000
FXUS66 KMTR 180018
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
518 PM PDT MON JUN 17 2013

.DISCUSSION...AS OF 2:01 PM PDT MONDAY...MOSTLY SUNNY WITH
SLIGHTLY BELOW NORMAL TEMPERATURES ACROSS THE DISTRICT THIS
AFTERNOON. SOME PATCHY STRATUS IS LINGERING NEAR PT REYES...THE
SAN MATEO COAST AND THE MONTEREY PENINSULA WITH CLEAR SKIES
ELSEWHERE. THE SFO TO SAC ONSHORE GRADIENT IS STRONG AT 4.2 MB
WITH GUSTY ONSHORE WINDS BEING REPORTED AT MOST SITES ALREADY THIS
AFTERNOON. GUSTS TO 30 MPH OUT IN THE DELTA WITH 32 MPH GUST LAST
HOUR AT KSFO. THE MARINE INVERSION LAYER IS POORLY DEFINED AT
AROUND 1500 FEET BUT WITH RELATIVELY COOL AIR ALOFT AND STRONG
BOUNDARY LAYER WINDS DONT EXPECT A WELL DEFINED LAYER TO FORM
OVERNIGHT. NONETHELESS THROUGH THE OVERNIGHT HOURS EXPECT STRATUS
TO FORM ALONG THE COAST AND INTO THE BAY.

NO BIG CHANGES FOR TUESDAY BUT OVERALL TREND SHOULD BE FOR SLIGHT
COOLING OF TEMPS AS UPPER TROUGH AXIS PASSES TO OUR NORTH WITH 850
MB TEMPS COOLING TO 10 CELSIUS OR LESS FROM THE BAY AREA NORTHWARD
AND LESS THEN 15 CELSIUS FOR SOUTHERN MONTEREY COUNTY. SO EVEN
WITH FULL SUNSHINE MOST INLAND AREAS WILL HOVER IN THE 70S WITH
80S CONFINED TO THE WARMEST INTERIOR SPOTS. TUESDAY LOOKS TO BE
THE COOLEST DAY OF THE WEEK WITH A SLIGHT REBOUND IN 850 MB TEMPS
BY WEDS AS THE TROUGH AXIS PUSHES EASTWARD.

A MORE NOTED WARMING TREND BACK TO SEASONABLE OR SLIGHTLY ABOVE
NORMAL TEMPERATURES IS FORECAST THURSDAY THROUGH SATURDAY WITH A
MORE NORTHERLY BOUNDARY LAYER WIND FLOW EXPECTED TO DEVELOP BEHIND
THE MIDWEEK TROUGH AS 850 MB TEMPS REBOUND TO ABOUT 20-21 CELSIUS
BY SATURDAY. THE FLOW MAY TURN ONSHORE WITH COASTAL COOLING BY
SUNDAY AFTERNOON AS A SYSTEM PASSES TO OUR NORTH.

ECMWF TRIES TO BUILD A WARM RIDGE OVER THE STATE FROM THE SOUTH
NEXT WEEK WHILE THE GFS AND GEM KEEP THE INFLUENCE OF THE UPPER
TROUGH OFF THE PACIFIC NW COAST IN CHARGE.

&&

.AVIATION...AS OF 5:10 AM PDT MONDAY...SKIES REMAIN MAINLY CLEAR
OVER AREA TERMINALS WITH THE EXCEPTION BEING KSFO THAT CURRENTLY
HAS A BROKEN CIGS OF 1000 FEET. TEMPORARY CLEARING POSSIBLE BUT
AM GOING PESSIMISTIC WITH A PREVAILING CIGS THROUGH THE EVENING.
GUSTY WINDS WILL PREVAIL ACROSS THE REGION THIS EVENING INTO LATE
TONIGHT AS THE ONSHORE GRADIENT FROM SFO-SAC HAS INCREASED TO OVER
5 MB. STRATUS IS EXPECTED TO RETURN OVER MOST AREA TERMINALS
TONIGHT WITH CLEARING ANTICIPATED BETWEEN 16Z-18Z TUESDAY MORNING.

VICINITY OF KSFO...CIGS HAVE ALREADY RETURNED OVER KSFO WITH ONLY
A SLIGHT POSSIBILITY OF THE STRATUS PULLING BACK TEMPORARILY THIS
EVENING. AS STATED ABOVE HAVE GONE PESSIMISTIC WITH THIS EVENINGS
FORECAST AND HAVE KEPT PREVAILING CIGS IN THROUGH THIS EVENING.
GUSTY WINDS WILL ALSO PREVAIL THIS EVENING AND THROUGH LATE
TONIGHT AS A STRONG ONSHORE GRADIENT CONTINUES.

KSFO BRIDGE APPROACH...1000 FOOT CIGS WILL SLOWLY FILL INTO THE
BAY THIS EVENING AFFECTING THE APPROACH BY 01Z-02Z. AN EARLY
CLEARING IS IN STORE AGAIN TUESDAY WITH THE BRIDGE SCATTERING OUT
AROUND 15Z. GUSTY WINDS WILL PERSIST THROUGH THIS EVENING THEN
GRADUALLY DIMINISH OVERNIGHT.

MONTEREY BAY AREA TERMINALS...VFR THROUGH THIS EVENING WITH CIGS
RETURNING AROUND 03Z OVER KMRY. CIGS WILL RETURN OVER KSNS AFTER
MIDNIGHT TONIGHT. CLEARING IS EXPECTED AROUND 16Z OVER KSNS AND
18Z OVER KMRY. GUSTY WINDS WILL CONTINUE THROUGH THIS EVENING THEN
DIMINISH AFTER SUNSET.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
             SCA...SF BAY UNTIL 11 PM
             SCA...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM

&&

$$

PUBLIC FORECAST: RWW
AVIATION/MARINE: CW

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