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

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000
FXUS66 KMTR 011724
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1024 AM PDT MON SEP 1 2014

.SYNOPSIS...HIGH PRESSURE BUILDING ALONG THE CALIFORNIA COAST
WILL RESULT IN MOSTLY SUNNY SKIES AND WARM AFTERNOON TEMPERATURES
ON LABOR DAY. TEMPERATURES WILL THEN COOL ON TUESDAY AND WEDNESDAY
AS AN UPPER TROUGH DEVELOPS NEAR THE WEST COAST. DRY CONDITIONS
WILL PREVAIL EXCEPT FOR POSSIBLE PATCHY NIGHT AND MORNING DRIZZLE
IN COASTAL AREAS AROUND MIDWEEK.

&&

.DISCUSSION...AS OF 09:21 AM PDT MONDAY...THE FORT ORD PROFILER
THIS MORNING SHOWS A SLIGHTLY DEEPER MARINE LAYER IN PLACE ACROSS
THE REGION. AS A RESULT... COASTAL CLOUDS FORMED OVERNIGHT OFF
THE SAN MATEO COAST SOUTHWARD AND SPREAD INLAND DOWN THE SALINAS
VALLEY. AROUND THE SAN FRANCISCO BAY...GENERALLY CLEAR SKIES
PREVAIL THIS MORNING. SHOULD SEE BURN-OFF OF INLAND CLOUDS BY LATE
MORNING WITH PLENTY OF SUNSHINE ACROSS THE REGION. INLAND
TEMPERATURES THIS AFTERNOON WILL BE A FEW TO SEVERAL DEGREES ABOVE
SEASONAL AVERAGES IN RESPONSE TO A MID/UPPER LEVEL HIGH PRESSURE
OVERHEAD. MADE MINOR CHANGES TO THE FORECAST TO REFLECT TRENDS IN
THE CLOUD COVER PER VISIBLE SATELLITE IMAGERY. OTHERWISE...THE
FORECAST LOOKS ON TRACK FOR THE REMAINDER OF THE AFTERNOON.

&&

.PREV DISCUSSION...AS OF 3:35 AM PDT MONDAY...UPPER LEVEL RIDGING
OVER SOUTHERN AND CENTRAL CALIFORNIA WILL PRODUCE WARM WEATHER
CONDITIONS ACROSS OUR REGION ON THIS LABOR DAY. THE FORT ORD
PROFILER SHOWS THAT THE MARINE LAYER HAS BEEN COMPRESSED TO A
DEPTH OF LESS THAN 500 FEET EARLY THIS MORNING AND SATELLITE
REVEALS ONLY PATCHY LOW CLOUDS...MAINLY NEAR MONTEREY BAY. ONSHORE
PRESSURE GRADIENTS HAVE DECREASED SINCE YESTERDAY MORNING AND SOME
LOCATIONS IN THE HILLS ARE EXPERIENCING LIGHT EASTERLY WINDS. ALL
OF THESE FACTORS POINT TO A WARMER DAY TODAY WITH AFTERNOON HIGHS
LIKELY TO BE SEVERAL DEGREES ABOVE NORMAL IN MOST AREAS.

WATER VAPOR SATELLITE IMAGERY CURRENTLY SHOWS AN UPPER LEVEL
TROUGH MOVING THROUGH THE GULF OF ALASKA. THIS TROUGH IS FORECAST
TO DROP TO THE SE ALONG THE BC COAST TONIGHT AND THEN SLIDE
THROUGH THE PAC NW TUESDAY AND TUESDAY NIGHT. THIS WILL TRIGGER
AN INCREASE IN ONSHORE FLOW ACROSS OUR REGION ON TUESDAY AS WELL
AS AN INCREASE IN THE DEPTH OF THE MARINE LAYER. THE RESULT WILL
BE COOLER CONDITIONS ON TUESDAY...AS MUCH AS TEN DEGREES COOLER
FOR INLAND AREAS COMPARED TO TODAY.

THE BULK OF THE ENERGY WITH THE INCOMING UPPER TROUGH WILL MOVE
RAPIDLY EAST ALONG THE U.S.-CANADIAN BORDER ON TUESDAY NIGHT AND
WEDNESDAY. HOWEVER...THE TAIL END OF THIS TROUGH IS FORECAST TO
LINK UP WITH A WEAK MID/UPPER LEVEL CYCLONIC CIRCULATION CENTER
CURRENTLY WELL OFFSHORE ALONG 140W (REMNANTS OF MARIE) AND FORM A
WEAK UPPER LEVEL TROUGH NEAR THE NORTHERN CA COAST BY MIDWEEK.
THIS TROUGH WILL THEN PERSIST THROUGH THE REMAINDER OF THE WEEK
AND PERHAPS INTO NEXT WEEKEND AS WELL. THERE DOES NOT APPEAR TO
BE SUFFICIENT MOISTURE WITH THE MARIE REMNANTS TO PRODUCE ANY
REAL CHANCE OF PRECIPITATION. HOWEVER...BY TUESDAY NIGHT THERE
MAY BE SUFFICIENT LOW LEVEL MOISTURE AND LIFT WITHIN A MUCH
DEEPER MARINE LAYER TO PRODUCE PATCHY DRIZZLE ALONG OUR
COAST...PARTICULARLY ALONG SOUTHWEST-FACING COASTAL TERRAIN AS
LOW LEVEL FLOW WILL BY THEN TAKE ON A SOUTHERLY COMPONENT. HAVE
ADDED VERY LOW POPS AND PATCHY DRIZZLE TO THE FORECAST FOR
COASTAL AREAS FOR LATE TUESDAY NIGHT/WEDNESDAY MORNING AND AGAIN
WEDNESDAY NIGHT/THURSDAY MORNING.

ALTHOUGH WEAK UPPER LEVEL TROUGHING IS EXPECTED TO CONTINUE
ACROSS NORTHERN CALIFORNIA THROUGH NEXT WEEKEND...THE UPPER
TROUGH AXIS IS FORECAST TO SHIFT INLAND WHICH SHOULD ALLOW FOR
MODEST WARMING BY FRIDAY OR SATURDAY.

&&

.AVIATION...AS OF 10:20 AM PDT MONDAY...PATCHY STRATUS CONFINED TO
AREAS ALONG THE COAST THIS MORNING AND ALL TERMINALS CLEAR.
NORTHERLY GRADIENT IS SET TO WEAKEN HOWEVER WITH SOMEWHAT SHALLOW
MARINE LAYER STRATUS LIKELY TO BE PATCHY AGAIN TONIGHT.

VICINITY OF KSFO...VFR TODAY. WEST WINDS TO AROUND 15 KT. STRATUS
TONIGHT EXPECTED TO BE PATCHY AND MOSTLY CONFINED TO COAST AND
EAST BAY.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR TODAY. LIGHT TO MODERATE SEA
BREEZE. STRATUS TO RETURN LATE EVENING.

&&

.MARINE...AS OF 09:21 AM PDT MONDAY...HIGH PRESSURE EXTENDS FROM
THE EASTERN PACIFIC INTO THE PACIFIC NORTHWEST. MODERATE NORTHWEST
WINDS CONTINUE ALONG THE CALIFORNIA COAST. THE WINDS WILL DECREASE
OVER THE SOUTHERN WATERS TUESDAY THROUGH THURSDAY AS A THERMAL
TROUGH DEVELOPS ALONG THE COAST.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM
             SCA...PT ARENA TO PT REYES 0-10 NM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM
             SCA...PIGEON PT TO PT PINOS 10-60 NM

&&

$$

PUBLIC FORECAST: RGASS
AVIATION/MARINE: AC

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