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

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000
FXUS66 KMTR 271136
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
436 AM PDT MON APR 27 2015

.SYNOPSIS...STRENGTHENING HIGH PRESSURE WILL BRING WARM AND DRY
CONDITIONS TO THE ENTIRE AREA TODAY. A DRY COLD FRONT WILL APPROACH THE
COAST BY TUESDAY...RESULTING IN INCREASING ONSHORE FLOW AND A
MODEST COOLING TREND TUESDAY AND WEDNESDAY. DRY AND SEASONABLE
WEATHER IS THEN FORECAST FROM WEDNESDAY THROUGH THE UPCOMING WEEKEND.

&&

.DISCUSSION...AS OF 3:35 AM PDT MONDAY...SKIES ARE MOSTLY CLEAR
ACROSS THE ENTIRE REGION EARLY THIS MORNING AS AN UPPER RIDGE BUILDS
DIRECTLY OVER THE GOLDEN STATE. THE FORT ORD PROFILER SHOWS THAT
SUBSIDENCE WARMING UNDER THIS RIDGE HAS WARMED THE AIRMASS ALOFT
BY AS MUCH AS TEN DEGREES C OVER THE PAST 24 HOURS. ALSO...SURFACE
PRESSURE GRADIENTS DOWN THE COAST FROM ACV TO SFO HAVE BEEN
INCREASING WHILE GRADIENTS FROM THE COAST TO INLAND AREAS
DECREASE. ALL OF THESE DEVELOPMENTS POINT TO A WARMER DAY TODAY
ACROSS THE REGION...WITH AFTERNOON HIGHS EXPECTED TO BE 5 TO 10
DEGREES WARMER THAN YESTERDAY AND AS MUCH AS TEN DEGREES...OR
MORE...ABOVE NORMAL.

TODAY WILL BE THE WARMEST DAY OF THE WEEK FOR MOST LOCATIONS. THE
MODELS HAVE CONSISTENTLY FORECAST THE UPPER RIDGE TO MOVE OFF TO
OUR EAST BY TUESDAY...WHILE AN UPPER TROUGH OVER THE EASTERN
PACIFIC APPROACHES THE NORTHERN CA COAST. ALL OF THE MOISTURE WITH
THIS TROUGH...AND MOST OF THE COLD AIR AS WELL...WILL LIFT WELL TO
OUR NORTH PRIOR TO REACHING THE CA COAST. THE TROUGH
WILL...HOWEVER...PRODUCE AN INCREASE IN ONSHORE FLOW AND MODEST
COOLING TUESDAY AND WEDNESDAY. COOLING ON TUESDAY AND WEDNESDAY
WILL PRIMARILY BE NEAR THE COAST AND IN THE NORTHERN INTERIOR
SECTIONS OF OUR FORECAST AREA. SOUTHERN INLAND AREAS WILL SEE
LITTLE...IF ANY...COOLING.

THE GFS DEVELOPS UPPER LEVEL RIDGING OFF THE NORTHERN CA COAST BY
THURSDAY AND FRIDAY AS WELL AS LIGHT OFFSHORE FLOW...AND THUS
FORECASTS WARMER TEMPERATURES LATER IN THE WEEK. THE ECMWF...ON THE
OTHER HAND...FORECASTS A PIECE OF ENERGY FROM THE MIDWEEK SYSTEM
TO HANG BACK OFF THE CALIFORNIA COAST AS A WEAK UPPER LOW.
THUS...THE ECMWF HOLDS TEMPS NEAR PERSISTENCE FROM WEDNESDAY
THROUGH FRIDAY. THE CANADIAN HAS ASPECTS OF BOTH OF THESE
SOLUTIONS...BUT FAVORS THE GFS. FOR NOW HAVE GONE AHEAD AND
FORECAST MODEST WARMING LATE IN THE WEEK.

NO BIG CHANGES ARE FORECAST GOING INTO THE UPCOMING WEEKEND. DRY
WEATHER IS EXPECTED TO PERSIST ALONG WITH SLIGHTLY ABOVE NORMAL
TEMPERATURES.

&&

.AVIATION...AS OF 4:35 AM PDT MONDAY...A ROBUST 5 MB NORTHERLY
GRADIENT FROM ACV-SFO WILL MAINTAIN MAINLY CLEAR SKIES ACROSS
THE REGION THROUGH LATE TONIGHT. LIGHT WEST WINDS WILL PERSIST
THROUGH THIS MORNING THEN INCREASE THIS AFTERNOON. MODERATE WEST
WINDS ARE EXPECTED THROUGH THIS AFTERNOON AND EVENING. HIGH
CONFIDENCE.

VICINITY OF KSFO...VFR CONDITIONS EXPECTED THROUGH LATE TONIGHT.
LIGHT WINDS WILL INCREASE THIS AFTERNOON WITH SUSTAINED WINDS OUT
OF THE WEST BETWEEN 13 AND 18 KT. WINDS WILL EASE AFTER 05Z THIS
EVENING. HIGH CONFIDENCE.

SFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR CONDITIONS EXPECTED THROUGH LATE
TONIGHT. LIGHT WINDS WILL INCREASE THIS AFTERNOON WITH SUSTAINED
WEST WINDS AROUND 12 KT EXPECTED. WINDS WILL GRADUALLY EASE THIS
EVENING. HIGH CONFIDENCE.

&&

.MARINE...AS OF 2:48 AM PDT MONDAY...HIGH PRESSURE WILL MAINTAIN
MODERATE NORTHWESTERLY WINDS ACROSS THE COASTAL WATERS THROUGH
TONIGHT. WINDS ARE ANTICIPATED TO STRENGTHEN ON TUESDAY INTO
WEDNESDAY AS A COLD FRONT PUSHES TOWARDS THE CALIFORNIA COAST.
STRONG WINDS WILL PERSIST THROUGH THE END OF THE WEEK AS THE
FRONTAL SYSTEM MOVES ACROSS THE REGION.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...SF BAY NORTH OF THE BAY BRIDGE FROM 2 PM
             SCA...SF BAY SOUTH OF THE BAY BRIDGE FROM 2 PM
             SCA...MONTEREY BAY FROM 2 PM
             SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 2 PM
             SCA...PT ARENA TO PT REYES 10-60 NM FROM 6 PM
             SCA...PT REYES TO PIGEON PT 10-60 NM FROM 6 PM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 6 PM
             SCA...PT ARENA TO PT REYES 0-10 NM FROM 2 PM
             SCA...PT REYES TO PIGEON PT 0-10 NM FROM 2 PM

&&

$$

PUBLIC FORECAST: DYKEMA
AVIATION/MARINE: CW

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