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

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000
FXUS66 KMTR 300403
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
903 PM PDT FRI MAY 29 2015

.SYNOPSIS...NO BIG WEATHER CHANGES FORECAST FOR SATURDAY WITH
COASTAL STRATUS SPREADING INLAND OVERNIGHT. BY SUNDAY A SYSTEM
WILL APPROACH THE COAST WITH A SLIGHT CHANCE OF SHOWERS IN THE FAR
NORTH BAY. AS THE SYSTEM APPROACHES THE MARINE LAYER WILL DEEPEN
AND COOLER WEATHER WILL RETURN SUNDAY AFTERNOON WITH ONSHORE FLOW.
SEASONABLE TEMPERATURES AND CONTINUED DRY WEATHER FORECAST MONDAY
THROUGH THE MIDDLE OF NEXT WEEK.

&&

.DISCUSSION...AS OF 9:00 PM PDT FRIDAY...INLAND TEMPERATURES
FINISHED OFF THE DAY A FEW DEGREES WARMER TODAY WHILE AREAS ALONG
THE COAST AND BAYS WERE ALMOST IDENTICAL TO YESTERDAY NUMBERS.
OUR HOT SPOT AGAIN WAS PARKFIELD IN SOUTHERN MONTEREY COUNTY WITH
A HIGH OF 96 DEGREES. HOWEVER MOST LOCATIONS SAW TEMPERATURES IN
THE 60S NEAR THE COAST AND BAYS TO 70S AND 80S INLAND. THE MARINE
LAYER REMAINS AROUND 1500 FEET THIS EVENING WITH LITTLE CHANGE
ANTICIPATED THROUGH SATURDAY AFTERNOON.

A ROBUST 3.1 MB GRADIENT FROM SFO TO SAC GRADUALLY STRENGTHENED
THIS AFTERNOON AND EVENING TO 3.9 MB THIS LAST HOUR RESULTING IN A
MODERATELY STRONG SEABREEZE. SIMILAR CONDITIONS ARE EXPECTED
AGAIN SATURDAY AS THE RIDGE REMAINS IN PLACE OVER THE AREA.

ON SUNDAY THE WEATHER PATTERN IS ANTICIPATED TO CHANGE AS AN
LOW PRESSURE SYSTEM APPROACHES THE DISTRICT. THIS SYSTEM WILL
DEEPEN THE MARINE LAYER AS IT NEARS AS WELL AS WILL INTRODUCE
A SLIGHTLY COOLER AIRMASS TO THE REGION. PATCHY AREAS OF DRIZZLE
ALONG THE COAST CAN NOT BE RULED OUT ON SATURDAY AS THE MARINE
LAYER DEEPENS AND SQUEEZES OUT A FEW DROPS HERE AND THERE. A
SLIGHT CHANCE OF SHOWERS IS FORECAST SUNDAY EVENING INTO EARLY
MONDAY AS THE REMNANTS OF THE COLD FRONT MOVE THROUGH THE REGION.

FROM PREVIOUS DISCUSSION...
MEDIUM RANGE MODELS KEEP A ZONAL FLOW ALOFT ACROSS NORTHERN
CALIFORNIA THROUGH MUCH OF NEXT WEEK. THUS...ONSHORE FLOW WILL
KEEP SEASONABLY COOL TEMPERATURES ACROSS THE AREA. NIGHT AND
MORNING COASTAL STRATUS WILL BE THE NORM FOR THE FIRST WEEK OF
JUNE.

&&

.AVIATION...AS OF 5:00 PM PDT FRIDAY...STRATUS COVERS MUCH OF THE
COAST. UPPER LEVEL RIDGE MOVING OVER THE AREA IS STARTING TO
COMPRESS THE MARINE LAYER. ONSHORE FLOW IS STILL STRONG WITH 3.1
MB SFO-SAC SO STRATUS IS STILL EXPECTED IN EARLY WITH LOWER BASES.
THERE SHOULD BE ENOUGH SURFACE HEATING TO KEEP ANY CIGS IN THE SFO
BAY AREA ABOVE 1000 FEET THROUGH 04-05Z BUT AFTER THAT CIGS WILL
GRADUALLY DROP BELOW 1000 FEET.

VICINITY OF KSFO...MVFR CIGS AFT 01Z LOWERING TO IFR AFTER 05Z.
WEST WINDS TO 20 KT GUSTING TO 25 KT THROUGH 05Z.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...STRATUS COVERS THE SOUTHERN END OF
MRY BAY AND WILL FILL IN OVER MRY AFTER 01Z AND REACH SNS BY 04Z.

&&

.MARINE...AS OF 01:19 PM PDT FRIDAY...GENERALLY LIGHT TO LOCALLY
MODERATE NORTHWEST WINDS ARE EXPECTED TO PREVAIL TODAY...THE
STRONGEST WINDS ARE EXPECTED SOUTH OF POINT SUR AND ALONG THE
SONOMA COAST. WINDS ARE ANTICIPATED TO DECREASE ON SATURDAY AND
BECOME SOUTHERLY ON SUNDAY AS A LOW PRESSURE SYSTEM APPROACHES
FROM THE WEST. WINDS WILL STRENGTHEN OUT OF THE NORTH ONCE AGAIN
EARLY NEXT WEEK AS A THERMAL TROUGH BUILDS OVER CALIFORNIA.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...SF BAY SOUTH OF THE BAY BRIDGE UNTIL 11 PM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 11 PM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 11 PM

&&

$$

PUBLIC FORECAST: CW
AVIATION: W PI
MARINE: LARRY

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