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000
FXUS66 KMTR 141520
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
820 AM PDT FRI MAR 14 2014

.SYNOPSIS...DRY WEATHER CAN BE EXPECTED THROUGH THE MIDDLE OF NEXT
WEEK. LOOK FOR TEMPERATURES TO WARM OVER THE WEEKEND -- POSSIBLY
TO RECORD BREAKING LEVELS. SOME COOLING CAN BE EXPECTED NEXT WEEK
AS THE ONSHORE FLOW RETURNS.

&&

.DISCUSSION...AS OF 8:20 AM PDT FRIDAY...CLEARING FORECAST ACROSS
OUR AREA LATER THIS MORNING WILL LEAD TO MOSTLY SUNNY CONDITIONS
ALONG WITH TEMPERATURES CONTINUING TO RUN ABOVE NORMAL. BIGGER
STORY WILL BE OVER THE WEEKEND WITH THE RIDGE AXIS OVERHEAD PLUS
WARMEST 850 MB READINGS. THOSE WILL COMBINE WITH AN OFFSHORE FLOW
AT THE SURFACE TO PRODUCE VERY WARM READINGS FOR THIS TIME OF
YEAR. WOULD DEFINITELY EXPECT A FEW RECORDS TO FALL.

CURRENT FORECAST LOOKS ON TRACK -- WILL JUST DO AN UPDATE AS THE
CLOUDS BREAK THIS MORNING.

.PREVIOUS DISCUSSION...THE DRY TAIL END OF A WEATHER SYSTEM MOVING
IN TO THE PACIFIC NORTHWEST IS APPROACHING OUR DISTRICT...AND
RESULTING IN ENHANCEMENT OF THE MARINE LAYER AND A RETURN OF THE
MARINE STRATUS. LATEST GOES FOG PRODUCT IMAGERY...AND IN RATHER
SPECTACULAR DETAIL JUST REC`D SUOMI VIIRS NIGHTTIME HIGH RES
VISUAL IMAGE...SHOW COVERAGE ALONG MUCH OF THE COAST FROM PT REYES
SOUTH TO THE VICINITY OF THE MONTEREY PENINSULA...AND A BROAD
SWATH EXTENDING INLAND ACROSS SAN FRANCISCO AND THROUGH THE GOLDEN
GATE TO THE EAST BAY. LATEST BODEGA BAY AND FT ORD PROFILER DATA
INDICATE A MARINE LAYER DEPTH OF ABOUT 1300 FT. SOME THIN HIGH
CLOUDS ARE ALSO PASSING THROUGH ABOVE.

NAM MODEL AND IN-HOUSE LOCAL WRF MODEL BOUNDARY LAYER RH OUTPUT
BOTH INDICATE STRATUS SHOULD GENERALLY CLEAR BY MIDDAY...EXCEPT
ALONG THE SAN MATEO COAST AND IN THE VICINITY OF THE MONTEREY
PENINSULA. EXPECT AFTERNOON HIGHS TO BE AROUND 3 TO 5 DEGS COOLER
THAN ON THURSDAY...BUT STILL WELL ABOVE SEASONAL NORMS ESPECIALLY
INLAND.

