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000
FXUS66 KMTR 061757
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
957 AM PST FRI DEC 6 2013

.DISCUSSION...AS OF 08:45 AM PST FRIDAY...TEMPERATURES ARE
RUNNING A FEW DEGREES WARMER THAN YESTERDAY MORNING AT MOST
LOCATIONS. WHILE SLIGHTLY WARMER...TEMPERATURES AGAIN WERE STILL
BELOW FREEZING AT MANY LOCATIONS. OVERNIGHT LOWS RANGED FROM
40 IN SAN FRANCISCO TO AS COLD AS 16 DEGREES IN POPE VALLEY IN
NORTHERN NAPA COUNTY. AT LEAST A FEW DAILY RECORDS LOOK TO HAVE
BEEN SET OR TIED SO A REPORT IS FORTHCOMING. THE FREEZE WARNING
WILL BE ALLOWED TO EXPIRE...THOUGH AFTER THE TONIGHT`S WEATHER
TEMPERATURES ARE EXPECTED TO PLUMMET ONCE AGAIN SO ANOTHER FREEZE
IS LIKELY.

A SHORTWAVE IS LOCATED IN THE PACIFIC NORTHWEST DROPPING SOUTH
ALONG THE COAST. THE 12Z NAM DEPICTS THE RAIN SLIGHTLY SLOWER THAN
PREVIOUS RUNS HOWEVER WAA COULD HAVE RAIN START AS EARLY AS LATE
AFTERNOON.

SHORT TERM GRIDS ARE ON TRACK AND NO UPDATES ARE NECESSARY AT THIS
TIME.

&&

.PREV DISCUSSION...AS OF 2:33 AM PST FRIDAY...CLEAR SKIES OVERHEAD ONCE
AGAIN ARE ALLOWING EARLY MORNING TEMPERATURES TO DROPPED INTO THE
20S AND 30S MOST AREAS. CURRENT READINGS ARE SIMILAR TO THOSE FROM
YESTERDAY AT THIS TIME...BUT SOME ARE AS MANY AS 5 DEGREES
WARMER...SOME LOCATIONS 5 DEGREES COOLER. IN GENERAL...DEW POINT
TEMPERATURES ARE WARMER...THUS ONE WOULD EXPECT SLIGHTLY WARMER
MINIMUM TEMPERATURES THIS MORNING COMPARED TO YESTERDAY. THE
FREEZE WARNING CURRENTLY IN EFFECT FOR ALL AREAS EXCEPT THE CITY
OF SAN FRANCISCO WILL EXPIRE AT 9 AM THIS MORNING.

NEXT ON THE HORIZON IS A COLD SHORTWAVE TROUGH FORECAST TO DROP
SOUTHWARD ALONG THE WEST COAST TODAY AND AFFECT OUR AREA LATER
THIS EVENING THROUGH SATURDAY MORNING. RAIN IS EXPECTED TO BEGIN
FROM SAN FRANCISCO NORTHWARD AS EARLY AS LATE THIS AFTERNOON...THEN
SPREAD QUICKLY SOUTH ACROSS THE REST OF THE AREA OVERNIGHT.
SHOWERS SHOULD END SATURDAY MORNING...AND QPF AMOUNTS ARE EXPECTED
TO RANGE FROM A QUARTER OF AN INCH TO THREE QUARTERS OF AN INCH.

SNOW LEVELS ARE EXPECTED TO DROP TO AS LOW AS 2000 FEET AFTER
FRONTAL PASSAGE ON FRIDAY NIGHT. MOST OF THE PRECIP WILL END
BEFORE THE COLDEST AIRMASS ARRIVES...BUT SNOW ACCUMULATIONS OF
BETWEEN 2 AND 4 INCHES ARE POSSIBLE ABOVE 2500 FEET AND UPWARDS
OF SIX INCHES COULD FALL ABOVE 3000 FEET IN THE SANTA LUCIAS.
WINTER WEATHER ADVISORIES ARE IN EFFECT FOR LATE FRIDAY NIGHT AND
SATURDAY MORNING AT ELEVATIONS ABOVE 2500 FEET IN THE SANTA CRUZ
MOUNTAINS AND EAST BAY HILLS/DIABLO RANGE AND FROM LATE FRIDAY
NIGHT THROUGH SATURDAY AFTERNOON ABOVE 2000 FEET IN THE MOUNTAINS
OF MONTEREY AND SAN BENITO COUNTIES.

