FXUS66 KMTR 171800
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1000 AM PST Tue Feb 17 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 327 AM PST Tue Feb 17 2026
- Winter Weather Advisory Central Coast Mts and Santa Clara Hills
today through 4 PM Wednesday with accumulating snow
- Cold Weather Advisory North Bay and southern Salinas Valley
midnight tonight through 9 AM Wednesday morning
- Extreme Cold Warning Los Padres NF/Santa Lucia mtns and
interior Monterey and San Benito counties midnight tonight
through 9 AM Wednesday morning
- Rain and low snow levels continue this week as additional
storm systems arrive
- A Coastal Flood Advisory is in effect through 3 PM today for
minor high tide flooding
- Much colder late Thursday and Friday morning
&&
.UPDATE...
Issued at 918 AM PST Tue Feb 17 2026
A potent cold front is in the progress of sweeping through the
Bay Area. This front is bringing a wide variety of impactful
weather to start the day. Rain: enough moisture and lift has led
to moderate to locally heavy rain this morning. Enough fell to
result in minor flooding issues with ponding on roads and some
dirt/rock coming down some of the hill sides. Rainfall amounts
over the last 12 hours have generally ranged from a few hundredths
to near three quarters of an inch. Wind: winds increased ahead of
the front and remain gusty with the fropa. Wind gusts since
midnight have ranged generally from 15-30 mph most area and 40-60
mph over the higher peaks. Snow: the front is ushering in colder
air dropping snow levels to near 3k per profilers in the N Bay.
Cams and spotters indicate a few inches have fallen over the Mt
Saint Helena area and Cobb Mt. Mt Hamilton also reported a few
inches this morning. Thunderstorms: the dynamics with the fropa
and colder air aloft led to numerous lightning strikes around the
region. Lightning networks picked up roughly 500 total lightning
strikes in the region. Given the cold air aloft small hail (rice
to pea) has been reported.
As the front marches S and E expect similar conditions over the
Central Coast this afternoon.
No near term updates needed.
&&
.SHORT TERM...
Issued at 421 AM PST Tue Feb 17 2026
(Today and tonight)
Large, deep, cold troughing over the west coast isn't going
anywhere soon. West to northwest winds continue to transport
colder air into the Bay Area and the north Central Coast this
morning. The colder air is picking up sea surface heat -even with
cool sea surface temps in the mid to upper 50s that's milder
compared to air temperatures aloft. Onshore winds continue to
bring showers and cold air aloft continues to result in low snow
levels. Recent check of air temps at Mt St Helena, Mt Diablo, Mt
Umunhum, Mt Hamilton and Chews Ridge vary from 29F to 34F
supporting snow. Best chance of accumulating snow is the Santa
Clara Hills and across the north Central Coast mountains where a
Winter Weather Advisory is in effect through 4 pm Wednesday.
Low temperature forecasts warrant a Cold Weather Advisory for the
North SF Bay Area and the southern Salinas Valley midnight
tonight through 9 AM Wednesday morning. An Extreme Cold Warning
was issued for the Los Padres NF/Santa Lucia mtns and interior
Monterey and San Benito counties midnight tonight through 9 AM
Wednesday morning.
Light measurable precipitation and a continuation of onshore
winds are forecast tonight and Wednesday morning with a temporary
greater influx of maritime influence possible late tonight and
early Wednesday which may cause some upward fluctuations in
temperatures, but nonetheless cold conditions will be hazardous to
sensitive populations such as unhoused individuals, pets and
livestock. Cold conditions may damage or kill sensitive crops,
plants, and vegetation if appropriate precautions are not taken.
Prolonged exposure to the cold conditions will lead to hypothermia
for people, pets, and livestock.
&&
.LONG TERM...
Issued at 421 AM PST Tue Feb 17 2026
(Wednesday through Monday)
Currently it looks like the coldest weather this week will be from
late Thursday into Friday morning based on recent guidance. If
clearing takes place and there are light winds this combination is
more ideal to allow temperatures to lower due to nocturnal radiative
cooling. May need to issue additional cold weather advisories/extreme
cold warnings. This will also be the best chance for a dry break in
the weather. When the weekend arrives so too will be the potential
for additional rain and wind with another large cold pool of air
tapping Pacific moisture.
&&
.AVIATION...
(18Z TAFS)
Issued at 944 AM PST Tue Feb 17 2026
Heaviest of the rain bands moving thru Bay Area as of this 18Z
hour, featuring embedded heavier cells with some frqt ltg. Much
of this TSRA activity anticipated to decrease through the 21Z
hour. Rain rates reduce this afternoon and winds begin to shift
slightly more to westerly. Winds look to turn more NW in the
evening and into Tuesday night. Rain chances continue beyond the
TAF period with another round of widespread showers Wednesday
midday.
Vicinity of SFO...Heaviest of the rain bands moving thru Bay Area
as of this 18Z hour, featuring embedded heavier cells with some
frqt ltg. Much of this TSRA activity anticipated to decrease
through the 21Z hour. Expect stronger winds and gusts to linger
into early Tuesday afternoon with gusts above 30 kts. These winds
will reduce slightly into the evening as they turn more westerly
and then northwesterly into the night.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Stronger and gustier SW winds build this
afternoon as rain rates increase. Showers become more scattered
late Tuesday afternoon and into the evening while winds turn
westerly and reduce.
&&
.MARINE...
(Today through Sunday)
Issued at 944 AM PST Tue Feb 17 2026
Isolated moderate to heavy rainfall over the waters the morning.
Strong westerly winds are expected today with gale force gusts
expected late morning and into the afternoon. Winds slacken some
late Wednesday into early Thursday but quickly become strong again
with near gale to gale force gusts returning. Rough to very rough
seas will prevail through the week. Thunderstorm chances linger
into the mid week.
&&
.BEACHES...
Issued at 448 PM PST Mon Feb 16 2026
The combination of spring tides and storm surge are bringing
minor high tide flooding to the San Francisco Bay and Monterey Bay
through Tuesday. Up to 1.0 ft of inundation is expected in the
San Francisco Bay, with up to 1.5 ft in the Monterey Bay. At the
San Francisco tidal gauge, high tide is expected at 10:58 AM
Tuesday. High tide timing varies up to 90 minutes earlier or later
along the Pacific Coast and throughout the San Francisco Bay,
respectively.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 3 PM PST this afternoon for CAZ006-
506-508-529-530.
Cold Weather Advisory from midnight tonight to 9 AM PST
Wednesday for CAZ504-506-516.
Winter Weather Advisory until 4 PM PST Wednesday for CAZ514-517-
518.
Extreme Cold Warning from midnight tonight to 9 AM PST Wednesday
for CAZ517-518.
PZ...Small Craft Advisory until 3 AM PST Wednesday for Pt Arena to Pt
Reyes 10-60 NM-SF Bay N of Bay Bridge.
Gale Warning until 3 PM PST this afternoon 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 Reyes to Pigeon Pt 0-10 nm.
Gale Warning until 9 PM PST this evening for Pt Pinos to Pt
Piedras Blancas 0-10 nm.
&&
$$
SHORT TERM...Canepa
LONG TERM....Canepa
AVIATION...Behringer
MARINE...Behringer
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Prepared by Boulder-Creek.com Weather at: Tue Feb 17 12:30:03 PST 2026
From the National Weather Service
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