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

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000
FXUS66 KMTR 012054
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
154 PM PDT SUN MAY 1 2016

.SYNOPSIS....AFTER A WARM DAY TODAY COASTAL FOG AND LOW CLOUDS
WILL LIKELY RETURN BY LATE TODAY OR TONIGHT. SEASONABLE AND DRY
WEATHER IS FORECAST MONDAY AND TUESDAY. A WEATHER SYSTEM WILL
APPROACH CALIFORNIA BY THE MIDDLE OF THE WEEK...BRINGING A CHANCE
OF SHOWERS FROM LATE WEDNESDAY THROUGH THE END OF THE WEEK...ALONG
WITH COOLER THAN NORMAL TEMPERATURES.

&&

.DISCUSSION...AS OF 2:00 PM PDT SUNDAY...WARM DAY ACROSS OUR
ENTIRE REGION TODAY WITH MOST SPOTS 3 TO 7 DEGREES AHEAD OF
YESTERDAY. MODELS HAD BEEN HIGHLIGHTING THE WARM READINGS FOR
NEARLY A WEEK AND APPEAR TO HAVE DONE A GOOD JOB WITH THE VALUES.
A FEW SPOTS HAVE SEEN VERY IMPRESSIVE INCREASES FROM YESTERDAY. IN
PARTICULAR MONTEREY WHERE 79 DEGREES HAS NOW BEEN REACHED. THAT IS
17 AHEAD OF YESTERDAY.

A COOL DOWN IS STILL ON TRACK STARTING TOMORROW AS THE OFFSHORE
FLOW FLIPS TO MORE ONSHORE. AT THE SAME TIME CLOUDS WILL MOVE
BACK INTO THE PICTURE AND RETURN TO COASTAL SPOTS PLUS SOME
ADJACENT VALLEYS TONIGHT. SATELLITE ALREADY SHOWS THE CHANGE WITH
A MINOR SOUTHERLY SURGE CURRENTLY TAKING PLACE. VISIBLE IMAGE HAVE
A NARROW BAND OF CLOUDS NOW INTO WESTERN MONTEREY BAY. THESE
CLOUDS SHOULD CONTINUE TO ADVANCE NORTH AND EAST OVERNIGHT.

WITH AN ONSHORE FLOW IN PLACE FOR MONDAY AND TUESDAY COASTAL
CLOUDS CAN BE EXPECTED ALONG WITH COOLER TEMPERATURES. MOST SPOTS
WILL SEE A 5 TO 10 DEGREE DROP IN HIGHS COMPARED TO TODAY ALTHOUGH
LOCATIONS WELL INLAND WILL SEE ONLY MINOR CHANGES.

UNSETTLED WEATHER WILL RETURN TO OUR REGION STARTING ON WEDNESDAY
AS A LONGWAVE TROF MOVES TO THE WEST COAST. MODELS INDICATE THAT A
CUT-OFF LOW WILL THEN FORM BY THURSDAY NEAR OUR COAST BEFORE
SLOWLY ADVANCING TO THE EAST. AS IS ALWAYS THE CASE WITH CUT-OFF
LOWS, CONFIDENCE IS FAIRLY LOW WITH THE TRACK AND LOCATION OF THE
CENTER WHICH MAKES PIN-POINTING THE BEST CHANCE FOR MOISTURE
DIFFICULT. FOR NOW WENT WITH A MORE GENERAL CHANCE OF SHOWERS. IN
ADDITION, A SLIGHT CHANCED OF THUNDERSTORMS WAS ADDED DUE TO THE
LOCATION OF THE TROF/LOW PLUS MORE INSTABILITY (NAM ALREADY
SHOWING LIFTED VALUES TO MINUS 2 OVER THE NORTH BAY). THIS TIME
OF YEAR, COLDER SYSTEMS COMING FROM THE NORTH ARE A GOOD BET FOR
PRODUCING SOME LIGHTING AND/OR SMALL HAIL. COOLER TEMPERATURES CAN
ALSO BE EXPECTED WITH HIGHS OF ONLY UPPER 50S TO UPPER 60S FOR
THURSDAY AND FRIDAY. DEPENDING ON THE TRACK OF THE LOW, THERE MAY
BE ONLY A LIMITED INCREASE IN TEMPS SATURDAY.

LONGER RANGE FORECAST FOR NEXT WEEK FAVORS A RETURN TO WARMER
THAN NORMAL CONDITIONS WITH NEAR TO SLIGHTLY BELOW NORMAL
PRECIPITATION.

&&

.AVIATION...AS OF 10:30 AM PDT SUNDAY...DRY OFFSHORE FLOW KEEPING
VFR TODAY. THE ONE FLY IN THE OINTMENT IN THE FORECAST IS A
POSSIBLE SOUTHERLY SURGE LATER TODAY. LATEST NAM AND WRF SHOW A
SOUTHERLY SURGE IMPACTING KMRY/KSNS...POSS MAKING IT INTO SF BAY
OVERNIGHT. CONF IS MARGINAL.

VICINITY OF KSFO...VFR.

SFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY TERMINALS...VFR BECOMING MVFR LATE THIS EVENING AND
OVERNIGHT.

&&

.MARINE...AS OF 01:22 PM PDT SUNDAY...HIGH PRESSURE OVER THE
EASTERN PACIFIC WILL KEEP NORTHERLY WINDS OVER THE COASTAL WATERS
TODAY. LOCALLY GUSTY WINDS WILL BE POSSIBLE OVER THE OUTER WATERS
NORTH OF POINT REYES. SOUTHERLY WINDS WILL DEVELOP LATE TONIGHT
AND EARLY MONDAY. A MODERATE SWELL WILL MIX WITH A SMALLER LONG
PERIOD SOUTHERLY SWELL THIS WEEK.

&&

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

$$

PUBLIC FORECAST: BELL
AVIATION: SIMS
MARINE: SIMS


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