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

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000
FXUS66 KMTR 251557
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
857 AM PDT MON MAY 25 2015

.SYNOPSIS...COOLER THAN NORMAL WEATHER...ALONG WITH WIDESPREAD
NIGHT AND MORNING LOW CLOUDS...WILL CONTINUE THROUGH TUESDAY. WARMER
CONDITIONS ARE EXPECTED DURING THE SECOND HALF OF THE
WEEK...ESPECIALLY FOR INLAND AREAS. HOWEVER...COASTAL AREAS WILL
REMAIN SEASONABLY COOL AS ONSHORE FLOW PERSISTS.

&&

.DISCUSSION...AS OF 9:00 AM PDT MONDAY...WIDESPREAD CLOUDS THIS
MORNING ACROSS ALMOST ALL OF OUR CWA. IN FACT...COMPARED TO
YESTERDAY THE CLOUDS EXTEND FARTHER INLAND AND OT THE NORTH.
INTERESTING TO NOTE THAT AROUND COASTAL MONTEREY COUNTY SOME
BREAKS ARE NOTED IN THE OVERALL FLOW SO QUITE POSSIBLE THAT SOME
COASTAL SPOTS THERE COULD SEE SUNSHINE BEFORE SAN JOSE OR EVEN
THE FAR INLAND EAST BAY AREAS. DUE TO THE CLOUDS...MARINE LAYER
OVER 3000 FEET...PLUS MODERATE ONSHORE FLOW AT THE SURFACE
TEMPERATURES WILL REMAIN COOLER THAN NORMAL. HIGHS WILL MOSTLY BE
UPPER 50S TO MID 60S AT THE COAST WITH UPPER 60S TO MID 70S FOR
MOST INLAND SPOTS.

MODELS CONTINUE TO BRING A RIDGE OF HIGH PRESSURE BACK TO OUR AREA
LATER THIS WEEK ALONG WITH MUCH WARMER 850MB TEMPS. HIGHS WILL
JUMP BACK INTO THE 80S FOR MANY INLAND LOCATIONS ESPECIALLY BY FRIDAY.
COASTAL AREAS WILL SEE ONLY LIMITED WARMING AS THE FLOW OFF THE
COOL OCEAN WATER WILL KEEP THE HOTTER WEATHER AT BAY.

.PREVIOUS DISCUSSION...COOLER THAN NORMAL WEATHER CONDITIONS...WHICH HAVE
PERSISTED ACROSS THE SAN FRANCISCO BAY AREA AND MONTEREY BAY AREA
FOR THE PAST THREE WEEKS...WILL CONTINUE FOR AT LEAST A FEW MORE
DAYS. ALTHOUGH AN UPPER RIDGE HAS DEVELOPED OFFSHORE ALONG
135W...AN UPPER LOW IS SETTLING INTO THE PAC NW AND HELPING TO
MAINTAIN A DEEP MARINE LAYER ACROSS OUR AREA. AND...COOL MARINE
AIR IS FLOWING WELL INLAND THANKS TO A PERSISTENT ONSHORE FLOW.

LITTLE CHANGE IS EXPECTED THROUGH TUESDAY. WIDESPREAD NIGHT AND
MORNING LOW CLOUDS WILL PERSIST...ALONG WITH PATCHY DRIZZLE NEAR
THE OCEAN. DAYTIME TEMPERATURES WILL REMAIN IN THE UPPER 50S ALONG
THE IMMEDIATE COAST WHERE LITTLE OR NO AFTERNOON SUN IS EXPECTED.
AFTERNOON CLEARING IS EXPECTED INLAND...BUT HIGH TEMPERATURES WILL
CONTINUE TO BE AT LEAST FIVE DEGREES BELOW NORMAL IN MOST
LOCATIONS.

