FXUS66 KMTR 130131
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
531 PM PST Mon Jan 12 2026

...New UPDATE...

.KEY MESSAGES...
Updated at 141 PM PST Mon Jan 12 2026

 - Hazardous conditions at Pacific Coast Beaches

 - Above normal warmth for the next 6 to 10 days

&&

.UPDATE...
Issued at 524 PM PST Mon Jan 12 2026

There's hardly a cloud in the sky across California this evening.
With the benign weather ongoing there are really only 2 questions
to focus on tonight. How cold will it get, and will fog form? 
Both of these will depend heavily on the strength of the offshore 
wind. The current SFO-WMC gradient is -10.9 mb. No models have the
offshore gradient analyzed that strong. Many aren't even close. 
This suggests that the model guidance is overdoing the fog chances
and temperature drop tonight. Both of these will be moderated by 
low level mixing and adiabatic downslope warming. 

&&

.SHORT TERM...
Issued at 141 PM PST Mon Jan 12 2026
(This evening through Tuesday)

Largely quiescent conditions are forecast tonight and into the 
day on Tuesday. Current water vapor imagery shows ridging across 
the Pacific Southwest. A plume of mid/upper level moisture will 
stream in from the Central Pacific, but be largely deflected to 
our north. While this conveyor of moisture may send a few 
mid/upper level high clouds across our region, we'll see 
negligible impacts from this feature.

The dry airmass coupled with winds below 10 mph and mostly clear 
skies will support ideal radiational cooling, particularly in the
valleys. Taking a look at the past couple of days, our valley 
locations have been averaging just below some of the median 
blended guidance. While the airmass continues to gradually modify,
it does appear that we'll have to contend with another night of 
impactful cold. A Cold Weather Advisory has been posted for some 
of our valley locales that will likely experience optimal 
radiational cooling. Be sure to tend to sensitive 
crops/vegetation, tend to any pets/livestock that are sensitive to
the cold, and be mindful/judicious regarding indoor heating 
appliances.

After what should be our last chilly morning, Tuesday (and really
onward) appears picture perfect weather wise for outdoor 
activities. If you're headed to the beach, please be sure to 
exercise caution as long period (above 15 second) westerly swell 
will arrive along our shoreline. The energetic surf zone will 
feature an enhanced risk for sneaker waves and rip currents. Be 
sure to check conditions if headed to the beach. Otherwise, high 
temperatures will run around 5 to 10 degrees above normal for this
time of year. 

&&

.LONG TERM...
Issued at 141 PM PST Mon Jan 12 2026
(Tuesday night through next Sunday)

The long term forecast period remains rather uneventful as it 
pertains to the sensible weather elements. A series of potent 
storm systems will continue to generate favorable swell that will 
impact our shorelines. This translates to a continued risk for 
hazardous beach conditions. Given the holiday weekend and very 
nice weather, we'll continue to advertise a threat for sneaker 
waves and rip currents. Be sure to check water conditions before 
venturing out!

The 6 to 10 day outlook calls for above normal warmth and above 
normal precipitation. Digging into the tercile data, the breakdown
is quite stark, with over 70% probabilities for above normal 
warmth across much of the area. This is courtesy of mid-level 
ridging becoming anchored across our region. The lack of onshore 
flow (with brief bursts of offshore flow) will allow for a larger 
diurnal temperature range. While there's a non-zero risk for MinTs
to near "impactful" levels, the airmass should remain rather 
stagnant, with no real sources of cold or warm air advection. 
Beyond the 10 day period, there are some hints at a pattern shift.
Some camps in our model suite of over 200 pieces of guidance 
break down the upper ridge quickly in favor of more 
troughing/onshore flow. Other guidance keeps the ridge in place a 
little longer. While these details will be ironed out over the 
next several days, it does appear that at least a brief period of 
more active weather may be in store as we approach the end of the 
month. 

&&

.AVIATION...
(00Z TAFS)
Issued at 322 PM PST Mon Jan 12 2026

VFR conditions continue to dominate with gentle winds. The exception 
is at STS and HAF, where localized fog and mist are expected Sunday 
morning. The rest of the terminals have a slight chance of fog 
formation. The dew points are a few degrees higher than this time 
yesterday, with similar temperatures. That gives us a better 
starting point for the air to reach saturation. Offshore winds 
will be similar to this morning, however, which should help mix 
the lower atmosphere enough to keep the visibility unrestricted.

Vicinity of SFO...VFR conditions will prevail through the evening
with light NE winds. There is a chance for visibility restrictions
Tuesday morning, specifically 30% chance for MVFR, 15% chance for
IFR, and a 10% chance for LIFR. VFR conditions are still most
likely, but it's not a guarantee through the morning hours.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...High confidence in VFR conditions at both
MRY and SNS through the TAF period as the offshore winds will be 
strong enough to mix out any mist or fog. 

&&

.MARINE...
(Tonight through next Saturday)
Issued at 322 PM PST Mon Jan 12 2026

Gentle to moderate northerly breezes over the waters through
Wednesday thanks to offshore high pressure. The longer period
swell will continue to subside through Tuesday with an improved
sea state. Another longer period westerly swell will arrive late
Wednesday bringing an elevated sea state.

&&

.BEACHES...
Issued at 141 PM PST Mon Jan 12 2026

While the Beach Hazards Statement expires tonight, a seires of
long period swell groups will hazardous beach conditions with 
increased risks for rip currents, sneaker waves, and larger shore 
break. Hazardous beach conditions are expected to continue through
Thursday.

Be sure to check conditions before heading to the beach. Stay off
of jetties, piers, rocks, and other waterside infrastructure. 
Remain out of the water to avoid hazardous surf and NEVER turn 
your back on the ocean. Monitor local weather, surf and tide 
forecasts at www.weather.gov/mtr. 

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement until 7 PM PST this evening for CAZ006-
     505-509-529-530.

     Cold Weather Advisory from 1 AM to 9 AM PST Tuesday for CAZ506-
     510-516-518.

PZ...None.
&&

$$

SHORT TERM...Bain
LONG TERM....Bain
AVIATION...Flynn
MARINE...MM

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Prepared by Boulder-Creek.com Weather at: Mon Jan 12 20:30:03 PST 2026