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

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000
FXUS66 KMTR 281205
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
405 AM PST SAT FEB 28 2015

.SYNOPSIS...A STORM SYSTEM WILL BRING SHOWERS AND COOLER
TEMPERATURES TO THE AREA THROUGH SATURDAY NIGHT. ANOTHER WEAK
SYSTEM WILL BRING ADDITIONAL SHOWER CHANCES TO THE AREA ON MONDAY.

&&

.DISCUSSION...AS OF 3:20 AM PST SATURDAY...AN UPPER TROUGH
CONTINUES TO SAG SOUTH OVER NORTHERN CALIFORNIA. TWO UPPER LEVEL
LOW CENTERS ARE ROTATING WITHIN THIS TROUGH. SHOWERS ASSOCIATED
WITH THE SOUTHERN-MOST LOW CENTER CONTINUE TO MOVE SOUTHEASTWARD
OVER THE COASTAL WATERS AND OVER SAN MATEO...SANTA CRUZ AND
MONTEREY COUNTIES. MEASURABLE RAINFALL SO FAR HAS BEEN LIMITED TO
MONTEREY COUNTY...MOUNT TORO HAS PICKED UP THE MOST THUS FAR WITH
0.35 OVER THE LAST 12 HOURS. EXPECT SHOWER ACTIVITY TO INCREASE
TODAY...BUT CONTINUE TO BE MOST NUMEROUS ACROSS THE SOUTHERN HALF
OF THE DISTRICT. THUNDERSTORMS WILL BE POSSIBLE TODAY THROUGH THIS
EVENING IN THIS UNSTABLE AIRMASS. RAINFALL AMOUNTS ARE EXPECTED TO
BE LESS THAN ONE-TENTH OF AN INCH FOR THE SFO BAY AREA WITH ONE-
QUARTER TO ONE-HALF INCH TO THE SOUTH.

SHOWER CHANCES WILL DIMINISH OVER THE SFO BAY AREA DURING THE
NIGHT SATURDAY BUT CHANCES WILL CONTINUE SOUTH OF THE SFO BAY
AREA ALONG WITH POSSIBLE THUNDERSTORMS AND SMALL HAIL. SNOW
LEVELS WILL LOWER TO AROUND 4000 FEET SO THE HIGHER MOUNTAINS COULD
SEE A DUSTING OF SNOW. SHOWER ACTIVITY IS EXPECTED TO LARGELY END BY
SUNDAY EXCEPT FOR RESIDUAL SHOWERS POSSIBLE OVER THE SANTA LUCIA
AND SAN BENITO MOUNTAINS.

A SECOND UPPER LEVEL SYSTEM WILL MOVE INTO THE AREA MONDAY
BRINGING ADDITIONAL RAIN CHANCES TO THE AREA. LATEST COMPUTER
MODELS HAVE THIS SYSTEM TRACKING QUICKLY SOUTHWARD ALONG THE COAST
WITH PRECIP EXITING THE DISTRICT BY TUESDAY MORNING. TEMPERATURES
WILL REMAIN COOL THROUGH EARLY NEXT WEEK. HIGH PRESSURE IS
PROGGED TO REBUILD OVER THE WEST COAST FROM MIDWEEK ON. THIS WILL
USHER IN A WARMING AND DRYING TREND. WILL BUILD BACK TO OUR REGION
WEDNESDAY AS THE STORM TRACK MOVE

&&

.AVIATION...AS OF 4:05 AM PST SATURDAY...A STORM SYSTEM IS PASSING
OVER THE FORECAST AREA THIS MORNING...PROMOTING SHOWERS IN AND
AROUND THE MONTEREY BAY AREA. COOL AIR ALOFT ASSOCIATED WITH THIS
STORM SYSTEM WILL ALLOW FOR SHOWERS TO POP UP OVER THE SAN
FRANCISCO BAY AREA AND THE MONTEREY BAY AREA LATER THIS MORNING
INTO THE AFTERNOON AND EARLY EVENING HOURS. THE SHOWERS WILL BE
PERIODIC IN NATURE AND WILL RESULT IN OCCASIONAL WET RUNWAYS.

VICINITY OF KSFO...SHOWERS WILL BE IN THE VICINITY OF THE
TERMINALS THIS MORNING WITH SHOWERS IMPACTING THE TERMINALS
PERIODICALLY THROUGHOUT THE DAY TODAY. CIGS SHOULD REMAIN VFR WITH
OCCASIONAL MVFR DURING PERIODS OF HEAVIER SHOWERS. WESTERLY WINDS
ARE EXPECTED TO PREVAIL TODAY...REACHING 10 TO 15 KT.

CONFIDENCE IS MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...SHOWERS WILL PERIODICALLY IMPACT THE
TERMINALS THROUGHOUT THE DAY TODAY. CIGS SHOULD REMAIN VFR WITH
OCCASIONAL MVFR DURING PERIODS OF HEAVIER SHOWERS. WESTERLY WINDS
ARE EXPECTED TO PREVAIL TODAY...REACHING 10 TO 15 KT.

CONFIDENCE IS MODERATE.

&&

.MARINE...AS OF 2:35 AM PST SATURDAY...A STORM SYSTEM WILL
CONTINUE TO MOVE OVER THE COASTAL WATERS TODAY PROMOTING A
POSSIBILITY OF SHOWERS AND ISOLATED THUNDERSTORMS. NORTHERLY WINDS
WILL DECREASE THROUGHOUT THE DAY AS THE CENTER OF THE STORM SYSTEM
PASSES BY. THE DECREASING WINDS WILL RESULT IN IMPROVING SEA
CONDITIONS OVERNIGHT INTO SUNDAY. NORTHERLY WINDS WILL INCREASE
ONCE AGAIN MONDAY AS THE SURFACE PRESSURE GRADIENT INCREASES.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM UNTIL 3 PM
             SCA...PIGEON PT TO PT PINOS 10-60 NM UNTIL 3 PM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM UNTIL 3 PM

&&

$$

PUBLIC FORECAST: SIMS
AVIATION/MARINE: LARRY

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