Technical NOAA Weather Discussion

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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Prepared by Boulder-Creek.com Weather at: Mon Jul 14 12:30:03 PDT 2025
From the National Weather Service