San Bruno, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

344
FXUS66 KMTR 141908
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1208 PM PDT Mon Jul 14 2025

...New SHORT TERM...

.KEY MESSAGES...
Updated at 1207 PM PDT Mon Jul 14 2025

 - Temperatures near to slightly below seasonal averages with a
   more noticeable cooling trend beginning Tuesday.

 - Localized elevated fire weather threat continues across the
   higher elevations.

 - Slight warming trend later this week into the upcoming weekend.

&&

.SHORT TERM...
Issued at 1207 PM PDT Mon Jul 14 2025
(This evening through Tuesday)

Visible satellite imagery is showing less cloud cover along the
coast then previously thought. This is as the marine layer is mixing
out thanks to southerly flow at the surface and more
westerly/northwesterly aloft. Afternoon temperatures will be similar
to those yesterday, upper 50s to lower 70s near the coast, 80s to
upper 80s just inland away from the coast, and 90s to near 100
degrees (very isolated in nature) in the far interior.

With the marine layer forecast to deepen tonight ahead of an
approaching mid/upper level trough, low clouds will spread back
inland into the coastal adjacent valleys. Coastal drizzle is also
likely as we have seen the past few days during the late night and
early morning hours on Tuesday.

Once low clouds dissipate across inland areas, temperatures will be
some 5-15 degrees cooler tomorrow afternoon in response to the
trough aloft. Maximum temperatures on Tuesday will be in the mid 70s
to mid 80s inland and the upper 60s to the mid 70s along the
Bayshore, with the coast remaining in the upper 50s to lower 60s.

From previous forecaster: "Localized elevated fire weather threat
continues across areas above and inland of the marine layer`s
influence. The combination of dry daytime humidities of around 20-
35%, poor overnight recoveries of 25-40%, and localized gusts to 25
mph will be the main factors behind the elevated threat. However,
the winds will remain onshore, leading to the fire weather threat
being diurnally driven, especially in the foothills where lighter
winds and good overnight recoveries are expected each night."

&&

.LONG TERM...
Issued at 1210 AM PDT Mon Jul 14 2025
(Tuesday night through Sunday)

A slight warming trend is expected heading towards the upcoming
weekend. Ensemble model cluster analysis does feature scenarios
where troughing and ridging develop over the northwestern United
States through the upcoming weekend. However, in terms of sensible
weather, most of the impacts from any deviation in the weather
pattern will be felt across the Pacific Northwest and northern
Rockies, with muted impacts across central California. Although
the exact details are still subject to variation, the current
forecast sees temperatures across the inland valleys rising to the
80s and lower 90s, up to the upper 90s in the warmest locations.

&&

.AVIATION...
(18Z TAFS)
Issued at 951 AM PDT Mon Jul 14 2025

Currently a mixed bag of LIFR-VFR at the terminals. An upper-level
shortwave trough will traverse across the region tonight. As a
result, the 1,400 feet deep marine layer is expected to deepen and
coastal drizzle can be expected. Tonight`s forecast could be a case
where ceilings come in low and then actually rise through the
morning. That being said, high confidence in all terminals
deteriorating to sub-VFR conditions tonight. While LVK only has a
20% chance, a deeper marine layer should help it getting there.
Smoke from wildfires burning in Northern California will likely
filter into the region and reduce slight range visibilities.

Vicinity of SFO...Currently VFR with northeasterly flow. Westerly
flow will return once the sea breeze kicks in this afternoon. High
confidence in sub-VFR ceilings returning tonight, likely on the cusp
of IFR/MVFR.

SFO Bridge Approach...The approach still has some low stratus this
morning, but that should evaporate very quickly. Low stratus clouds
will begin to filter in through the Golden Gate Gap by 00Z with
visuals likely being impacted through 18Z Tuesday.

Monterey Bay Terminals...Currently VFR and calm at MRY and IFR and
calm at SNS. High confidence in LIFR ceilings returning to both
terminals tonight.

&&

.MARINE...
(Today through Saturday)
Issued at 842 AM PDT Mon Jul 14 2025

Localized hazardous marine conditions in the form of strong
northerly breezes and very rough seas will be present through
tomorrow for the northern outer waters. Aside from that, a gentle
to moderate breeze with moderate to rough seas will prevail
through Friday.

&&

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

&&

$$

SHORT TERM...RGass
LONG TERM....DialH
AVIATION...Sarment
MARINE...Sarment

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