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000
FXUS66 KMTR 160528
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA
1028 PM PDT SAT JUN 15 2013

.DISCUSSION...AS OF 9:00 PM PDT SATURDAY...COOL MARINE AIR SURGED
INLAND LAST NIGHT AND TODAY AS THE MARINE LAYER DEEPENED TO 2000
FEET AND ONSHORE FLOW GRADUALLY STRENGTHENED. HIGH TEMPERATURES
TODAY WERE AS MUCH AS 15 TO 20 DEGREES COOLER THAN
YESTERDAY...MAINLY IN AREAS NEAR THE COAST AND IN THE COASTAL
VALLEYS. CARMEL VALLEY`S HIGH OF 64 WAS 23 DEGREES COOLER THAN THE
BALMY 87 THERE YESTERDAY. IN GENERAL...HIGH TEMPERATURES WENT FROM
5 TO 10 DEGREES ABOVE NORMAL YESTERDAY TO SEVERAL DEGREES BELOW
NORMAL TODAY. MANY COASTAL AREAS REMAINED UNDER LOW OVERCAST ALL
DAY TODAY INCLUDING THE WESTERN HALF OF SAN FRANCISCO...COASTAL
SAN MATEO COUNTY...POINT REYES NATIONAL SEASHORE...AND THE SOUTHERN
PERIPHERY OF MONTEREY BAY FROM MOSS LANDING SOUTH THROUGH CARMEL.
AFTERNOON TEMPERATURES IN THESE CLOUDY AREAS DID NOT EVEN CLIMB
OUT OF THE 50S.

LITTLE CHANGE IS EXPECTED OVER THE NEXT COUPLE OF DAYS. MODERATE
ONSHORE FLOW AND A RELATIVELY DEEP MARINE LAYER WILL CONTINUE TO
PRODUCE WIDESPREAD NIGHT AND MORNING LOW CLOUDS AND FOG. INLAND
AREAS WILL SEE CLEARING BY MIDDAY BUT SOME COASTAL AREAS MAY SEE
TWO OR THREE CONSECUTIVE DAYS WITH NO SUN. TEMPERATURES PROBABLY
WON`T COOL ANY FURTHER NEAR THE COAST BUT SOME OF THE VALLEYS
FARTHEST INLAND MAY SEE SOME ADDITIONAL COOLING DURING THE NEXT
FEW DAYS. THE NAM GENERATES ABOUT TWO-TENTHS OF PRECIP IN COASTAL
SECTIONS OF SAN MATEO COUNTY FROM NOW THROUGH TUESDAY NIGHT AND
THIS IS CERTAINLY POSSIBLE GIVEN THAT THIS TYPE OF PATTERN OFTEN
PRODUCES COASTAL DRIZZLE IN COASTAL AREAS AND PARTICULARLY IN THAT
AREA. A FORECAST UPDATE EARLIER THIS EVENING INCLUDED THE
ADDITION OF PATCHY NIGHT AND MORNING COASTAL DRIZZLE FROM WESTERN
SAN FRANCISCO SOUTH ALONG THE COAST TO DAVENPORT. ALSO ADDED SOME
LOW POPS TO THOSE AREAS.

AN UPPER TROUGH IS CURRENTLY CENTERED OFFSHORE JUST INSIDE OF
140W. THIS TROUGH IS FORECAST TO MOVE SLOWLY EASTWARD OVER THE
NEXT FOUR DAYS...WITH THE TROUGH AXIS PROJECTED TO MOVE INLAND
ACROSS CALIFORNIA BY MIDWEEK. AS THE TROUGH DRAWS NEARER TO THE
COAST...THE AIRMASS ALOFT WILL BEGIN TO COOL MORE RAPIDLY. 850 MB
TEMPERATURES ARE FORECAST TO DROP TO ABOUT 9 DEGREES C BY TUESDAY.
THIS WILL RESULT IN INLAND TEMPERATURES COOLING FURTHER ON TUESDAY
AND WEDNESDAY...TO VALUES MORE THAN 10 DEGREES BELOW NORMAL IN
SOME LOCATIONS. THAT MUCH COOLING ALOFT OFTEN RESULTS IN THE
MARINE LAYER MIXING OUT WHICH IS DEFINITELY POSSIBLE BY TUESDAY
AFTERNOON. IN THAT CASE...COASTAL AREAS MAY SEE MORE SUN BY MIDWEEK.

THE UPPER TROUGH IS FORECAST TO MOVE WELL INLAND BY THURSDAY AND
HEIGHTS ARE FORECAST TO RISE STEADILY FROM THURSDAY INTO NEXT
WEEKEND. THEREFORE...LOOK FOR A GRADUAL WARMING TREND FROM
THURSDAY THROUGH SATURDAY...ESPECIALLY INLAND. CONTINUED ONSHORE
FLOW WILL MEAN ONLY SLIGHT WARMING AT THE COAST.

&&

.AVIATION...AS OF 10:30 PM PDT SATURDAY...STRATUS MOVED INTO SFO
AROUND 00Z THEN RETREATED. CURRENTLY STRATUS EXTENDS ACROSS THE
GOLDEN GATE INTO OAK/HWD BUT THE REST OF THE SFO BAY AREA IS
CLEAR. WITH A DEEP MARINE LAYER OF 2000 FEET AND STRONG ONSHORE
GRADIENTS...CIGS WILL SPREAD ACROSS THE SFO BAY AREA OVERNIGHT.

VICINITY OF KSFO...STRATUS HAS CLEARED OUT FOR NOW. MVFR CIGS TO
RETURN AFTER 08Z. LATE BURNOFF TIME OF 18Z EXPECTED.

KSFO BRIDGE APPROACH...SAME AS SFO.

MONTEREY BAY AREA TERMINALS...IFR CIGS BECOMING MVFR AFTER 16Z.
VFR AT SNS BY NOON BUT CHANCES ARE MVFR CIGS WILL REMAIN THROUGH
THE DAY AT MRY.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TNGT...SCA...PT ARENA TO PT REYES 0-10 NM
             SCA...PT REYES TO PIGEON PT 0-10 NM
             SCA...PT ARENA TO PIGEON PT 10-60 NM
             SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM FROM 1 AM
             SCA...SF BAY UNTIL 11 PM

&&

$$

PUBLIC FORECAST: DYKEMA
AVIATION/MARINE: W PI

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