MUCH COLDER AIR WILL FOLLOW THE COLD FRONT...THUS ANOTHER COUPLE
OF MORNINGS WITH POTENTIAL WIDESPREAD FREEZING OR BELOW-FREEZING
TEMPERATURES ARE EXPECTED BEGINNING SUNDAY MORNING. HIGH PRESSURE
WILL EVENTUALLY BUILD IN FOR WARMING TEMPERATURES BY TUESDAY OR
WEDNESDAY. ANOTHER SHOT OF PRECIPITATION CHANCES IS THEN FORECAST
FOR LATER NEXT WEEK.

&&

.AVIATION...AS OF 10:00 AM PST FRIDAY...APPROACHING STORM SYSTEM
WILL SPREAD RAIN ACROSS OUR AREA FOR LATER TODAY THROUGH TONIGHT.
RAIN WILL CHANGE TO SHOWERS FROM NORTH TO SOUTH OVERNIGHT. WINDS
FORECAST TO GO FROM SOUTHERLY TO NORTHWESTERLY BEHIND THE FRONT.
CIGS WILL DROP AS THE FRONT APPROACHES WITH MVFR CONDITIONS
POSSIBLE IN ALL SPOTS. MODERATE CONFIDENCE ON THE TIMING AND CIG
HEIGHTS.

VICINITY OF KSFO...VFR WITH LIGHT WINDS THROUGH THIS AFTERNOON.
LOWERING CIGS AND RAIN LIKELY BY AROUND 05Z SATURDAY WITH MVFR CIGS.
RAIN TO SHOWERS AROUND 12Z. HIGH TO MODERATE CONFIDENCE.

KSFO BRIDGE APPROACH...SIMILAR TO KSFO.

MONTEREY BAY AREA TERMINALS...VFR WITH CLEAR SKIES AND LIGHT WINDS
THROUGH EARLY EVENING. RAIN AND LOW CIGS EXPECTED AROUND 0800Z
WITH MVFR CIGS. SHOWERS BY 15Z. MODERATE CONFIDENCE.

&&

.CLIMATE...RECORD LOW TEMPERATURES FOR THE NEXT COUPLE OF DAYS.
NEW RECORDS SET ON DEC 5TH (*) AND TIED (T).

                     DEC 5TH      DEC 6TH    DEC 7TH
------------------------------------------------------
KENTFIELD.........  *26 (2013)   28 (1921)   28 (1927)
SAN RAFAEL........  *30 (2013)   32 (2009)   33 (1956)
NAPA..............  *25 (2013)   29 (1948)   28 (1972)
SAN FRANCISCO... .  T40 (2013)   40 (2009)   38 (1972)
DOWNTOWN OAKLAND..  *34 (2013)   38 (2005)   37 (1998)
RICHMOND..........  *33 (2013)   35 (1967)   35 (1956)
LIVERMORE.........   21 (1972)   26 (2009)   26 (1916)
MOUNTAIN VIEW.....  *32 (2013)   34 (2005)   34 (2009)
SAN JOSE..........  T29 (2013)   32 (1931)   29 (1896)
GILROY............  *26 (2013)   28 (1959)   25 (1960)
MONTEREY..........   31 (1942)   35 (1942)   31 (1942)
SANTA CRUZ........  *28 (2013)   29 (1912)   28 (1960)
SALINAS...........  *29 (2013)   29 (1960)   29 (1960)
KING CITY.........   20 (1941)   22 (1941)   22 (1956)

&&

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

&&

$$

PUBLIC FORECAST: AC/SIMS
AVIATION: BELL
CLIMATE: AC/SIMS

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