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
Visit us at www.weather.gov/sanfrancisco
Follow us on Facebook, X, and YouTube at:
www.facebook.com/nwsbayarea
x.com/nwsbayarea
www.youtube.com/nwsbayarea
Prepared by Boulder-Creek.com Weather at: Fri Feb 13 04:30:04 PST 2026
From the National Weather Service
|