000
FXUS66 KMTR 051717
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
1017 AM PDT SUN JUL 5 2009

.DISCUSSION...AS OF 9:35 AM PDT SUNDAY...SUMMER TIME STRATUS IS IN
PLACE ACROSS THE CWA THIS MORNING. THE VISIBLE SATELLITE IMAGE IS
SHOWING SIMILAR STRATUS COVERAGE TO YESTERDAY ALONG THE COAST AND
PENETRATING INTO THE VALLEYS. FORT ORD PROFILER IS INDICATING THE
MARINE INVERSION TO NEARLY 2500 FEET THIS MORNING. STRATUS IS
EXPECTED TO SCATTER OUT BY LATE MORNING EARLY AFTERNOON. A TROUGH
OF LOW PRESSURE IS APPROACHING NORTHERN CALIFORNIA AND SHOULD PUSH
STRATUS BACK INTO THE CWA TONIGHT.

CURRENT MODEL SOLUTIONS ARE IN GOOD AGREEMENT WITH THE TIMING AND
MAGNITUDE OF THE APPROACHING TROUGH AND KEEP PRECIPITATION WELL TO
THE NORTH OF THE CWA. THE LARGEST IMPACT ASSOCIATED WITH THIS
TROUGH WILL BE BELOW NORMAL TEMPERATURE ACROSS MOST OF THE AREA FOR
THE FIRST HALF OF THE WEEK. THE OPERATIONAL GFS IS SHOWING
AFTERNOON 850MB TEMPERATURES DROPPING TO AROUND 16 DEGREES CELSIUS
MONDAY THROUGH WEDNESDAY. THIS WILL RESULT IN AFTERNOON
TEMPERATURES FALLING TO 4 TO 8 DEGREES FAHRENHEIT BELOW NORMAL. THE
MODELS ARE BUILDING A LARGE RIDGE OVER THE CENTRAL CONUS. THIS
RIDGE WILL RESULT IN WARMING FOR THE SECOND HALF OF THE WEEK AND
INTO THE WEEKEND.

ANOTHER...FEATURE ASSOCIATED WITH THE APPROACHING TROUGH IS A 100KT
JET MAX PASSING OVER NORTHERN CALIFORNIA TUESDAY INTO WEDNESDAY.
THIS WILL RESULT IN STRENGTHENING NORTHERLY WINDS ACROSS THE COASTAL
WATERS AND OVER THE NORTH BAY MOUNTAINS AND EAST BAY HILLS. AT THIS
POINT IT LOOKS LIKE MINIMUM RELATIVE HUMIDITIES...IN RELATION TO THE
WINDS...WILL STILL BE HIGH ENOUGH NOT TO RAISE ANY FIRE WEATHER
CONCERNS OVER THE MOUNTAINOUS AREAS.

&&

.AVIATION...AS OF 10:17 AM SUNDAY...MARINE LAYER AND ONSHORE FLOW
(APPROX 2MB FROM KSFO TO KSAC) EXISTS ONCE AGAIN THIS MORNING.
EXPECT SIMILAR OUTCOME TO YESTERDAY MORNING WITH CLEARING BACK TO THE
COAST BY 19Z.

VICINITY OF KSFO...SIMILAR BURN OFF TO YESTERDAY WHICH WOULD BE 18-
19Z FOR KSFO AND KOAK.  GUSTY WINDS AGAIN THIS AFTERNOON AT KSFO.
ONSHORE FLOW WILL USHER STRATUS BACK IN AGAIN TONIGHT 4-6Z.

KSFO BRIDGE APPROACH...SIMILAR TO YESTERDAY WITH CLEARING 18-19Z.

MONTEREY BAY TERMINALS...STRATUS CIGS 1100-1400 FEET THROUGH APPROX
20Z.  STRATUS WILL FILL IN AGAIN TONIGHT AFTER 00Z.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDA...SCA...SF BAY.

&&

$$

PUBLIC FORECAST: MHS
AVIATION/MARINE: SSA

NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO