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

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000
FXUS66 KMTR 252343
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
443 PM PDT SAT APR 25 2015

.SYNOPSIS...HIGH PRESSURE WILL PRODUCE WARM AND DRY CONDITIONS ON
SUNDAY AND MONDAY. A COOLING TREND WILL DEVELOP BY THE MIDDLE OF
NEXT WEEK AS A DRY UPPER TROUGH DEVELOPS OVER NORTHERN CALIFORNIA.

&&

.DISCUSSION...AS OF 03:00 PM PDT SATURDAY... THE COLD FRONT AND
ASSOCIATED PRECIPITATION BAND WHICH SWEPT THROUGH THE AREA
OVERNIGHT HAS NOW EXITED THE REGION TO THE SOUTH AND EAST. RAINFALL
TOTALS WERE IMPRESSIVE CONSIDERING THE SPEED AT WHICH THE FRONT
PUSHED THROUGH. THE PRECIPITABLE WATER PLUME ASSOCIATED WITH THIS
FRONTAL PASSAGE WAS AROUND 160% OF NORMAL. PRECIPITATION AMOUNTS
WERE HIGHEST OVER THE BIG SUR COASTLINE WHERE SEVERAL HIGH
ELEVATION LOCATIONS REPORTED OVER TWO INCHES OF RAINFALL AND PICO
BLANCO REPORTED 2.52 INCHES OF RAIN. RAINFALL TOTALS BETWEEN A
QUARTER AND THREE QUARTERS OF AN INCH WERE OBSERVED THROUGHOUT
MANY LOW LYING URBAN AREAS. SEE THE LATEST PNSMTR FOR ADDITIONAL
CITY BY CITY RAINFALL TOTAL OBSERVATIONS.

VISIBLE SATELLITE IMAGERY SHOWS RAPID CLEARING IN THE POST FRONTAL
ENVIRONMENT OVER THE FORECAST AREA... LEADING TO MOSTLY TO PARTLY
SUNNY CONDITIONS. TEMPERATURES ARE RUNNING A FEW DEGREES COOLER
THIS AFTERNOON VERSUS YESTERDAY AS A RESULT OF THE COOLER AIR MASS
IN THE WAKE OF THE FRONT. SFO-WMC HAS DWINDLED FROM 10MB ONSHORE
24 HOURS AGO TO 5 MB ONSHORE AS OF AN HOUR AGO. WINDS ARE EXPECTED
TO INCREASE ALONG THE COAST AS THE UPPER LOW RESPONSIBLE FOR THIS
MORNINGS RAIN ROTATES INTO THE GREAT BASIN... WHICH WILL CONTRAST
SHARPLY WITH THE HIGH PRESSURE SET TO PUSH INLAND SUNDAY. THIS
HIGH PRESSURE WILL RESULT IN A GENERAL WARMING AND DRYING TREND
WHICH WILL PEAK ON MONDAY. HIGH TEMPERATURES ARE EXPECTED TO BE IN
THE 60S ALONGSHORE TO 80S INLAND WHEN THE RIDGE APEX ALIGNS WITH
THE AREA MONDAY. THE HIGH PRESSURE RIDGE PROGRESSES DOWNSTREAM BY
MIDWEEK AND GIVE WAY TO A WEAK TROUGH TO THE NORTH. THIS WILL
PROMOTE MARGINAL COOLING BUT CONTINUE THE DRY TREND THROUGH THE
REMAINDER OF THE WORKWEEK. COASTAL STRATUS WILL ATTEMPT TO RETURN MONDAY
NIGHT/TUESDAY MORNING.

&&

.AVIATION...AS OF 4:37 PM PDT SATURDAY...AREA TERMINALS ARE REPORTING
VFR. GRADUALLY DRIER NW WIND FLOW SUPPORTS VFR FOR THE PERIOD EXCEPT
LOCAL MVFR CIGS ARE STILL POSSIBLE VERY LATE TONIGHT AS TEMPERATURES
COOL.

VICINITY OF KSFO...WESTERLY WIND GUSTS TO 30 KNOTS ARE QUITE LIKELY
THROUGH MOST OF THE EVENING...TIL 06Z. VFR SHOULD HOLD OVERNIGHT.

SFO BRIDGE APPROACH...EXPECTING LESS WIND THAN AT KSFO TERMINAL
OTHERWISE SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR SHOULD HOLD THROUGH THE EVENING.
GUSTY W-NW SURFACE WINDS ARE LIKELY TO RELAX AFTER SUNSET. IT`S A
LOWER CONFIDENCE FORECAST REGARDING LOW CLOUD REDEVELOPMENT LATE
TONIGHT...BUT FOR NOW DECIDED ON ADVERTISING VFR FOR THE OVERNIGHT
HOURS AND SATURDAY IN THE 00Z TAFS.

&&

.MARINE...AS OF 01:51 PM PDT SATURDAY...GUSTY NW WINDS WILL
CONTINUE TODAY THROUGH SUNDAY BEHIND LAST NIGHTS COLD FRONTAL
PASSAGE. MODERATE NORTHERLY WINDS ARE FORECAST TO PREVAIL THROUGH
MIDWEEK AS HIGH PRESSURE BUILDS OVER THE EASTERN PACIFIC AND THE
SURFACE PRESSURE GRADIENT STRENGTHENS. THE STRENGTHENING WINDS
WILL RESULT IN DETERIORATING SEA CONDITIONS.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 0-10 NM
             SCA...PT REYES TO PIGEON PT 0-10 NM
             SCA...PIGEON PT TO PT PINOS 0-10 NM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
             SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM
             SCA...PIGEON PT TO PT PINOS 10-60 NM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM
             SCA...MONTEREY BAY UNTIL 9 PM
             SCA...SF BAY NORTH OF THE BAY BRIDGE UNTIL 8 PM
             SCA...SF BAY SOUTH OF THE BAY BRIDGE UNTIL 8 PM

&&

$$

PUBLIC FORECAST: DRP
AVIATION: CANEPA
MARINE: RWW

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