Technical NOAA Weather Discussion

FXUS66 KMTR 131139
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
339 AM PST Fri Feb 13 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 305 AM PST Fri Feb 13 2026

 - Hazardous beach conditions continue through early Saturday
   morning

 - Widespread rain and gusty winds return late Saturday and 
   continue through much of next week

 - Temperatures drop starting early to mid next week as a colder
   airmass moves in

&&

.SHORT TERM...
Issued at 305 AM PST Fri Feb 13 2026
(Today and tonight)

Foggy conditions have started developing across portions of the 
North Bay Valleys and in the vicinity of the SF Bay Shoreline. Given 
the lack of cloud cover across the interior, there is the potential 
for patchy fog to develop across portions of the Santa Clara Valley 
and East Bay Valleys as well. Stratus is likely to be more 
widespread across the region tonight with coastal sites such as Half 
Moon Bay and Monterey reporting cloud ceilings around 1000 ft. 
Overcast skies should clear by late morning/early afternoon before 
returning again Friday night. Morning temperatures will be chillier 
than over the last few days with lows in the low to mid 40s across 
much of the region while the interior Central Coast drops into the 
30s. It will be a chilly start to the day but, fortunately, the 
afternoon will be seasonably warm with highs in the low to mid 60s. 
Today is last fully dry day of our brief respite from the rain. Take 
advantage of the day and finish up any outdoor preparations today or 
Saturday morning before we kick off our upcoming rain event late 
Saturday.

&&

.LONG TERM...
Issued at 305 AM PST Fri Feb 13 2026
(Saturday through Thursday)

Another chilly morning is on the books on Saturday with morning 
temperatures in the low to mid 40s while the interior Central Coast 
drops into the 30s. Saturday acts as a transition day from dry to 
wet weather as a deep upper level trough from the Gulf of Alaska 
pushes in and displaces the upper level ridge to our east. While 
rain chances don't increase until late Saturday, high level clouds 
are expected to build in throughout the day ahead of the troughs 
arrival. This will keep high temperatures slightly cooler (North Bay 
and elevated terrain) in the 50s to about the same (rest of the 
region) in the low 60s on Saturday as on Friday. If not taken care 
of previously, Saturday morning/afternoon is your best time to take 
care of any remaining outdoor preparations like cleaning the gutter, 
securing outdoor objects, or making sure drains are clear before the 
rain returns. 

Models are coming into agreement that rain will reach the region 
late Saturday evening and will continue through much of next week. 
That is not to say there won't be any breaks or dry periods this 
week as models show this unfolding as multiple rounds of 
precipitation. From Saturday evening to next Friday, 3-5" of rain is 
expected across the interior while 4-6" of rain is expected across 
the coastal mountain ranges. The bulk of this rain will fall in the 
Sunday to Wednesday time frame as a surface low pressure system 
develops offshore and moves inland over the Bay Area. As we head 
into Monday/Tuesday, a colder airmass will advect southwards towards 
the Bay Area/Central Coast as a deep upper level trough pushes in 
from the Gulf of Alaska and merges with the original trough over the 
West Coast. The arrival of this second trough will bring additional 
rounds of rain through the end of the week. Flooding concerns will 
initially start out low but are expected to increase with each day 
of successive rainfall as the soils become more saturated. Flooding 
is largely expected to be nuisance (i.e. ponding on roadways or low 
lying areas prone to flooding) with mainstream river flooding not 
expected at this time. A marginal risk of excessive rainfall has 
been issued for Monday along the Central Coast and South Bay. 
Embedded thunderstorms remain possible this week but confidence is 
on the lower end. In terms of thunderstorm ingredients we look for a 
source of lift, a source of moisture, good low level shear, and 
instability. Our surface cold front will provide us with a source of 
lift and we do have decent moisture/MUCAPE on Monday and Tuesday. 
However, the low level shear does not look to be quite as 
impressive. While the low-level jet stream does impact our CWA, the 
upper level support is lacking in terms of the wind as the 200mb jet 
stream is located farther south over Southern California. In order 
for our thunderstorm chances to increase we would need the surface 
low pressure system to shift farther northwards as it moves onto 
land. 

