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
Visit us at www.weather.gov/sanfrancisco
Follow us on Facebook, X, and YouTube at:
www.facebook.com/nwsbayarea
x.com/nwsbayarea
www.youtube.com/nwsbayarea
Prepared by Boulder-Creek.com Weather at: Sat Jul 4 10:30:03 PDT 2026
From the National Weather Service
|