FXUS66 KMTR 041140
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
440 AM PDT Sat Jul 4 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1200 AM PDT Sat Jul 4 2026

 - Marine layer stratus develops each evening and overnight before
   retreating to the coast each morning and afternoon

 - Temperatures near to slightly below seasonal averages for
   Independence Day

 - Temperatures dip for Sunday and Monday with a slight chance of
   showers on Sunday, warming trend for the mid to late week

&&

.SHORT TERM...
Issued at 1200 AM PDT Sat Jul 4 2026
(Today and tonight)

The marine layer stratus is continuing to make its way inland, as 
the clouds come into the Sonoma County valleys, the Richmond-
Berkeley area and down the Salinas Valley. Stratus will make its way 
into the coastal valleys through the night, retreating to the 
immediate coastal regions through the post-dawn and afternoon hours 
before returning this evening and overnight.

The weather pattern this Independence Day will be driven by a ridge 
set up over the Rocky Mountains and a shortwave trough that develops 
in the eastern Pacific, with California set up in a kind of 
transition zone between the two. Low temperatures remain in the 
lower to middle 50s in the lower elevations, and rise into the lower 
to middle 60s across the higher elevations. Today's highs are 
generally near to below the seasonal averages with highs in the 80s 
across the inland valleys, up to the lower to middle 90s in the 
warmest interior spots, the middle 60s to the upper 70s close to the 
Bays, and the middle 50s to lower 60s along the Pacific coast. Some 
breezy onshore winds develop in the afternoon and evening with gusts 
reaching 20 to 25 mph through gaps, passes, and the northern Salinas 
Valley. People planning to celebrate America's 250th birthday with 
fireworks or outdoor cookouts should remember their fire safety, 
obey any local burn bans, and keep a fire extinguisher nearby when 
playing with fireworks or cooking with open flames.

&&

.LONG TERM...
Issued at 1200 AM PDT Sat Jul 4 2026
(Sunday through Friday)

The long term outlook continues to show a balance between ridging 
across the Western United States and a series of troughs in the 
eastern Pacific through the next few days. A shortwave trough will 
knock down temperatures by a few degrees on Sunday with around five 
degrees of cooling within the inland valleys. In addition, as a 
pulse of moisture comes into the Bay Area and Central Coast, a few 
convective showers could develop Sunday morning and afternoon. High 
resolution convective models are showing the possibility for showers 
to come through the region, and the GFS K Index fields show a 
potential for isolated to widely scattered thunderstorms as the 
pulse of moisture comes through. However, with dry slots aloft, 
particularly near the 700 mb level (around 10,000 feet above sea 
level) and no obvious lifting mechanism besides local topography, 
confidence is not high enough to introduce probabilities for 
precipitation or thunder at this time. The oncoming day shift will 
reevaluate local conditions and make any grid modifications as 
necessary.

Monday will not have a chance for showers, but otherwise conditions 
should be similar to Sunday. Towards the middle and later parts of 
the week, temperatures will gradually rise inland as the ridge 
strengthens and moves into the Desert Southwest, with a particular 
emphasis on Wednesday and Thursday when local temperature gradients 
range from the lower to middle 60s at the immediate coast to the 
upper 80s to lower 90s in the inland valleys, to the triple digits 
up to 105 within the warmest spots of southern Monterey County. CPC 
outlooks continue to lean towards temperatures above seasonal 
averages into the middle of July.

&&

.AVIATION...
(12Z TAFS)
Issued at 436 AM PDT Sat Jul 4 2026

Rinse and repeat kinda morning with a similar stratus deck
covering the Bay Area. Once again, used a blend of persistence and
near term HRRR/HREF. Do expect VFR again this afternoon minus 
KHAF. Early return of stratus tonight. Conf Moderate to High.

Vicinity of SFO...CIGs hold 17-18Z. Gusty onshore develops by 
20-21Z.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...LIFR to MVFR through mid-late morning.
VFR this afternoon. Early return this evening. 

&&

.MARINE...
(Today through Thursday)
Issued at 436 AM PDT Sat Jul 4 2026

Northerly flow will remain over the coastal waters thanks to high
pressure anchored the north. Locally hazardous conditions will
persist over the outer waters north of Point Reyes through early
Sunday due to fresh to strong breezes. Sunday and into Monday
gentle to moderate breezes are expected. More widespread stronger
winds and seas will build starting Monday night and continuing
through the week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Sunday for Pt Arena to Pt 
     Reyes 10-60 NM.

&&

$$

SHORT TERM...DialH
LONG TERM....DialH
AVIATION...MM
MARINE...MM

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Prepared by Boulder-Creek.com Weather at: Sat Jul 4 06:30:03 PDT 2026