THEN BEGINNING FRIDAY NIGHT AND CONTINUING THROUGH THE WEEKEND...MODELS
ARE IN EXCELLENT AGREEMENT THAT AN UPPER LEVEL RIDGE OF HIGH PRESSURE
WILL BUILD STRONGLY INLAND THROUGH NORTHERN AND CENTRAL CALIFORNIA...WITH
WARMING OF TEMPS ALOFT AND LOW-LEVEL FLOW TURNING OFFSHORE...ALBEIT
RATHER WEAKLY. THE NET RESULT FOR US WILL BE CLEAR SKIES AND
SIGNIFICANTLY WARMER DAYTIME TEMPS...ESP AWAY FROM THE COAST. THAT
SAID...MODEL TREND OVER THE PAST FEW DAYS HAS BEEN MILDLY IN THE
DIRECTION OF NOT QUITE AS MUCH WARMING ALOFT AND A BIT LESS BY WAY
OF OFFSHORE FLOW. ECMWF OUTPUT FROM A FEW DAYS AGO WAS PROJECTING
850 MB TEMPS OVER THE HEART OF THE BAY AREA WOULD REACH UP TO 16C
AT THE HEIGHT OF THE UPPER-LEVEL WARMING...BUT NOW CONFINED TO THE 14C
TO 14.5C RANGE. AND SIMILARLY WITH SURFACE TROUGHING SHIFTED JUST
A BIT MORE INLAND...AND SO A BIT LESS BY WAY OF OFFSHORE ORIENTED
FLOW. DOESN`T CHANGE THE BASIC PICTURE THAT DAYTIME MAX TEMPS WILL
REACH TO WELL-ABOVE SEASONAL NORMAL LEVELS...ESPECIALLY
INLAND...BUT CHANCES OF GETTING UP TO RECORD LEVELS HAS DIMINISHED
A BIT. ALSO NOT AS MUCH OF A WARM-UP NEAR THE COAST AS HAD BEEN
THINKING A COUPLE OF DAYS AGO.

IN THE SUNDAY EVENING TIME FRAME...MODELS PROJECT THE UPPER LEVEL
RIDGE WILL RAPIDLY WEAKEN AND SHIFT INLAND AS ANOTHER...AND A BIT
STRONGER...WEATHER SYSTEM RAPIDLY APPROACHES AND MOVES IN TO THE
PACIFIC NW. AGAIN NO PRECIP IS EXPECTED IN OUR AREA...BUT IT WILL
RESULT IN BOTH SIGNIFICANT COOLING OF THE AIR MASS ALOFT AND A
QUICK RETURN TO MODERATELY STRONG ONSHORE FLOW. COASTAL STRATUS
LOOKS TO RAPIDLY REDEVELOP SUNDAY EVENING...AND DAYTIME TEMPS ON
MONDAY WILL COOL SIGNIFICANTLY...THOUGH STILL GENERALLY REMAIN
SEVERAL DEGS ABOVE SEASONAL NORMS. FOR DOWNTOWN SAN FRANCISCO FOR
EXAMPLE...PRESENT FORECAST CALLS FOR A HIGH OF 72 ON SUNDAY COOLING
TO 67 ON MONDAY...BUT THAT`S STILL 5 DEGS ABOVE THE SEASONAL NORM
FOR THE DATE OF 62.

THEREAFTER NOT A GREAT DEAL OF CHANGE IS EXPECTED THROUGH ABOUT
MIDWEEK...BUT THEN RAIN CHANCES RETURN TO AT LEAST MORE NORTHERN
PORTIONS OF OUR DISTRICT AS LARGER-SCALE UPPER LEVEL TROUGHING
DEVELOPS ALONG THE WEST COAST AND RESULTS IN THE STORM TRACK
SHIFTING A BIT SOUTHWARD. WE`LL STILL BE ON THE SOUTHERN END OF
THE DISTURBANCES MOVING THROUGH...BUT CLOSE ENOUGH THAT WE COULD
SEE SOME PRECIP.

&&

.AVIATION...AS OF 4:56 AM PDT FRIDAY...FOR 12Z TAFS. 1500 FOOT
CLOUD DECK HAS SPREAD INTO SF BAY WITH LOWER CIGS ALONG THE COAST
AND AROUND MONTEREY BAY. EVIDENCE SUGGESTS CLOUD LAYER NOT TOO
THICK AND FAIRLY HIGH CONFIDENCE FOR CIGS BURNING OFF BY 1730Z. TAF
WAS COMPOSED CONSERVATIVE AND WOULDN`T BE SURPRISED TO SEE CLEARING
EARLIER...CLOSER TO 17Z. OTHERWISE WEST WINDS THIS AFTERNOON WITH
NO IMPACT TO OPERATIONS. THE PATTERN CHANGES TONIGHT SO NOT
CONVINCED WE`LL GET CIGS AGAIN TONIGHT INTO SATURDAY MORNING.

