FXUS66 KMTR 081738
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1038 AM PDT Thu Oct 8 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1259 PM PDT Wed Oct 7 2026

 - Hot inland temperatures continue Thursday

 - Sharp cool-down this weekend and early next week

 - Coastal flooding during high tides and large swell this 
   weekend

 - Light rain possible early next week

&&

.UPDATE...
Issued at 907 AM PDT Thu Oct 8 2026

Fog has begun to lift across coastal locations of the North Bay, 
San Francisco, and the San Francisco Peninsula this morning. 
However, areas of dense fog persist around the Monterey Bay and 
adjacent inland zones. Thus, have extended the Dense Fog Advisory 
through 10 AM in these areas with the anticipation of daytime 
heating to take over and improve visibilities. Otherwise, the Heat
Advisory remains in effect for the interior through 10 PM this 
evening for all areas away from the immediate coastline. 

RGass

&&

.SHORT TERM...
Issued at 1155 PM PDT Wed Oct 7 2026
(Tonight through Sunday)

Strong 500 mb high pressure ridging bringing inland areas hot 
and dry weather will continue into Thursday. Well above early
October normal temperatures occurred again today, though none of
the long term stations set any new record highs today. The Heat
Advisory (WMO header WWUS76) for inland areas continues through 
10 pm PDT Thursday. And a reminder there is a Coastal Flood 
Advisory (WHUS36) for anomalous high tides with up to 1.2 feet of
inundation above ground level in low-lying areas.

As mentioned it'll be hot again inland Thursday while cooler 
temperatures will prevail along the immediate coastline within a 
compressed marine layer. NBM forecast highs were nudged downward
slightly for much of the immediate coastline for Thursday. Global
models continue to indicate a major pattern shift will take place
over the western states beginning later tomorrow through Friday. 
A weak 500 mb low ~ 900 miles to our west will progress toward our
forecast area allowing part of the aforementioned 500 mb high 
pressure ridge to slip westward (retrogressing) far to our west.
Separate strengthening 500 mb troughing will take place over the 
Pacific Northwest; long wave troughing will begin to replace long 
wave ridging over the west. Mid-latitude amplification and winds 
will move the 500 mb trough southward, decidedly shifting the pattern
south and east including the near term weak 500 mb low just out 
ahead of it and the rest of the 500 mb ridge. This pattern shift 
will bring in much cooler air from the surface up through 500 mb 
across the forecast area through the weekend.

Winds will become gusty over the coastal waters and gap winds will
increase as well during the weekend, both Saturday and perhaps Sunday
with gusts possibly nearing wind advisory level in the usual wind
favored gaps across the San Francisco Peninsula and the East Bay.

&&

.LONG TERM...
Issued at 1155 PM PDT Wed Oct 7 2026
(Sunday night through next Wednesday)

Winds over land diminish later Sunday. There may be some residual
moisture the cold core low will tap producing a few showers over 
the southern forecast area later Sunday and Monday. Otherwise dry
and much cooler weather is forecast later Monday, Tuesday and 
Wednesday. Daytime highs and lows will shift to below normal.
Daytime highs will generally be in the 60s coast to the 70s
inland. Night-time and morning lows will mostly be in the 40s 
except around 50 at the coast and as cold as the 30s far inland 
valleys.

&&

.AVIATION...
(18Z TAFS)
Issued at 1037 AM PDT Thu Oct 8 2026

Patchy fog and LIFR stratus lingers at the immediate coast with the 
rest of the region remaining VFR through the daytime. A gentle to 
moderate onshore pattern wind develops in the afternoon and 
evening hours. This evening and tonight, the marine layer is 
expected to rebuild and thicken as large scale ridging moves 
eastwards, allowing for some improved inland expansion of the 
stratus deck. Forecast confidence is moderate for stratus extent 
and ceiling heights, but expect some inland development into the 
North bay valleys, SF Bay, and Salinas Valley overnight. Stratus 
begins to retreat back to the coastal regions Friday morning.

Vicinity of SFO... Moderate confidence for VFR conditions through 
the TAF period with some scattered clouds possible late tonight. 
Higher confidence in stratus impacts at OAK. Moderate west-northwest 
winds will develop in the afternoon and evening hours, with light 
winds overnight into the morning.

SFO Bridge Approach... Similar to SFO

Monterey Bay Terminals... Lingering fog and LIFR stratus is expected 
to lift imminently at MRY but potentially persist through the 
afternoon along the immediate coast. Otherwise VFR conditions remain 
prevalent through the day with gentle to moderate northwest winds in 
the afternoon hours. IFR-LIFR stratus develops this evening with 
moderate confidence for fog, not expected to clear out until the TAF 
period ends on Friday morning, or shortly thereafter.

&&

.MARINE...
(Today through Tuesday)
Issued at 907 AM PDT Thu Oct 8 2026

Moderate to fresh northwesterly breezes and moderate seas will
prevail today. Conditions deteriorate Friday and into the weekend
as northerly breezes increase to become strong to near gale across
the coastal waters, Monterey Bay, and through the Golden Gate
Gap. Gale force gusts are expected across the northern outer
waters and the coastal jet region of Point Reyes. These winds will
build rough to very rough seas. Long period southerly swell
arrives Friday, with long period northwesterly swell arriving
Sunday, creating a confused sea state.

&&

.FIRE WEATHER...
Issued at 428 AM PDT Thu Oct 8 2026

Hot and dry conditions will lead to elevated fire weather conditions 
across the interior and higher terrain Thursday. Temperatures 10 to 
20 degrees above normal and poor minimum relative humidity will 
continue away from the compressed marine layer at the coast 
Thursday. The higher terrain will experience active thermal belting, 
little-to-no recovery with nocturnal drying across the highest 
peaks, and thus prolonged burn periods. Winds remain the limiting 
factor, with diurnal winds prevailing except for light 
northerly/offshore flow overnight across the higher terrain. Even 
though conditions become cooler and more humid Friday, windier 
conditions will keep elevated fire weather conditions across the 
interior and higher terrain through Friday.

Sarment

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory from 9 AM Friday to 3 PM PDT Tuesday for 
     CAZ006-508-529-530.

     Heat Advisory until 10 PM PDT this evening for CAZ503-504-506-
     508-510-512>518.

     Coastal Flood Advisory until 4 PM PDT Wednesday for CAZ506.

PZ...Small Craft Advisory from 3 AM to 3 PM PDT Friday for Pt Arena 
     to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...Canepa
LONG TERM....Canepa
AVIATION...DialH
MARINE...DialH

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Prepared by Boulder-Creek.com Weather at: Thu Oct 8 12:30:02 PDT 2026