530 
FXUS66 KMTR 042144
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
244 PM PDT SAT JUL 4 2009

.DISCUSSION...AS OF 2:44 PM PDT SATURDAY...THE STRATUS TOOK A LITTLE
LONGER THAN EXPECTED TO SCATTER OUT OVER MONTEREY THIS AFTERNOON BUT
NOW SKIES ARE FINALLY LOOKING MOSTLY CLEAR ACROSS THE CWA. THE
LATEST VISIBLE SATELLITE IMAGE IS SHOWING STRATUS LINGER OFF OF
THE COAST AND IT IS EXPECTED TO RETURN THIS EVENING.

OF COURSE THE BIG CONCERN THIS EVENING IS WHETHER OR NOT THERE
WILL BE LOW CLOUDS TONIGHT FOR THE LOCAL FIRE WORKS DISPLAYS. LOW
CLOUDS ARE EXPECTED TO RETURN TO THE DISTRICT TONIGHT BUT THEY WILL
NOT AFFECT THE SAN FRANCISCO BAY AREA UNTIL AFTER MIDNIGHT.
UNFORTUNATELY...STRATUS IS EXPECTED TO RETURN TO THE MONTEREY BAY
SANTA CRUZ AREA AROUND 8:00 OR 9:00 PM PDT.

CURRENTLY THE WATER VAPOUR IMAGE IS SHOWING A TROUGH OF LOW
PRESSURE OFF OF THE PACIFIC NORTHWEST...CENTERED AT ABOUT 140 WEST
AND 43 NORTH. THE MODEL SOLUTIONS HAVE INITIALIZED WELL WITH THIS
FEATURE AND MOVE IT INTO NORTHERN CALIFORNIA AND SOUTHERN OREGON BY
SUNDAY EVENING. AS THE LOW SLIDES INLAND OVER THE PACIFIC NORTHWEST
QUASI ZONAL FLOW MOVES INTO THE CWA. 500MB HEIGHTS ARE PROGGED TO
FALL A BIT WITH THE 1200 UTC GFS SHOWING THE GREATEST COOLING
WEDNESDAY. THE GFS IS FORECASTING 850 MB TEMPERATURES AROUND 14
DEGREES CELSIUS BY WEDNESDAY AFTERNOON WHICH IS 4 DEGREES WARMER THAN
PREVIOUS RUNS.

&&

.AVIATION...AS OF 10:35 AM SATURDAY...WIDESPREAD STRATUS STILL OVER
MUCH OF THE AREA THIS MORNING. EXPECT LATER BURNOFF AT ALL TERMINALS
TODAY AS COMPARED TO YESTERDAY. THE MARINE LAYER IS DEEPER THAN
YESTERDAY AND IS APPROX AT 2K FEET WITH A STRONGER SFO-SAC GRADIENT
OF 2.3 MB.

VICINITY OF KSFO...KSFO IS IN A CLEAR PATCH WITH SCATTERED
CLOUDS AT ABOUT 1800 FEET. KOAK STILL HAS CEILINGS...WHICH
SHOULD CLEAR OFF WITHIN THE HOUR. AFTERNOON GUSTY NW WINDS WILL BE
POSS AT KSFO. STRATUS WILL MOVE IN AGAIN TONIGHT WITH SIMILAR
RESULTS.

KSFO BRIDGE APPROACH...CIGS AND BURN OFF TIME WILL BE LATER
THAN AT KSFO. EXPECT CLEARING BY 19Z.

MONTEREY BAY TERMINALS...STRATUS OVER MRY AND SNS THROUGH 19Z.
STRATUS WILL ONCE AGAIN MAKE AN EARLY RETURN TONIGHT.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
     .TDA...SCA...SF BAY STARTING AT 11 AM.

&&

$$

PUBLIC FORECAST: LARRY
AVIATION/MARINE: MM

NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO