FXUS66 KMTR 100710
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1210 AM PDT Mon Aug 10 2026
...New SHORT TERM, LONG TERM, FIRE WEATHER...
.KEY MESSAGES...
Updated at 1205 AM PDT Mon Aug 10 2026
- Elevated fire weather conditions in the higher terrain Monday
- Minor coastal flooding for bayshore locations along the San Francisco
Bay, San Pablo Bay, and Monterey Bay through Thursday morning
- Cooling trend through Thursday will bring well below normal
temperatures
- Up to a 10% chance for elevated rain showers/thunderstorms
Wednesday and Thursday
&&
.SHORT TERM...
Issued at 1205 AM PDT Mon Aug 10 2026
(Today and tonight)
Upper-level shortwave troughing developing off the West Coast Monday
will kickoff the cooling trend. The 1,000 foot marine layer will
likely remain steady, at least initially, with drizzle possible in
the mornings. The aforementioned troughing will result in an
increase of onshore flow with gusts up to 30 mph in the
afternoon/evening through gaps/passes and across ridgelines. This
will lead to elevated fire weather conditions across the higher
terrain coming off the heels of very hot and dry conditions. Minor
coastal flooding is expected during the highest high tide
(evening/overnight) for bayshore locations along the San Francisco
Bay, San Pablo Bay, and Monterey Bay through Thursday morning.
&&
.LONG TERM...
Issued at 1205 AM PDT Mon Aug 10 2026
(Tuesday through Sunday)
A reinforcing trough Wednesday will bring widespread below normal
temperatures and deepen the marine layer. Global ensemble clusters
are in agreement that heights and subsequently temperatures will
fall through Thursday as it digs. An increase in monsoonal/sub-
tropical moisture is bringing a low (up to 10%) chance for elevated
rain showers/thunderstorms with ingredients seemingly only marginal
as of now. Best chances look to be Wednesday through Thursday and
would likely favor the far southern and eastern parts of the area as
the conveyor belt of moisture stays between troughing to the west
and ridging to the east. While confidence is low, this would be a
high-impact scenario with gusty outflow winds and the potential for
new fire starts. It's going to be a fair fight going into the
weekend between a reinforcing trough off the West Coast and a
rebuilding ridge across a majority of the rest of CONUS. The
official forecast has a slight warming trend into the weekend, most
noticeable across the Interior Central Coast.
&&
.AVIATION...
(06Z TAFS)
Issued at 929 PM PDT Sun Aug 9 2026
Currently VFR except for KHAF and the Monterey Bay terminals.
Expect primarily onshore flow, however offshore eddy's are
complicating the inland push of the stratus, producing short
windows of local offshore flow. Should see MVFR/IFR ceilings
materialize after midnight and persist through at least late
morning.
Vicinity of SFO...Offshore eddys should continue to complicate the
exact timing of MVFR/IFR ceilings until after midnight. Given the
uncertainty of how much the eddys will impact how well organized
the marine layer is, maintained late morning clearing instead of
early afternoon indicated by some guidance.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...MVFR ceilings have developed over both
terminals and will persist through late morning with breezy
onshore flow. VFR through the remainder of the afternoon and early
evening with MVFR/IFR stratus ceilings returning near sunset.
&&
.MARINE...
(Tonight through next Saturday)
Issued at 929 PM PDT Sun Aug 9 2026
Fresh to strong northwest winds will persist through the middle
of the week with rough seas up to 12 feet over the northern outer
waters and occasionally the inner waters north of Point Reyes. The
San Pablo, Suisun Bays and the Delta will continue to see gusty
onshore winds through early Monday evening. The long period
southerly swells around 15 seconds will continue through much of
the work week.
&&
.FIRE WEATHER...
Issued at 1205 AM PDT Mon Aug 10 2026
Elevated fire weather conditions persist Monday across the higher
terrain due to an increase in onshore flow on the heels of very hot
and dry conditions. Slow improvement is expected with temperatures
still 10 degrees above normal and minimum relative humidity of 15%-
30% Monday afternoon. Gusts up to 30 mph can be expected through
gaps/passes and across ridgelines; namely, the Delta, Altamont Pass,
Pacheco Pass, and Interior Mountains of Monterey and San Benito
Counties. Moderate overnight recovery is expected Monday night;
however, the highest terrain of the Central Coast will likely remain
poor.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 2 AM PDT Thursday for CAZ006-506-
508-529-530.
PZ...Small Craft Advisory until 3 AM PDT Tuesday for SF Bay N of Bay
Bridge.
Small Craft Advisory until 3 AM PDT early this morning for Pt
Arena to Pt Reyes 0-10 nm.
Small Craft Advisory until 9 AM PDT Wednesday for Pt Arena to Pt
Reyes 10-60 NM.
&&
$$
SHORT TERM...Sarment
LONG TERM....Sarment
AVIATION...JM
MARINE...JM
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Prepared by Boulder-Creek.com Weather at: Mon Aug 10 04:30:02 PDT 2026
From the National Weather Service
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