FXUS66 KMTR 101644
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
945 AM PDT SAT MAY 10 2008

.DISCUSSION...AS OF 8:54 AM SATURDAY...A SUMMER-LIKE PATTERN IS
UNDERWAY WITH LOW CLOUDS AND FOG ALONG THE COAST FROM SAN FRANCISCO
SOUTHWARD...AND EXTENDING WELL INTO THE SALINAS VALLEY. A MODERATE
ONSHORE FLOW EXISTS WITH A SURFACE PRESSURE GRADIENT OF 2.0 MB FROM
SFO TO SAC...AND ONLY 2.3 MB FROM ARCATA TO SAN FRANCISCO. 24-HOUR
TEMPERATURE TRENDS ARE SLIGHTLY WARMER THAN YESTERDAY AT THIS TIME...
AND GIVEN THE OVERALL PATTERN OF WEAK RIDGING ALOFT OVER CALIFORNIA
TODAY...EXPECT SLIGHTLY WARMER MAX TEMPS THIS AFTERNOON DISTRICT-
WIDE. A WEAK TROUGH PROGGED TO SWING ACROSS THE WEST COAST ON SUNDAY
IS EXPECTED TO INCREASE THE ONSHORE FLOW RESULTING IN GUSTY WINDS
ALONG THE COAST...AN INCREASE IN THE MARINE LAYER...AND COOLER
TEMPERATURES ONCE AGAIN MOST AREAS.

MONDAY IS EXPECTED TO BE SIMILAR TO SUNDAY TEMPERATURE-WISE...BUT BY
TUESDAY MUCH WARMER CONDITIONS WILL MOVE IN AS HIGH PRESSURE ALOFT
STARTS TO BUILD OVER THE AREA AND THE SURFACE FLOW BECOMES OFFSHORE.
MAX TEMPS ARE FORECAST TO CLIMB BY 10-15 DEGREES BY MIDWEEK WITH
COASTAL AREAS WARMING INTO THE 70S AND INLAND TEMPERATURES PUSHING
TRIPLE DIGITS.

THERE ARE SLIGHT DIFFERENCES AMONGST THE MEDIUM RANGE MODEL SOLUTIONS
BY NEXT WEEKEND WITH THE ECMWF FEATURING A MUCH STRONGER RIDGE
HOLDING OVER THE WEST COAST WHILE THE GFS HAS A WEAKER ONE. EITHER
WAY...DRY CONDITIONS TO PERSIST AS SUMMERTIME APPROACHES.

&&

.AVIATION...AS OF 9:40 AM SATURDAY...THIN SLIVER OF STRATUS
CONTINUES SOUTH OF THE GOLDEN GATE ALONG THE COAST...AS WELL AROUND
THE MONTEREY PENINSULA. APPEARS SOME EDDY CIRCULATION IN THE
MONTEREY BAY IS HELPING TO PUSH LOW CLOUDS BACK TOWARD THE COAST...
BRINGING SOME MID-MORNING CLEARING TO SNS/MRY. OTHERWISE...OTHER
TERMINALS EXPECTED TO REMAIN VFR THROUGH THE DAY WITH SLIGHTLY
COMPRESSED MARINE LAYER UNDER 2KFT. ONSHORE FLOW HOWEVER WILL PICK
UP AGAIN AFTER 20Z WITH GUSTS OVER 20KT LIKELY AT SFO. INCOMING WEAK
TROF EXPECTED TO DEEPEN MARINE PUSH TONIGHT...WITH SATELLITE
IMAGERY ALREADY INDICATING RENEWED STRATUS GENERATION ABOUT 40NM
OFFSHORE. THEREFORE EXPECT LOCAL STRATUS TO REDEVELOP MONTEREY BAY
BY 02Z WITH LATER PUSH IN THE BAY AREA TERMINALS...PROBABLY
ADVECTING INTO SFO/OAK TOWARDS 10Z-12Z. LATER CLEARING EXPECTED
TOMORROW AS DEEPER LAYER HARDER TO SCOUR OUT AND LACK OF COOLING
ALOFT WILL INHIBIT MIXING SO LOOKING AT 18Z OR SO AT SFO.

$$

.MTR WATCHES/WARNINGS/ADVISORIES...
       .TDA...SCA...PT ARENA TO PT PIEDRAS BLANCAS 0-60 NM.
             .SCA...SF BAY.

$$

PUBLIC FORECAST: ANDERSON
AVIATION/MARINE: SOROKA

NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO