000
FXUS66 KMTR 200549
AFDMTR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
950 PM PST WED NOV 19 2008
.DISCUSSION...AS OF 9:00 PM PST WEDNESDAY...IT WAS MUCH COOLER
TODAY ACROSS THE DISTRICT AS LOW PRESSURE ALOFT HAS DISPLACED THE
UPPER RIDGE WHICH IS NOW OVER THE ROCKY MOUNTAIN STATES. HIGHS TODAY
RANGED FROM THE 50S AND 60S NEAR THE COAST AND BAYS...TO THE 70S TO
LOWER 80S INLAND. THESE HIGHS WERE 5 TO 20 DEGREES COOLER THAN
YESTERDAY`S HIGHS.
A WEAK SHORTWAVE TROUGH CURRENTLY APPROACHING THE WEST COAST IS
SERVING TO DEEPEN THE MARINE LAYER...WHICH IS NOW ABOUT 1600 FEET
DEEP. EXPECT LOW CLOUDS AND FOG TO SPREAD INLAND ONCE AGAIN
TONIGHT...ALTHOUGH HIGH CLOUDS ASSOCIATED WITH THE SHORTWAVE TROUGH
ARE OBSCURING THE LOW CLOUDS FROM SATELLITE VIEW AT THIS TIME. THIS
SHORTWAVE MIGHT BRING SOME LIGHT RAIN TO THE NORTH BAY ON THURSDAY...
ALTHOUGH CHANCES ARE SMALL.
FROM PREVIOUS DISCUSSION...SKIES WILL BEGIN TO CLEAR TOMORROW NIGHT
AND SHOULD BE MOSTLY CLEAR FRIDAY THROUGH SATURDAY AS SURFACE HIGH
PRESSURE BUILDS INTO SOUTHERN OREGON AND NORTHERN CALIFORNIA
PRODUCING LIGHT OFFSHORE FLOW. THE EXTENDED FORECAST REMAINS TRICKY
AS THE ECMWF AND THE OPERATIONAL GFS HAVE NOT BEEN EXHIBITING MUCH
CONTINUITY IN THEIR SOLUTIONS. THE GFS IS NOT PORTRAYING AS DEEP OF
AN UPPER LOW AS THE ECMWF AND IS ALSO MUCH DRIER. THEREFORE...NO
SIGNIFICANT CHANGES HAVE BEEN MADE TO THE EXTENDED FORECAST WHICH IS
ADVERTISING SLIGHT CHANCE POPS IN THE CLIMATOLOGICALLY FAVORED
AREAS.
&&
.AVIATION...AS OF 9:50 PM PST WEDNESDAY...A FEW HIGH CLOUDS ARE
PASSING ACROSS NORTHERN AND CENTRAL CALIFORNIA AS A TROUGH MOVES
ACROSS NORTHERN CALIFORNIA. AREAS OF LOW CLOUDS HAVE MOVED INLAND
WITH PATCHES OF DENSE FOG DEVELOPING LATER TONIGHT. THE 1800 FOOT
DEEP MARINE LAYER WILL SPREAD INTO THE VALLEYS OVERNIGHT THEN BACK TO
THE COAST BETWEEN 19Z AND 22Z.
TERMINAL AERODROME FORECAST (TAFS) FORMAT CHANGE...
AS OF 0000Z (NOVEMBER 5 2008) THE NWS IN AGREEMENT WITH THE FAA HAS
CHANGED THE TAF FORMAT TO CONFORM TO INTERNATIONAL STANDARDS OUTLINED
IN ICAO ANNEX 3. THE CHANGE INCLUDES THE INITIATING OF 30-HOUR TAFS
FOR HIGH IMPACT U.S. AIRPORTS. TO ACCOMMODATE THE EXTENDED TAF
PERIOD...THE FORMAT OF ALL TAFS HAVE CHANGED. THE CHANGE INVOLVES
IDENTIFYING THE DATA ASSOCIATED WITH EACH TIME GROUP.
KSFO AND KOAK ARE NOW 30-HOUR TAFS.
FOR ADDITIONAL INFORMATION REGARDING THE CHANGE PLEASE VISIT THE
AVIATION WEATHER CENTERS WEBSITE:
HTTP://AVIATIONWEATHER.NOAA.GOV/NOTICE/TAF30.PHP
&&
.MTR WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC FORECAST: LARRY/ANDERSON
AVIATION/MARINE: EVANS
NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO
