FXUS66 KMTR 101131
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
431 AM PDT Mon Aug 10 2026

...New AVIATION, MARINE...

.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...
(12Z TAFS)
Issued at 431 AM PDT Mon Aug 10 2026

Coastal stratus and fog /MVFR-IFR-LIFR/ continue to redevelop and
onshore winds are at least partially ushering stratus and fog inland
this morning. More recently the marine layer is showing signs of 
deepening to 1300 to 1800 feet. Stratus and fog will mix out by 
late morning with VFR prevailing through the afternoon. Stratus 
and fog /MVFR-IFR-LIFR/ redevelop tonight and Tuesday morning.

Vicinity of SFO...Stratus is currently north of SFO. VFR is forecast
to continue at the terminal. West to northwest wind 5 to 15 knots
except 15 to 25 knots in the afternoon and evening. 

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Stratus /IFR-LIFR/ will mix out to VFR by
late morning with VFR continuing through the afternoon. Stratus /IFR-
LIFR/ redevelops and moves inland tonight and Tuesday morning. West
to northwest winds 5 to 15 knots.

&&

.MARINE...
(Today through Saturday)
Issued at 407 AM PDT Mon Aug 10 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 this 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 9 PM PDT this evening for SF Bay N of 
     Bay Bridge.

     Small Craft Advisory until 9 AM PDT Wednesday for Pt Arena to Pt 
     Reyes 10-60 NM.

&&

$$

SHORT TERM...Sarment
LONG TERM....Sarment
AVIATION...Canepa
MARINE...Canepa

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Prepared by Boulder-Creek.com Weather at: Mon Aug 10 10:30:02 PDT 2026