Russell City, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

436
FXUS66 KMTR 060555
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
955 PM PST Fri Dec 5 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 1215 PM PST Fri Dec 5 2025

 - Persistent forecast through the next seven days with benign
   conditions and no precipitation expected

 - Impacts from Tule Fog in the North Bay and interior East Bay
   valleys

 - Next chance for rain towards the middle of the month

&&

.UPDATE...
Issued at 924 PM PST Fri Dec 5 2025

Updated the overnight low temperatures and issued a Cold Weather
Advisory for most of the North Bay. Temperatures across the North
Bay are generally running a few degrees cooler than at this time
last night with Petaluma dropping to 37 around 8pm. The Tule Fog
has struggled making progress westward into our area so far
tonight. Also, a subtle return of the marine layer is helping to
produce stratus along northwest facing areas of the coast from
Bodega Bay south to Pescadero. Otherwise, the forecast remains on
track for the remainder of the Bay Area and Central Coast.

&&

.SHORT TERM...
Issued at 1259 PM PST Fri Dec 5 2025
(This evening through Saturday)

Owing to the slower than expected stratus mix out and warming in
the valleys of the North Bay and interior East Bay, have opted to
decrease today`s highs and tonight`s lows in both areas, with the
high temperatures now expected to rest in the middle to upper 50s
and lows in the upper 30s to lower 40s in the area, with areas in
the eastern tier of Contra Costa County going up to the lower 50s
today.

For all other regions, the previous discussion is still valid: Satellite
imagery reveals lingering impacts from the Tule Fog spillover
across the valleys of the North Bay and the interior East Bay. The
mix out process continues to be rather slow with marginal
shrinkage of the stratus deck in the late morning, with the bulk
of the mixing out expected to occur this afternoon into the
evening. There is also a potential for drizzle to develop in the
coastal waters tonight, fringe effects of a storm system that is
bringing rain to the Pacific Northwest but is not expected to
bring any precipitation on the land side of the Bay Area and
Central Coast. This, in turn, could support the return of coastal
stratus to the region. Otherwise, the weather remains generally
clear through the day, as upper level ridging dominates the
western United States. High temperatures today and Saturday range
from the lower to middle 60s across the inland valleys, with the
southern Salinas Valley reaching the upper 60s to near 70, and the
upper 50s and the lower 60s near the coast. Lows will generally
range from the lower to middle 40s inland and the middle to upper
40s along the coast. Some locations in southern Monterey County
will drop into the middle 30s. Will need to monitor the need for a
Cold Weather Advisory if the temperatures drop due to enhanced
radiational cooling, or if temperatures in the North and East Bays
stay cool due to lingering stratus impacts reducing the daytime
heating effects.

&&

.LONG TERM...
Issued at 1215 PM PST Fri Dec 5 2025
(Saturday night through next Thursday)

Ridging will dominate the weather patterns through the rest of the 7-
day outlook, enabling a gradual warming trend across the region.
Rather than a day when the temperatures shoot upwards, we will
experience a extended crescendo where the highs shoot up by a degree
or two each day until you notice that by the middle of next week,
temperatures are running 5 to 10 degrees above seasonal averages and
highs in the inland valleys have reached the upper 60s to middle
70s. By the end of the 7-day forecast period, there are hints that a
burst of offshore flow could come to the region, although exactly
how strong that flow will be is open to lots of refinement.

Longer range model guidance suggests a possible change in the
weather pattern towards the middle of the month. Ensemble model
cluster analysis depicts the majority of model runs showing a
continuing ridge, but substantial minorities (somewhere around 30-
40% of the ensemble members) depict a breakdown of the ridge. CPC
guidance continues to show a slight lean, emphasize, a slight lean,
towards precipitation totals above seasonal averages for December 13-
19 across the Bay Area. For context, within the long-term climatic
averages, downtown San Francisco receives a little over an inch of
rain during this period.

&&

.AVIATION...
(06Z TAFS)
Issued at 953 PM PST Fri Dec 5 2025

An odd mixture of stratus along the coast and IFR/Tule fog moving
into eastern portions of the CWA. Leaned on HREF guidance to capture
stratus moving in along the coast with moderate confidence that
stratus/MVFR conditions will persist through much of the overnight
period. For areas impacted by stratus, not anticipating visibilities
to drop much. For areas impacted by Tule Fog, visibilities will be
around 1-2SM with the potential for dense fog (1/4SM) to develop in
the North Bay. APC is likely to see some impact from Tule Fog
tonight but confidence is lower as to how long fog will be over the
airport. Followed persistence forecast for the timing of when
conditions will improve tomorrow (generally looking at late
morning/early afternoon clearing). Moderate onshore winds redevelop
tomorrow afternoon/evening before weakening and becoming variable to
lightly offshore overnight.

Vicinity of SFO...MVFR through much of the overnight period. Models
did not have a good grasp on the reemerging marine layer and
accompanying marine stratus tonight with only HREF guidance showing
the stratus that is currently over SFO. HREF guidance keeps low
clouds in the vicinity of SFO through the rest of tonight so opted
to utilize the HREF timing. Not anticipating fog to develop at SFO
with CIGs expected to predominantly be on the MVFR-IFR border
overnight. Winds remain light and slightly offshore overnight before
more moderate onshore winds return during the day tomorrow.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR. HREF guidance is best depicting the
current marine stratus setup with stratus to stay offshore tonight.
There is some potential for low clouds to reach MRY after 12Z but no
major impacts are expected at the airport. Winds remain light
overnight before more moderate onshore winds return during the
afternoon.

&&

.MARINE...
(Tonight through next Thursday)
Issued at 924 PM PST Fri Dec 5 2025

Northwesterly winds have increased to fresh to strong offshore
with  localized near gale force gusts possible across the outer
waters. Winds remain elevated through the weekend and into next
week but  there may be brief periods where winds weaken across the
coastal  waters. Moderate seas with wave heights between 6 to 8
feet continue  through the weekend. Moderate, long-period
northwesterly swell  returns by mid next week with wave heights to
build.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 3 PM PST Sunday for CAZ006-506-508-
     529-530.

     Cold Weather Advisory until 8 AM PST Saturday for CAZ502-504-506.

PZ...Small Craft Advisory until 3 AM PST Saturday for Pt Arena to Pt
     Reyes 0-10 nm.

     Small Craft Advisory from 9 AM Saturday to 3 AM PST Sunday for
     Pt Pinos to Pt Piedras Blancas 0-10 nm.

     Small Craft Advisory until 9 AM PST Saturday for Pt Arena to Pt
     Reyes 10-60 NM.

     Small Craft Advisory until 9 AM PST Sunday for Pigeon Pt to Pt
     Pinos 10-60 NM.

&&

$$

SHORT TERM...DialH
LONG TERM....DialH
AVIATION...Kennedy
MARINE...Kennedy

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