FXUS66 KMTR 050446
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
946 PM PDT Sat Jul 4 2026
...New AVIATION...
.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)
&&
.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...
(06Z TAFS)
Issued at 936 PM PDT Sat Jul 4 2026
Stratus is moving back in this evening and has already made it to
some of the terminals. It is expected to continue to expand
overnight bringing mainly IFR conditions with some local areas of
LIFR. Generally CIGS are expected to be similar in height to
early Saturday morning. Sunday the clearing is expected to be
similar as well with most sites clearing by mid to late morning.
The immediate coast will likely remain MVFR with only a few short
breaks expected in the afternoon.
Vicinity of SFO...SCT-BKN high clouds continue through tonight and
likely into Sunday. Stratus is expected to return around 08Z
tonight, although the high clouds are making it difficult to
monitor. Clearing may be slightly later than on Saturday, but
still expect VFR conditions by 17 or 18Z. Breezy onshore winds
are expected once again in the afternoon near 20 kts at times.
Sunday night the MVFR CIGS (locally IFR) are expected to return
from around 07-18z once again with moderate confidence in cig
timing.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...SCT-BKN high clouds through the period.
IFR (locally LIFR) cigs return near or after 02z Sun, clearing is
expected again Sunday mid to late in the morning with moderate
confidence in timing. Breezy onshore winds are expected again
Sunday afternoon near 15 kts at times. Sunday evening a quick
return of stratus is expected like we have been seeing.
&&
.MARINE...
(Tonight through next Thursday)
Issued at 224 PM PDT Sat Jul 4 2026
Northerly flow will remain over the coastal waters over the
weekend. Locally hazardous conditions will persist over the outer
waters north of Point Reyes through early Sunday due to fresh to
strong breezes. Calmer winds are expected later on Sunday and into
Monday. A better chance for small craft winds will occur for many
areas by Monday night into much of next week with building seas.
&&
.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...MKK
MARINE...MKK
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Prepared by Boulder-Creek.com Weather at: Sat Jul 4 22:30:03 PDT 2026
From the National Weather Service
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