FXUS66 KMTR 041910
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1210 PM PDT Sat Jul 4 2026
...New SHORT TERM, LONG TERM...
.KEY MESSAGES...
Updated at 1208 PM 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 1208 PM PDT Sat Jul 4 2026
(This evening through Sunday night)
Typical marine stratus is retreating to the coast early this
afternoon with mostly sunny conditions across the interior for
Independence Day. However, high clouds are streaming in from the
southwest as a weak shortwave trough approaches the region. More on
this later.
Today's forecast temperatures look to be near or slightly below
seasonal averages. Maximum afternoon temperatures are forecast to be
in the upper 50s to lower 60s near the immediate coastline, middle
60s to upper 70s just inland from the coast/bays, and 80s to lower
90s across the inland valleys. Breezy onshore flow is forecast to
return this afternoon with wind gusts approaching 20 to 25 mph
through the gaps, passes, and Salinas Valley. From the previous
forecaster: "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."
Stratus is likely to return late this afternoon near the coast,
spreading through the Golden Gate into the evening (if they manage
to clear out at all this afternoon), and into the inland valleys
overnight and into early Sunday morning. Moisture associated with
the aforementioned shortwave trough will continue to advect across
the region overnight and into Sunday morning as the feature moves
inland. Thus, there is generally less than a 15% chance of high-
based convection across the region with less than 5% probability of
thunderstorms from midnight through about 12 p.m. Sunday. However,
the missing ingredient appears to be a lifting mechanism as Most
Unstable CAPE remains less than 100 J/kg based off of convection-
allowing models (CAMs). We will continue to monitor this closely and
update the forecast accordingly. Tomorrow will feature cooler
temperatures thanks to the high clouds moving across the region and
look to be 5-15 degrees (especially across the interior valleys)
below early July averages.
&&
.LONG TERM...
Issued at 1208 PM PDT Sat Jul 4 2026
(Monday through next Friday)
The shortwave feature will be exiting the region by Monday with
dry conditions and a gradual warming trend to resume throughout
midweek. This will be as high pressure strengthens over the Desert
Southwest with temperatures expected to be the warmest Wednesday
and Thursday. We are expected afternoon temperature to range from
the lower to middle 60s at the immediate coast (thanks to
continued marine influences), upper 70s to middle 80s just inland
away from the coast/bays, upper 80s to lower 90s in the inland
valleys, and up to 105 within the warmest spots of southern
Monterey County. Weak troughing returns toward the later half of
the week cooling temperatures ever so slightly.
&&
.AVIATION...
(18Z TAFS)
Issued at 1032 AM PDT Sat Jul 4 2026
Morning low clouds scattering out this morning out of most
terminals, minus KHAF today. SCT-BKN high clouds near 20k ft and
diurnal winds expected through the TAF period. MVFR/IFR cigs & vis
for many return this evening; scattering occurs again by mid
morning on Sunday.
Vicinity of SFO...SCT-BKN high clouds through the period with
breezy onshore winds this afternoon near 20 kts at times. MVFR
(locally IFR) cigs 07-18z with moderate confidence in cig timing.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...SCT-BKN high clouds through the period
with breezy onshore winds this afternoon near 20 kts at times. IFR
(locally LIFR) cigs return after 02z Sun, clearing near the end
of the TAF period with moderate confidence in timing.
&&
.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...RGass
LONG TERM....RGass
AVIATION...APR
MARINE...APR
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 12:30:02 PDT 2026
From the National Weather Service
|