FXUS66 KMTR 260010
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
510 PM PDT Tue Aug 25 2026

...New AVIATION and MARINE...

.KEY MESSAGES...
Updated at 1242 PM PDT Tue Aug 25 2026

 - A shallow marine layer will keep coastal conditions near 
   normal through Thursday

 - Seasonably warm and very dry conditions continue above 1000 
   feet and across the far interior through Thursday

 - Pattern change Friday into the weekend brings cooler 
   temperatures and moderate potential for tropical moisture

&&

.SHORT TERM...
Issued at 1242 PM PDT Tue Aug 25 2026
(This evening through Wednesday night)

Regional satellite imagery is showing stratus retreating to the 
immediate Pacific coastline with abundant sunshine expected across
the interior this afternoon. Meanwhile, passing high clouds also 
persist and are moving northeastward across region. Thus, interior
temperatures will warm into the 80s to mid 90s and up to around 
105 deg F in the warmest interior parts of Monterey County. 
Persistent onshore and a shallow marine layer will keep 
temperatures near seasonal averages near the coast. Breezy onshore
winds are forecast to develop by this afternoon and evening, with
gusts up to 20 to 35 mph along the coast and in the favored 
valleys and passes. 

Tonight, expecting stratus to return inland late this evening and
into the interior valleys by Wednesday morning. However, the 
inland extent may be less than previous days as the marine layer 
compresses slightly. 

For Wednesday, a slight up tick in temperatures as the ridge 
builds further west across the Desert Southwest. As such, 
temperatures will be some 5-10 degrees F above average with 10-20 
degrees F above average in the far interior and higher elevations 
above 1000 feet. We are still expecting warm and very dry 
conditions above the marine influences with little to no overnight
humidity recoveries through Thursday. See the FIRE WEATHER 
section for the implications for local fire weather concerns. &&

.LONG TERM...
Issued at 1242 PM PDT Tue Aug 25 2026
(Thursday through next Monday)

Afternoon temperatures will be slightly cooler on Thursday as a 
trough of low pressure approaches the West Coast, however 850 MB 
temperatures will remain between 23-26 degree C. The cooling trend
will become more noticeable Friday and moreso into the upcoming 
weekend and early next week as the trough deepens over the Pacific
Northwest. Thursday night into Friday, we are expecting mid/upper
level tropical moisture to advect northward across the Bay Area 
and Central Coast. This will definitely increase high cloud cover 
and also result in an increased potential for high-based rain 
showers and/or thunderstorms. However, the lack of instability 
looks to be the limiting factor for thunderstorms. We are 
monitoring this closely at this time. 

Expecting breezier conditions with the deepening trough off of 
the West Coast. Gusts are forecast to be between 25 to 35 mph 
near the coast and in the favored valleys, gaps, and passes by 
Friday and into the weekend. By Monday, temperatures are forecast 
to be some 5-15 degrees F below seasonal averages which matches 
with the CPC's 6-10 Day Temperature Outlook. 

&&

.LONG TERM...
Issued at 1242 PM PDT Tue Aug 25 2026
(Thursday through next Monday)

Afternoon temperatures will be slightly cooler on Thursday as a 
trough of low pressure approaches the West Coast, however 850 MB 
temperatures will remain between 23-26 degree C. The cooling trend
will become more noticeable Friday and moreso into the upcoming 
weekend and early next week as the trough deepens over the Pacific
Northwest. Thursday night into Friday, we are expecting mid/upper
level tropical moisture to advect northward across the Bay Area 
and Central Coast. This will definitely increase high cloud cover 
and also result in an increased potential for high-based rain 
showers and/or thunderstorms. However, the lack of instability 
looks to be the limiting factor for thunderstorms. We are 
monitoring this closely at this time. 

Expecting breezier conditions with the deepening trough off of 
the West Coast. Gusts are forecast to be between 25 to 35 mph 
near the coast and in the favored valleys, gaps, and passes by 
Friday and into the weekend. By Monday, temperatures are forecast 
to be some 5-15 degrees F below seasonal averages which matches 
with the CPC's 6-10 Day Temperature Outlook. 

&&

.AVIATION...
(00Z TAFS)
Issued at 443 PM PDT Tue Aug 25 2026

The stratus deck remains off the immediate coast at this hour with
an onshore flow eager to help usher it back to the coast this
evening and into the overnight hours. We are anticipating the
return of coastal low clouds tonight with limited inland intrusion
through the gaps and bays as the marine layer will remain
moderately shallow between 1000-1500 feet. IFR to LIFR cigs
already impacting HAF with cigs expected at MRY, and SNS around 
sunset. Low confidence on whether SJC will develop a ceiling. 

Vicinity of SFO...VFR conditions prevail with moderate west winds.
Winds will ease becoming light overnight. IFR cigs expected to
develop overnight with moderate confidence on timing. 

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR conditions prevail with moderate 
west winds. Winds will ease becoming light overnight. IFR cigs 
expected around sunset this evening. Cigs expected to drop to 
LIFR overnight with reduced visibility. Clearing forecast between 
18-19z Wednesday morning.


&&

.MARINE...
(Tonight through next Sunday)
Issued at 200 PM PDT Tue Aug 25 2026

Northwest moderate breezes with strong gusts continue today as 
moderate wind driven seas prevail through the week. Northwest winds 
become fresh to strong by Wednesday into the weekend. A long period 
southerly swell approaches our coastal waters by the end of the week.


&&

.FIRE WEATHER...
Issued at 1202 AM PDT Tue Aug 25 2026

Near-critical fire weather conditions continue through Thursday for 
elevations above 1000 feet as warm and dry conditions continue 
across the region. Humidity recoveries remain poor to very poor in 
the higher elevations, with nocturnal drying expected within the 
Santa Lucia range. Breezy conditions will develop each afternoon and 
evening, but not for a long enough period to trigger any fire 
weather products. Specifically regarding the Timber Fire vicinity, 
observational data suggests that southwesterly winds from the 
Pacific Ocean over the ridgetops are helping to moisten the air, 
with nocturnal drying being observed as the winds diminish and even 
turn faintly offshore overnight. This has led to an unusual 
situation where daily maximum relative humidity values have been 
observed during the daytime. Smoke transport from the Timber Fire 
will continue to peak in the afternoon and evening with the plume 
spreading towards the Salinas area. Friday into the weekend, a 
pattern change should allow for some relief as an upper level trough 
comes into the region bringing cooler temperatures and a deeper 
marine layer.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 AM PDT Thursday for Pigeon Pt to Pt 
     Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt 
     Piedras Blancas 0-10 nm.

     Small Craft Advisory from 9 PM this evening to 9 AM PDT Thursday 
     for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10-
     60 NM.

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...CW
MARINE...Navarrete

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Prepared by Boulder-Creek.com Weather at: Tue Aug 25 20:30:03 PDT 2026