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

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FXUS66 KMTR 181142
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
342 AM PST THU DEC 18 2014

.SYNOPSIS...A FEW LIGHT SHOWERS WILL LINGER INTO THE MORNING...
OTHERWISE THE AREA WILL SEE A BRIEF LULL IN PRECIPITATION TODAY.
THE NEXT SYSTEM TO BRING RAIN BACK TO THE AREA WILL MOVE IN LATE
THIS EVENING THROUGH FRIDAY. AFTER SOME RESIDUAL SHOWERS ON
SATURDAY...A RIDGE OF HIGH PRESSURE WILL BUILD OVER THE WEST COAST
RESULTING IN A DRYING TREND THROUGH EARLY NEXT WEEK.

&&

.DISCUSSION...AS OF 3:30 AM PST THURSDAY...RESIDUAL LIGHT SHOWERS
ARE STILL OCCURRING WITH WEAK RADAR ECHOES MOVING FROM WEST TO
EAST ACROSS PORTIONS OF THE DISTRICT WITH THE STRONGER ECHOES NOW
WELL EAST OF OUR AREA. THESE ARE EXPECTED TO DIMINISH THIS
MORNING WITH A BREAK IN THE RAINY WEATHER EXPECTED THIS AFTERNOON
AS HIGH PRESSURE BRIEFLY BUILDS OVER THE AREA.

THIS BREAK WILL BE SHORT-LIVED...HOWEVER...AS THE NEXT SYSTEM IS DUE TO
ARRIVE THIS EVENING WITH LIGHT WARM FRONTAL RAINS SPREADING INTO
THE NORTH BAY AFTER SUNSET. THE MAIN FRONTAL BAND ISN`T EXPECTED
TO MOVE THROUGH UNTIL FRIDAY MORNING WITH BRIEF HEAVIER RAIN
POSSIBLE OVER THE NORTH BAY AS IT MOVES THROUGH...WITH LIGHTER RAIN
SOUTH. RESIDUAL SHOWERS ARE EXPECTED TO CONTINUE INTO SATURDAY
MORNING. RAINFALL AMOUNTS OF UP TO AN INCH IN THE NORTH BAY HILLS
ARE EXPECTED WITH A HALF INCH OR LESS EXPECTED ELSEWHERE.

HIGH PRESSURE IS THEN PROGGED TO BUILD ALONG THE COAST BEGINNING
ON SATURDAY. SOME OVERRUNNING MOISTURE COULD BRING A FEW SHOWERS TO
THE NORTH BAY LATE SATURDAY...OTHERWISE A DRYING TREND IS
INDICATED FOR THE DISTRICT THROUGH AT LEAST EARLY NEXT WEEK. THERE
ARE DIFFERENCES AMONGST THE MEDIUM RANGE MODEL SOLUTIONS WITH THE
GFS OFFERING A DRY SOLUTION THROUGH THE WEEK...WHILE BOTH THE ECMWF
AND GEM BRING IN AN INSIDE SLIDER TYPE TROUGH AFFECTING NORTHERN
CALIFORNIA LATE WEDNESDAY INTO THURSDAY WITH COOLER TEMPERATURES
AND POSSIBLE PRECIPITATION. IT SHOULD BE NOTED...HOWEVER...THAT BOTH
THE 6-10 DAY AND 8-14 DAY OUTLOOKS FROM THE CLIMATE PREDICTION
CENTER KEEP CALIFORNIA UNDER AN ABOVE NORMAL TEMPERATURE AND BELOW
NORMAL PRECIPITATION PATTERN THROUGH DECEMBER 23-27 AND 25-31
RESPECTIVELY.

&&

.AVIATION...AS OF 3:35 AM PST THURSDAY...A FEW LINGERING SHOWERS
ARE STILL IMPACTING TERMINALS...BUT THOSE SHOWERS WILL TAPER OFF
EARLY THIS MORNING. OTHERWISE...MVFR CIGS WILL BE THE STORY THIS
MORNING WITH SOUTHERLY FLOW. CIGS WILL LIFT THIS AFTERNOON AHEAD
OF THE NEXT SYSTEM. WARM FRONTAL RAIN WILL OVERSPREAD THE AREA
TONIGHT...FIRST N BAY THEN SPREADING SOUTH. WET RUNWAYS SEE LIKELY
FRIDAY MORNING FOR KSJC NORTHWARD.

VICINITY OF KSFO...MAINLY MVFR CIGS THROUGH THIS AFTERNOON. BRIEF
PERIOD OF VFR CIGS THIS AFTERNOON...BUT MVFR COND RETURN OVERNIGHT
WITH LOWERING CIGS AND -RA BY 08Z. WINDS SE AND LIGHT TO MODERATE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...MVFR CIGS WITH A LINGERING VCSH.
CIGS LIFT THIS AFTERNOON...BUT RE-DEVELOP TONIGHT AS THE NEXT
SYSTEM COMES IN.

&&

.MARINE...AS OF 3:35 AM PST THURSDAY...LARGE NORTHWEST SWELL TO
IMPACT THE COASTAL WATER STARTING FRIDAY AFTERNOON. LATEST MODEL
GUIDANCE PUTS A FORERUNNER WAVE OF NEAR 20 SEC AS EARLY AT 18Z
FRIDAY FOR NORTHERN WATERS. THE PERIOD WILL DIMINISH...BUT THE
SWELL WILL INCREASE 16 TO 19 FEET WITH A PERIOD OF 18 SECONDS.
THEREFORE...HAZARDOUS SEAS WILL BE POSSIBLE ALONG THE COASTAL
WATERS. THE LARGE SWELL WILL ALSO IMPACT THE BEACHES...ESPECIALLY
NORTH OF POINT REYES. A HIGH SURF ADVISORY HAS BEEN ISSUED FOR SURF
15-18 FEET WITH A FEW BREAKERS OVER 20 FEET. LARGEST SURF NORTH OF
PT REYES.


&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...NONE.

&&

$$

PUBLIC FORECAST: SIMS
AVIATION/MARINE: MM

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