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

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FXUS66 KMTR 021153
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
453 AM PDT MON MAY 2 2016

.SYNOPSIS....DRY AND SEASONABLE WEATHER IS FORECAST THROUGH
TOMORROW ALONG WITH COASTAL CLOUDS. A WEATHER SYSTEM WILL
APPROACH CALIFORNIA BY THE MIDDLE OF THE WEEK...BRINGING A CHANCE
OF SHOWERS AND A FEW THUNDERSTORMS BEGINNING WEDNESDAY LASTING
INTO THE WEEKEND...ALONG WITH COOLER THAN NORMAL TEMPERATURES.

&&

.DISCUSSION...AS OF 3:00 AM PDT MONDAY...AS EXPECTED CLOUDS
RETURNED TO THE COAST YESTERDAY EVENING AND BASED OFF OF THE
SATELLITE FOG PRODUCT, THEY HAVE CONTINUED FOR THE OVERNIGHT HOURS
AND HAVE ALSO SPREAD INTO SOME ADJACENT VALLEY SPOTS. AFTER A WARM
WARM DAY YESTERDAY, SUBSTANTIAL COOLING CAN BE EXPECTED TODAY AS
MORE OF AN ONSHORE FLOW WILL BRING AIR OFF THE WATER AND ACROSS
OUR REGION. FOR SOME COASTAL SPOTS HIGHS TODAY WILL BE 10 OR MORE
DEGREES UNDER THE VALUES FROM SUNDAY. FARTHER INLAND, THE DROP IN
TEMPS WILL BE LESS ALTHOUGH MOST LOCATIONS WILL SEE AT LEAST A 3
TO 6 DEGREE DECREASE. TONIGHT SHOULD BE A REPEAT OF TODAY WITH
CLOUDS RETURNING TO THE COAST PLUS ADJACENT VALLEY LOCATIONS.

AFTER A QUIET DAY ON TUESDAY UNSETTLED WEATHER RETURNS STARTING
ON WEDNESDAY AS A LONGWAVE TROF NEARS THE COAST WHILE AN UPPER
LEVEL CUT-OFF LOW FORMS AT THE BASE OF THE TROF NEAR OUR CWA.
BEYOND THAT POINT, MODELS ARE IN FAIRLY GOOD AGREEMENT THAT THE
LOW WILL VERY SLOWLY PROGRESS TO THE SOUTHEAST FOR THE REMAINDER
OF THE WEEK. WHERE THERE IS MORE DISAGREEMENT IS THE LOCATION OF
THE LOW PLUS THE MOST FAVORABLE LOCATIONS FOR ASSOCIATED MOISTURE
(ESPECIALLY WRAP-AROUND MOISTURE). THEREFORE, DECIDED TO KEEP
MOST SPOTS IN THE 20-30% CHANCE OF PRECIP FOR THE PERIOD. IN
ADDITION, BASED ON THE TRACK OF THE LOW PLUS GUIDANCE OUT TO 84
HOURS OFF THE NAM, KEPT A MENTION OF A SLIGHT CHANCE FOR T-STORMS
AND POSSIBLE SMALL HAIL. RAINFALL AMOUNTS WILL LIKELY BE MINOR
THROUGH THE PERIOD. COOLER TEMPS CAN ALSO BE EXPECTED -- MOSTLY
UPPER 50S TO UPPER 60S.

A RIDGE WILL BUILD IN BEHIND THE DEPARTING LOW FOR NEXT WEEK. THIS
WILL LEAD TO WARMER CONDITIONS ALONG WITH LITTLE TO NO RAIN.
&&

.AVIATION...AS OF 4:46 AM PDT MONDAY...TRICKY FORECAST THIS
MORNING AS SOUTHERLY SURGE IS STILL IN EFFECT OVER THE REGION. THE
TYPICAL SPOTS WITH SOUTHERLY SURGES HAVE CIGS...MRY/SNS/STS.
HOWEVER...CLOUDS INSIDE SF BAY ARE SPOTTY. BASED ON LATEST
GUIDANCE AND TRENDS WILL KEEP CIGS IN SF BAY MORE LIMITED. KSJC IS
ALSO TRICKY AS CLOUDS ARE SLOWLY APPROACHING FROM THE SOUTH. VFR
THIS AFTERNOON FOR ALL AIRPORTS...BUT CIGS RETURN TONIGHT.

VICINITY OF KSFO...WILL HAVE TO KEEP A CLOSE EYE ON SFO...BUT CONF
FOR CIGS DEVELOPMENT IS LOW. FOR NOW...WILL KEEP VFR CONDITIONS AT
KSFO AND KOAK. MVFR CIGS DEVELOP TONIGHT.

SFO BRIDGE APPROACH...A SLIGHTLY HIGHER CHANCE FOR CIG
DEVELOPMENT...ESPECIALLY SOUTH OF THE APPROACH.

MONTEREY BAY TERMINALS...MVFR/IFR CIGS THROUGH 17Z. VFR THIS
AFTERNOON. MVFR/IFR CIGS RETURN TONIGHT.

&&

.MARINE...AS OF 04:45 AM PDT MONDAY...A SOUTHERLY SURGE WILL
CONTINUE TO MOVE UP THE NORTHERN CALIFORNIA COAST KEEPING
SOUTHERLY WINDS IN PLACE TODAY. WINDS WILL GRADUALLY BECOME
NORTHERLY TONIGHT AND TUESDAY. A MODERATE SWELL WILL MIX WITH A
SMALLER LONG PERIOD SOUTHERLY SWELL THIS WEEK.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY

&&

$$

PUBLIC FORECAST: BELL
AVIATION: MM
MARINE: MM


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