FXUS66 KMTR 301720
AFDMTR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SAN FRANCISCO BAY AREA CA
920 AM PST MON NOV 30 2009

.DISCUSSION...AS OF 9:00 AM PST MONDAY...SKIES ARE CLEAR ACROSS THE
DISTRICT AT THIS TIME WITH TEMPS IN THE 40S AND 50S...WITH A FEW
30S IN THE INLAND VALLEYS. WINDS ARE LIGHT ACROSS THE DISTRICT.

SHOULD BE ANOTHER MILD/WARM DAY TODAY UNDER SUNNY SKIES AND LIGHT
WINDS AS A RIDGE CONTINUES ALONG THE COAST. RIDGING WILL CONTINUE
TO REMAIN ALONG THE COAST THROUGH THE REMAINDER OF THE WORK WEEK
CONTINUING THE MILD DAYS AND COOL NIGHTS.

A CHANGE IN THE PATTERN BEGINS OVER THE WEEKEND AS THE WESTERLIES
BEGIN TO UNDERCUT THE RIDGE ALONG THE COAST. THE MODELS CONTINUE TO
STRUGGLE WITH THE DETAILS OF THIS PATTERN...BUT IT APPEARS THAT
ENERGY FROM TYPHOON NIDA IN THE WESTERN PACIFIC WILL ENERGIZE THE
EAST ASIAN JET...WHICH WILL THEN UNDERCUT THE RIDGE. THE 12Z GFS IS
SLOWER THAN ITS PREVIOUS RUN...AND IS SLOWER THAN THE 00Z ECMWF.
WILL WAIT FOR THE 12Z ECMWF BEFORE MAKING ANY CHANGES/UPDATES TO
THE FORECAST. MORE ON THIS DEVELOPING PATTERN CHANGE IN THE
AFTERNOON DISCUSSION.

&&

.AVIATION...AS OF 9:20 AM PST MONDAY...CURRENTLY CLEAR SKIES WITH
SLIGHT OFFSHORE FLOW AROUND CENTRAL CA COAST DUE TO A RIDGE OF HIGH
PRESSURE BUILDING IN. SURFACE PRESSURE GRADIENTS WILL REMAIN WEAK
THROUGH THE NEXT 24-36 HOURS WITH ONLY LIGHT SEA-BREEZE WINDS
DURING THE AFTERNOON. EXPECT CONTINUED P6SM SKC THROUGH TONIGHT
WITH A SLIGHT CHANCE FOR PATCHY GROUND FOG NEAR KSTS AFTER 10Z.

VICINITY OF KSFO...CLEAR SKIES AND VFR VISIBILITIES THROUGH TONIGHT.
LIGHT AND VARIABLE WINDS WILL BECOME 8-12 KTS FROM THE NORTHWEST
AFTER 22Z.

KSFO BRIDGE APPROACH...CLEAR SKIES AND VFR VISIBILITIES THROUGH THE
PERIOD.

MRY BAY AREA TERMINALS...CLEAR SKIES AND VFR VISIBILITIES THROUGH
TONIGHT AND INTO TUESDAY MORNING. LIGHT WINDS BECOMING ONSHORE 7-10
KTS AFTER 21Z.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
    .TDA...NONE

$$

PUBLIC FORECAST: MHS
AVIATION/MARINE: BJT

NWS ON THE WEB AT WEATHER.GOV/SANFRANCISCO