FXUS66 KMTR 190455
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
855 PM PST Wed Feb 18 2026
...New UPDATE, MARINE...
.KEY MESSAGES...
Updated at 422 PM PST Wed Feb 18 2026
- High elevation snow continues early Thursday morning with the
highest snow accumulations over the Central Coast
- Strong, gusty winds, moderate to heavy rain, and slight
potential for thunderstorms expected around the time of frontal
passage early Thursday morning
- Below February normal cold continues with overnight lows and
damp conditions making it feel even colder impacting people
without adequate shelter
- Near record breaking cold temperatures Thursday night into
Friday morning
- Active weather continues with additional chances for rain into
next week
&&
.UPDATE...
Issued at 837 PM PST Wed Feb 18 2026
No real notable change in the near term forecast. KMUX radar
imagery remains active this evening. Cold and unstable atmosphere
remains over the region leading to scattered showers across the
region. KOAK sounding showed weak instability and lower freezing
levels near 3700 feet. As such, the showers are more convective,
but not seeing any lightning observed. However, we've had reports
of heavy rain and small hail. ADditionally, the low freezing
level is resulting in some snow falling across the higher peaks.
Since the afternoon update another Winter Weather Adv was issued
for the Central Coast. Forecasting snow across the higher peaks
of the Central Coast is very nuanced and a few hundred feet of
snow level drift can make all the difference. Updated the snow
amounts downward to adjust for the snow level drift. Thinking
that the higher snow ration (10:1 or higher on some guidance) is
overdone. The next system, currently upstream, will make its way
southward tonight. The jet max up north will phase with a jet near
the Central Coast created a rather dynamic setup. See details
below. As this happens, there appears to be a warm nose with snow
levels drift upward for a few hours then dropping back down. That
will definitely eat some snow totals. Regardless, a few inches
will be possible above 4000-4500 ft and just fits in Advisory
criteria. Additionally, the snow will fall with some robust winds
with blizzard like conditions.
No other updates this evening.
MM
&&
.SHORT TERM...
Issued at 422 PM PST Wed Feb 18 2026
(This evening through Friday)
Scattered showers continue through this evening across the region
before the next storm system arrives tonight. Widespread moderate to
heavy rain will return tonight as our third system approaches. Rain
intensity will pick up overnight with the heaviest precipitation
expected between 3AM to 7AM Thursday morning. Frontal passage will
occur between 4AM to 10AM (likely closer to 4AM-6AM period) with
high resolution guidance showing a squall line moving through the
Southern San Mateo Peninsula into the South Bay and Central Coast.
This is supported by a strong 925 mb low level jet with a jet max
near 70 knots (80 mph) moving into the Monterey Bay. This jet max is
consistent across several high resolution models (NAM, RRFS, HRRR)
and would support strong but short-lived gusts directly along the
coastline. Highest confidence in widespread gusts between 30 to 40
mph with locally stronger gusts between 45 to 50 mph directly along
the coastline and across the higher elevations possible. Portions of
the Big Sur Coastline and where terrain promotes wind funneling (low
probability Salinas Valley, Golden Gate Gap) may see gusts in excess
of 50 mph. Short-lived gusts in excess of 50 mph are likely as the
squall line moves through with winds to drop after frontal passage
occurs. Forecast soundings show low level 0-1 km wind shear between
20 to 25 knots and 0-3 km wind shear in excess of 40 knots
(particularly along the Big Sur Coast). High resolution guidance
shows decent MUCAPE (100-450 J/KG) in the marine environment
offshore of Santa Cruz down through Monterey County. The combination
of strong low level shear and decent MUCAPE will result in a High
Shear Low CAPE setup early tomorrow morning. Embedded rotation is
possible within the squall line, particularly offshore over the
marine environment, with the potential to impact coastal areas as
the squall line moves ashore. Currently the SPC has a general
mention of thunderstorms in effect for Thursday across our entire
CWA. In addition, accumulating small hail is possible as the squall
line moves through due to the cold airmass (850mb temperatures are
below freezing across much of the CWA around the time of frontal
passage). There is the potential for locally heavy downpours as the
squall line moves onshore which may result in flooding particularly
within coastal areas. Early morning commuters on the Central Coast
be aware - this system will arrive around the time of the morning
commute. Check the weather before you leave, allow extra time to
reach your destination, and go slow. It would be advisable to avoid
driving as this squall line moves ashore.
Rain chances and wind speeds diminish by late morning after frontal
passage occurs. Widespread showers will become more scattered in
nature (similar to today) by late morning/afternoon. High
temperatures will not be particularly warm on Thursday with most
locations staying in the upper 40s to low 50s. Across the higher
elevations temperatures may not get out of the upper 30s to low 40s.
As cloud cover dissipates late Thursday, overnight temperatures
Thursday into Friday will drop rapidly into the upper 20s to low 30s
across the region. A combination of Cold Weather Advisories and
Extreme Cold Warnings will be needed Friday morning.