VICINITY OF KSFO...1400-1500 FOOT STRATUS DECK OVER AIRPORT SHOULD
MIX OUT PRETTY QUICKLY WITH ABOVE AVERAGE CONFIDENCE FOR VFR BY
1730Z. WEST WINDS THIS AFTERNOON WITH GUSTS TO 17 KT.

KSFO BRIDGE APPROACH...SO FAR CIGS AREN`T SHOWING UP AT THE BRIDGE
BUT WOULDN`T BE SURPRISED TO SEE MORE DEVELOPMENT CLOSE TO THE
BRIDGE THROUGH 16Z...OR FOR CLOUDS TO IMPAIR VISUALS BETWEEN THE
BRIDGE AND AIRPORT BUT CLEARING BY 16-17Z.

MONTEREY BAY AREA TERMINALS...MVFR CIGS FOR MONTEREY BAY TERMINALS
THROUGH 17Z...WITH SOME CONCERN THEY COULD LINGER LONGER FOR KMRY.
IF ANYTHING WITH NW WINDS CLOUDS WILL BE JUST WEST OF THE AIRPORT
FOR MUCH OF THE DAY.

&&

.CLIMATE...RECORD HIGH TEMPERATURES FOR MARCH 15-16
ALONG WITH THE MOST RECENT DATE IT OCCURRED.

SF BAY AREA
.LOCATION................ SAT 15      SUN 16
 KENTFIELD............... 85/2004     86/2004
 SAN RAFAEL.............. 83/1972     87/1972
 NAPA.................... 86/2004     88/2004
 SAN FRANCISCO........... 82/2004     85/1914
 SFO AIRPORT............. 81/2004     82/2004
 OAKLAND (DOWNTOWN)...... 85/2004     85/2004
 OAKLAND AIRPORT......... 83/2004     83/2004
 RICHMOND................ 85/2004     84/1972
 LIVERMORE............... 83/1972     88/1972
 MOFFETT FIELD........... 83/2004     84/2004
 SAN JOSE................ 84/2004     85/2004
 GILROY.................. 84/1994     85/2004

MONTEREY BAY AREA
.LOCATION................ SAT 15      SUN 16
 MONTEREY................ 81/2004     84/1978
 SANTA CRUZ.............. 83/1926     86/1914
 SALINAS................. 85/1972     87/2004
 SALINAS AIRPORT......... 83/1972     87/2004
 KING CITY............... 90/2007     91/2007

&&

.MARINE...AS OF 5 AM FRIDAY...SMALL CRAFT ADVISORIES OVER THE
OCEAN TODAY THROUGH EARLY SATURDAY FOR NW WINDS. NEXT CONCERN WILL
BE BUILDING NW SWELL LATER SUNDAY. WAVE MODELS SHOWING SEAS UP TO
13 FEET WITH LONG PERIODS AROUND 18 SECONDS. WITH SUNNY AND WARM
WEATHER FORECAST SUNDAY WILL HAVE TO CONSIDER A BEACH HAZARD
STATEMENT ON SUNDAY FOR POSSIBLE RIPS IN FUTURE FORECAST UPDATES.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDAY...SCA...PIGEON PT TO PT PINOS 0-10 NM FROM 1 PM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
             SCA...PT ARENA TO PT REYES 10-60 NM
             SCA...PT REYES TO PIGEON PT 10-60 NM
             SCA...PIGEON PT TO PT PINOS 10-60 NM FROM 1 PM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 10-60 NM FROM 1 PM
             SCA...PT ARENA TO PT REYES 0-10 NM
             SCA...PT REYES TO PIGEON PT 0-10 NM FROM 9 AM

&&

$$

PUBLIC FORECAST: BELL/BLIER
AVIATION: RWW
MARINE: RWW
CLIMATE: SA/MM

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