL COOL
TO BELOW NORMAL VALUES INLAND BY THURSDAY.

THE EVENT IS STILL A FEW DAYS OUT, SO UNFORTUNATELY WE STILL HAVE
A LIMITED NUMBER OF MORE DETAILED MODELS FOR QPF ALTHOUGH GENERAL
INDICATIONS ARE MORE THAN HALF AN INCH COULD FALL BY THURSDAY
AFTERNOON OVER THE NORTH BAY WITH CLOSER TO .1" - .25" AROUND SF
BAY AS WELL AS THE SANTA CRUZ MOUNTAINS. OTHER SPOTS INCLUDING
THE SANTA CLARA VALLEY AND MONTEREY WILL LIKELY PICK UP LESS
RAINFALL. POSSIBLE THAT HIGHER AMOUNTS COULD OCCUR WITH PW
AMOUNTS FORECAST TO BE AS HIGH AS 1.65" WEDNESDAY NIGHT. MODELS
HAVE ALSO CONTINUED TO INDICATE SOME INSTABILITY ALOFT, SO ADDED
A SLIGHT CHANCE FOR THUNDERSTORMS AS WELL ESPECIALLY OVER THE
NORTHERN WATERS AND THE NORTH BAY. WITH NOTING THAT THE OVERALL
TREND OVER THE PAST COUPLE OF DAYS HAS BEEN FOR A STRONGER AND
WETTER SYSTEM.

THERE HAD BEEN A LARGE DISCREPANCY BETWEEN THE MODEL SOLUTIONS
FOR THURSDAY NIGHT INTO THE WEEKEND WHICH THANKFULLY SEEMS TO BE
RESOLVED. LATEST TRENDS ARE NOW MORE IN LINE WITH THE OPERATIONAL
ECMWF WHICH HAS THE LONGWAVE TROF OVERHEAD FOR A MUCH LONGER
PERIOD AS A RIDGE BUILDS ACROSS THE CENTRAL CONUS. THIS WILL
ALLOW US TO KEEP AT LEAST A CHANCE OF SHOWERS GOING ACROSS PART
OF OUR CWA INTO THE WEEKEND ALONG WITH TEMPERATURES GENERALLY
COOLER THAN NORMAL (ESPECIALLY FOR INLAND SPOTS).

LOOKING INTO NEXT WEEK, QUIET WEATHER RETURNS AS THE MAIN STORM
TRACK SHIFTS UP TO THE NORTH.

&&

.AVIATION...AS OF 4:22 AM PDT MONDAY...MARINE LAYER SITS AROUND 2K
FEET ON THE PROFILERS. STRATUS COVERAGE IS PRETTY SOLID THIS
MORNING AT ALL TERMINALS WITH THE EXCEPTION BEING KMRY. THAT BEING
SAID...FOLLOWING MODEL GUIDANCE AND THE STRATUS MODEL CLEARING
TIME WOULD BE CLOSE TO 18Z. MAINLY VFR THIS AFTERNOON. CONF HIGH.

VICINITY OF KSFO...MVFR CIGS 1200-1600 FT THROUGH 18Z.

KSFO BRIDGE APPROACH...SAME AS KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS THROUGH 18-19Z.

&&

.CLIMATE...AUTUMN OFFICIALLY BEGINS (AUTUMNAL EQUINOX) AT 7:29 PM
PDT TODAY.

&&

.MARINE...AS OF 09:15 AM PDT MONDAY...LIGHT TO MODERATE
NORTHWESTERLY WINDS WILL CONTINUE ALONG THE CENTRAL COAST AS HIGH
PRESSURE REMAINS OVER THE EASTERN PACIFIC. A COLD FRONT WILL WILL
MOVE THROUGH THE REGION MID WEEK BRINGING A CHANCE FOR SHOWERS AND
POSSIBLY THUNDERSTORMS. IN ADDITION...NORTHWEST SWELL WILL BUILD
AND IMPACT OUR AREA STARTING ON WEDNESDAY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...NONE.

$$

PUBLIC FORECAST: RGASS
AVIATION: MM
MARINE: AC

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