THE MODELS HAVE BEEN CONSISTENT IN MOVING THE UPPER RIDGE TO THE
EAST BY MIDWEEK...WITH THE RIDGE AXIS POSITION FORECAST TO BE OVER
THE WEST COAST BY LATE THURSDAY. AS THE RIDGE BUILDS OVER CA
DURING THE SECOND HALF OF THE WEEK...LOOK FOR THE MARINE LAYER TO
BE COMPRESSED AND TEMPERATURES TO RISE...ESPECIALLY INLAND...AS
THE AIRMASS WARMS ALOFT AND MARINE AIR INFLUENCE DWINDLES. INLAND
TEMPERATURES ARE FORECAST TO RISE A FEW DEGREES ABOVE NORMAL BY
THURSDAY AND FRIDAY WHEN 80S WILL FINALLY RETURN TO LOCATIONS LIKE
LIVERMORE...GILROY AND CALISTOGA. A SHALLOW...BUT
PERSISTENT...MARINE LAYER ALONG WITH CONTINUED ONSHORE FLOW WILL
MEAN THE COASTAL STRIP WILL SEE MUCH LESS WARMING COMPARED TO
INLAND AREAS LATER THIS WEEK.

WARM CONDITIONS WILL CONTINUE INTO AT LEAST THE FIRST PART OF NEXT
WEEKEND. BUT THE RIDGE IS FORECAST TO MOVE EASTWARD OVER THE
WEEKEND AS A TROUGH APPROACHES THE WEST COAST. THIS WILL MEAN
COOLER CONDITIONS BY SUNDAY.

OTHER THAN PATCHY LATE NIGHT AND MORNING COASTAL DRIZZLE THE NEXT
FEW DAYS...NO PRECIPITATION IS FORECAST THROUGH NEXT WEEKEND.

&&

.AVIATION...AS OF 4:44 AM PDT MONDAY...FOR 12Z TAFS. WIDESPREAD
STRATUS BLANKETS THE REGION UNDER A 2600 FT MARINE LAYER THIS
MORNING. PARTIAL CLEARING IS EXPECTED LATER TODAY. HOWEVER KSFO
AND KOAK ALONG WITH MONTEREY BAY TERMINALS ARE NOT EXPECTED TO
CLEAR BUT RATHER WILL SEE CIGS LIFT TEMPORARILY TO AROUND
1500-2000 FT IN THE AFTERNOON. LIGHT TO LOCALLY MODERATE ONSHORE
FLOW WILL CONTINUE THROUGH TONIGHT.

VICINITY OF KSFO...MVFR CIGS WILL PREVAIL THROUGH THE MORNING.
CIGS WILL LIFT TO AROUND 1500 FT AFTER 20Z THIS AFTERNOON WITH
VERY LITTLE HOPE OF AREA TERMINALS SCATTERING OUT. LIGHT TO LOCALLY
MODERATE ONSHORE FLOW WILL PREVAIL.

KSFO BRIDGE APPROACH...IFR CIGS AROUND 1000 FEET EXPECTED THROUGH
EARLY THIS MORNING. CIGS WILL CLEAR FROM THE SOUTH LATER THIS MORNING
BUT AREA TERMINALS WILL REMAIN OVC AROUND 1500 FEET THROUGH THE
AFTERNOON.

MONTEREY BAY AREA TERMINALS...BORDERLINE IFR/MVFR CIGS WILL PERSIST
THROUGH THE MORNING. CIGS WILL LIFT AFTER 18Z-19Z MONDAY BUT AREA
TERMINALS ARE NOT EXPECTED TO CLEAR. LIGHT ONSHORE FLOW WILL
PREVAIL.

&&

.MARINE...AS OF 9:00 AM PDT MONDAY...NORTHWEST WINDS PERSIST OVER
THE CENTRAL CALIFORNIA COASTAL WATERS TODAY. VERY LOCALIZED AREAS
OF SQUARED SEAS POSSIBLE IN THE NORTHERN OUTER WATERS TODAY. WINDS
WEAKEN AND BACK TOWARDS THE WEST THROUGH MIDWEEK THEN VEER BACK
TOWARDS THE NORTHWEST AND INCREASE LATE IN THE WEEK. PREDOMINATELY
GENTLE SEAS THROUGH THE PERIOD.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM NOON

&&

$$

PUBLIC FORECAST: BELL/DYKEMA
AVIATION: CW
MARINE: DRP

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