&&
.LONG TERM...
Issued at 422 PM PST Wed Feb 18 2026
(Friday night through next Wednesday)
Conditions briefly dry out on Friday as we get a break between
systems but this will be short lived as another upper level trough
and system arrives Saturday into Sunday. High temperatures on Friday
will still be chilly in the low to mid 50s but if you need to make
any outdoor preparations before the rain returns this is your
chance. Rain returns Saturday with light rain spreading across the
region during the afternoon/evening. Saturday night into Sunday will
see the return of widespread moderate to at times heavy rain. The
heaviest rain is expected Sunday and Monday as a possible
atmospheric river develops. While the previous system (this week)
originated from the Gulf of Alaska, this upcoming system has a more
tropical moisture source with PWAT values in excess of an inch.
While the heaviest rain is Sunday and Monday, light to at times
moderate rain will continue through the rest of the week. From
Saturday to next Wednesday - we are looking at an additional 4-6"
across the North Bay Mountains, 3-5" across the Santa Cruz Mountains
and Santa Lucia Range, and 1-3" across the lower elevations. A
return of strong winds is expected late Saturday night into early
next week. Temperatures will warm next week with highs in the upper
50s to low 60s across the region starting Monday. Morning low
temperatures rise into the upper 40s to 50s by Monday morning. This
is an active period of weather. Make sure you have multiple ways to
receive warnings this week and stay up to date on the weather
&&
.AVIATION...
(00Z TAFS)
Issued at 521 PM PST Wed Feb 18 2026
Spotty light to moderate showers are moving through the area, but
shower activity is expected to reduce into the night. Mostly mid-
level clouds are moving through the area, but these showers could
offer short-lived MVFR CIGs. Winds stay westerly for most of the
region into the evening but some areas look to turn more northerly
overnight as winds reduce. Shower activity increases into Thursday
morning with widespread rain and stronger winds arriving along a
front. Gusts will approach 30 kts and above for most areas along the
front and rain rates will reduce visibilities. Expect winds to turn
westerly to northwesterly in the wake of the front. Storm chances
will build in the post frontal environment and last into the
afternoon. Rain chances reduce that evening, but showers linger into
that night.
Vicinity of SFO...Shower activity continues with mostly mid-level
clouds. Winds turn southwest overnight and reduce, but become
southeasterly and breezy later into the night. The next band of
moderate to heavy rain arrives int he late night bringing strong
gusts above 30 kts form the southeast that will turn westerly as the
band moves through. Shower activity reduces behind the rain band,
but thunderstorms will be possible. Winds remain strong into the
afternoon but will reduce as showers become more scattered.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Spotty showers last through the night with
moderate winds turning southerly. The next rain band arrives into
the late night and early morning with stronger winds building ahead
of it. Gusts will peak above 30 kts and rain rates will reduce
visibilities. Winds reduce slightly behind the rain band, but shower
activity will continue through the afternoon. Chances for storms
will increase behind the rain band, especially in the bay itself and
along the Big Sur coast.
&&
.MARINE...
(Tonight through next Tuesday)
Issued at 837 PM PST Wed Feb 18 2026
Expect light showers to move through the waters with moderate to
breezy winds through the night. Winds quickly become strong in
the late night with widespread gale force gusts returning as
moderate to heavy rains move through the waters. Chances for
thunderstorms increase through the early morning on Thursday, but
these chances reduce that afternoon. Rough to very rough seas will
prevail through the week. Rain chances in general exit early
Friday, but the next system begins to arrive Saturday afternoon.
&&
.CLIMATE...
Issued at 1047 PM PST Tue Feb 17 2026
The following are the record low temperatures at the long term sites
for Friday, Feb 20th.
Location Record Low
Santa Rosa 26 in 1913
Kentfield 27 in 1913
Napa 27 in 2018
Richmond 35 in 1990
Livermore 27 in 2018
San Francisco 38 in 1897
SFO Airport 36 in 2018
Redwood City 30 in 1933
Half Moon Bay 28 in 2018
Oakland Museum 36 in 2011
San Jose 30 in 1897
Salinas Airport 28 in 1953
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory until 9 AM PST Friday for CAZ006-505-509-529-
530.
Winter Weather Advisory from midnight tonight to 7 AM PST Friday
for CAZ517-518.
PZ...Gale Warning from 3 AM to 9 PM PST Thursday 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 Arena to Pt Reyes 10-60 NM-Pt
Pinos to Pt Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-
10 nm-SF Bay N of Bay Bridge.
Small Craft Advisory until 3 AM PST Thursday for Mry Bay.
Small Craft Advisory until 3 AM PST Thursday for 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 Arena to Pt Reyes 10-60 NM-Pt Pinos to Pt
Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.
&&
$$
SHORT TERM...Kennedy
LONG TERM....Kennedy
AVIATION...Murdock
MARINE...Murdock
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Prepared by Boulder-Creek.com Weather at: Wed Feb 18 22:30:03 PST 2026
From the National Weather Service
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