Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
FXUS66 KMTR 240549
Area Forecast Discussion
National Weather Service San Francisco Bay Area
1049 PM PDT TUE AUG 23 2016
.SYNOPSIS...Slightly warmer temperatures are forecast for
Wednesday as high pressure builds off of the California coast.
Modest cooling is then expected late in the week and into the
upcoming weekend as a weak upper level trough develops over
California. But for the most part, temperatures will remain near
seasonal averages through the forecast period and a persistent
marine layer will mean continued night and morning low clouds.
.DISCUSSION...As of 9:00 PM PDT Tuesday...Evening water vapor
satellite imagery shows an upper ridge building offshore along
130W and a longwave trough over the northern Rockies. In the
short-term the ridge will be the dominant weather feature for our
area, giving us slightly warmer temperatures going into
Wednesday. The upper trough over the northern Rockies is then
forecast to sag to the southwest and across California by late
Thursday. This will result in modest cooling for most areas late
in the work week and into the early part of the weekend. In
addition, a weak surface low is forecast to develop off the
northern and central California coast by late Thursday night or
Friday, which will result in southerly low level winds. These
southerly winds will likely bring about more significant cooling
by Friday in the North Bay Valleys and other locations that cool
with south winds, such as Santa Cruz and Big Sur.
The longer range models agree that upper level ridging will
develop over southern and central California during the first half
of next week, which will result a gradual warming trend.
Otherwise, no significant weather is anticipated. Persistent
onshore flow and a moderately deep marine layer will mean
continued night and morning low clouds clearing back to the coast
Winds in the vicinity of the Soberanes fire are forecast to be
out of the west and northwest through Thursday, which will direct
smoke from the fire to the east and southeast over the next few
days. The weak surface low that is forecast to develop off our
coast by late Thursday night into Friday will cause winds to turn
southerly. Thus, we can expect an increase in smoke to the north
of the Soberanes fire late in the week and possibly into the
.AVIATION...As of 10:48 PM PDT Tuesday...Onshore winds will usher
coastal stratus and fog inland tonight and Wednesday morning. Areas
IFR cigs/vsbys will gradually spread inland tonight and Wednesday
Vicinity of KSFO...MVFR cig forecast 10z-16z. Westerly winds becoming
gusty Wednesday afternoon and evening.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...IFR lowering to LIFR/VLIFR through Wednesday
morning. VFR forecast to return by late Wednesday morning.
.MARINE...as of 10:43 PM PDT Tuesday...Surface high pressure will
remain over the eastern Pacific. Winds will remain mostly light
northwest through the week. Gusty onshore winds are forecast north
of the Bay Bridge Wednesday afternoon and evening. A short period
northwest swell will continue to mix with a longer period southerly
swell through much of the forecast period.
.Tngt...SCA...SF Bay until 3 AM
PUBLIC FORECAST: Dykema
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