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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
442 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 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 4:45 AM PDT MONDAY...STRATUS CONFINED TO PATCHES
ALONG THE COAST. STRONG N-S PRESSURE GRADIENT WILL KEEP STRATUS
OUT OF THE SFO BAY AREA TODAY. CLOUDS ARE STARTING TO INCREASE
OVER THE WATERS AND WILL LIKELY IMPACT THE MRY BAY AREA THIS MORNING.

VICINITY OF KSFO...VFR. 

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR CURRENTLY AT MRY BUT INCREASING
STRATUS OVER THE WATER COULD BRING SOME BRIEF CIGS THROUGH 16Z.
SNS SITS UNDER A PATCH OF CIGS THAT EXTENDS INTO THE SALINAS VALLEY.
FOR SNS...IFR THROUGH 16-17Z.

&&

.MARINE...AS OF 3:00 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
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM UNTIL 9 AM

&&

$$

PUBLIC FORECAST: DYKEMA
AVIATION/MARINE: W PI

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