Southerly winds strengthen across the region Sunday into Tuesday 
with gusts between 30-40 mph likely. A Wind Advisory will likely be 
needed for the coastline in the Monday-Tuesday period as the surface 
low moves inland. Probabilistic guidance shows a 50-60% chance of 
gusts above 40 mph along the Monterey Bay Region and an 80% chance 
across coastal Monterey County (Big Sur extending southwards to SLO 
county line). Another concern with this system is that temperatures 
drop starting Monday as the cooler airmass from the Gulf of Alaska. 
High temperatures will be seasonably cool in the upper 40s to 50s 
with the highest elevations peaking in the low to mid 40s. Morning 
low temperatures will get progressively colder each night with 
widespread lows in the 30s across the interior. Coastal areas will 
be chilly but remain slightly insulated and only drop into the low 
40s (potentially the upper 30s if some of the colder scenarios play 
out). A mix of Cold Weather Advisories and Extreme Cold Warnings are 
likely to be needed next week after this airmass arrives. As an 
example of how cold this airmass is, the 12Z OAK sounding for 2/17 
has a mean 850mb temperature of 5.1C. Model guidance is showing an 
850 mb temperature of -3C at 12Z on 2/17 which would put it in the 
bottom 10% of 850 mb 12Z temps for 2/17. If you have any plants that 
are sensitive to the cold it would be a good idea to move them 
indoors this week, keep pets indoors overnight, and check on any 
neighbors who are sensitive to the cold. With the combination of 
cooler air temperatures and lingering moisture, we will see a drop 
in snow levels and a few flakes may be possible across the highest 
peaks of Mt. St. Helena, the Santa Lucia Range, and the Gabilan 
Range.

&&

.AVIATION...
(12Z TAFS)
Issued at 339 AM PST Fri Feb 13 2026

Patchy MVFR-LIFR stratus has developed along the coast and parts of 
the North Bay valleys, the East and South Bay, and portions of the 
interior Central Coast. The evolution of the stratus has been hard 
to predict through the night, but the general trend is for the 
stratus layer to expand across the region through sunrise and 
persist well into the post-dawn hours, with clearing times expected 
around 16-20Z. Confidence for clearing times is low in the coastal 
regions as some high resolution model data keeps coastal terminals 
socked in. Gentle to moderate onshore flow will develop this 
afternoon. Stratus will return overnight, but the evolution is 
rather uncertain with the model outputs disagreeing both with each 
other and with some of the observations so far tonight. The best 
guess is for a rather early return of stratus along the Pacific 
coast near 00Z (assuming that clearing to VFR does happen later 
today), followed by progressive development of the stratus layer 
through the evening and overnight hours.

Vicinity of SFO... IFR stratus has been impacting the terminal 
through the course of the night, but no consistent ceiling has 
developed over the terminal. Moderate confidence for consistent IFR 
ceilings to develop at some point this morning, with clearing 
expected around 18-19Z as breezy west winds develop. MVFR-IFR 
stratus returns to the terminal overnight into Saturday morning with 
moderate confidence in the clearing time. 

SFO Bridge Approach... Monitoring a patch of stratus to the east of 
the SF Bay for potential impacts to the approach path tonight. 
Otherwise similar to SFO.

Monterey Bay Terminals... IFR stratus has developed at MRY and 
persists through the morning. At SNS, confidence of stratus impacts 
has decreased and the prevailing stratus line has been converted to 
a TEMPO. Clearing is expected around 18Z as breezy northwest winds 
develop. Moderate confidence in an early return of stratus around 
00Z today, otherwise stratus is expected to return in the evening 
hours.

&&

.MARINE...
(Today through Wednesday)
Issued at 305 AM PST Fri Feb 13 2026

Hazardous conditions are expected through most of the forecast
period. Moderate to fresh northerly breezes will prevail through
the day before winds strengthen and back Saturday morning to
become strong and southerly. Rough seas will prevail for the inner
waters and outer waters into the next week. Rain returns Saturday
afternoon with wet conditions expected into next week.

&&

.BEACHES...
Issued at 945 PM PST Thu Feb 12 2026

Hazardous beach conditions are expected at Pacific Coast beaches,
excluding the northern Monterey Bay, through Saturday morning. A 
moderate to long period northwesterly swell will result in an 
increased risk of sneaker waves and strong rip currents with
breaking waves of 14 to 19 feet. Remember: 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!

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through late tonight for CAZ006-505-509-
     530.

PZ...Small Craft Advisory from 9 PM Saturday to 9 AM PST Sunday for 
     Mry Bay-Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 
     10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt 
     Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.

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

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

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

&&

$$

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

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Prepared by Boulder-Creek.com Weather at: Fri Feb 13 04:30:04 PST 2026
From the National Weather Service