FXUS66 KMTR 201800
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1000 AM PST Fri Feb 20 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 303 AM PST Fri Feb 20 2026
- Cold to very cold conditions during the overnight period Friday
night into Saturday morning
- Unsettled weather with periods of rain and wind through the
long term forecast period
&&
.SHORT TERM...
Issued at 303 AM PST Fri Feb 20 2026
(Today and tonight)
Isolated rain showers continue across the marine zones and Central
Coast with the help of surface troughing. These rain showers will be
unimpactful and are expected to wane by sunrise. It is going to be a
cold start to the morning, so be sure to grab some extra layers on
your way out the door! The 00Z sounding observed an 850 millibar
temperature of -1.75 degrees Celsius which is below the tenth
percentile (-0.5 degrees Celsius) for the date and time. While it is
going to be cold, we are not expecting any records to be tied or
broken. Probably of more interest (and relief) in the short term is
that it is going to be dry as high pressure noses in from the
Eastern Pacific Ocean. Maximum temperatures will warm to 10 degrees
below normal today with another cold night on tap. Precautions
should be taken to protect people, pets, and plants.
&&
.LONG TERM...
Issued at 303 AM PST Fri Feb 20 2026
(Saturday through Thursday)
Unsettled weather will return this weekend as the region gets
skirted by a couple passing low pressure systems in the Pacific
Northwest. Light rain showers will return to the North Bay Saturday
morning with drizzle possible for locations farther south. More
impactful will be the wind with southerly gusts up to 45 mph
possible along the coast and in the higher terrain. Probabilities
are low to moderate (less than 50% chance) and are across a small
area, thus a Wind Advisory is not warranted at this time. The
weekend will be your best bet to clean up any damage that occurred
this week and prepare for next week's weather. Global ensemble
clusters are in agreement of upper-level ridging across the
Intermountain West and upper-level troughing off the Pacific
Northwest Coast with heights rising at least through Monday. Another
developing surface low pressure system off the Pacific Northwest
will source moisture from the tropics with ECMWF and GEFS IVT
ensemble mean peaking near 500 kg/ms by Tuesday. Southwesterly flow
(from the tropics) will allow for efficient rainfall due to the
fetch of moist, warm air. As a result, southwest facing terrain will
have the highest accumulation with the help of orographic lift with
the lee side valleys experiencing the rain shadow effect.
Fortunately, the trend has been our friend with all of the above
systems trending farther north between forecasts which will allow
for a reprieve between the deluge that we have experienced the past
week. As the forecast looks right now, the Monday into Tuesday
system will bring widespread rainfall. Minor flooding of low-lying,
poor drainage, and urban areas will be possible with ponding and
slick roadways a guarantee. Mainstem river flooding is not expected
with a low probability (less than 20%) of occurrence.
&&
.AVIATION...
(18Z TAFS)
Issued at 958 AM PST Fri Feb 20 2026
High confidence for VFR conditions to prevail through the TAF
period. Passing high clouds will persist through 00Z Saturday with
them returning by around 09Z Saturday. Lower cloud cover (still VFR)
is forecast to return late in the night across the North Bay and
then spread southward throughout the day on Saturday.
Vicinity of SFO...VFR. Weak offshore flow will prevail this
morning with northwesterly flow possible at times early this
afternoon. However, wind speeds are forecast to be generally less
than 6kt. Southerly winds are forecast to increase after 18Z
Saturday ahead of an approaching system.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR. North to northwesterly winds are
forecast to develop early this afternoon and prevail through
around sunset. Light and variable winds are forecast until
becoming southerly around 03Z Saturday and increasing into
Saturday morning ahead of an approaching system.
&&
.MARINE...
(Today through Wednesday)
Issued at 958 AM PST Fri Feb 20 2026
Winds will shift to southerly and increase over the weekend, the
strongest winds across the northern waters with gale force gusts
by Saturday afternoon. As a result, rough to very rough seas
redevelop by late weekend into early next week. Rain chances
return late Saturday and continue into early to mid next week.
&&
.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
San Rafael 32 in 2018, 2006
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...None.
PZ...Small Craft Advisory from 3 PM to 9 PM PST Saturday for Mry Bay.
Small Craft Advisory from 3 AM to 3 PM PST Saturday for Pt Arena
to Pt Reyes 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.
Gale Warning from 3 PM to 9 PM PST Saturday 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 Pinos to Pt Piedras Blancas 0-10 nm-Pt
Reyes to Pigeon Pt 0-10 nm.
Small Craft Advisory from 9 AM to 3 PM PST Saturday for Pigeon
Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt
Pinos to Pt Piedras Blancas 0-10 nm.
Small Craft Advisory from 9 PM this evening to 3 AM PST Saturday
for Pt Arena to Pt Reyes 10-60 NM.
Gale Warning from 3 AM to 9 PM PST Saturday for Pt Arena to Pt
Reyes 10-60 NM.
&&
$$
SHORT TERM...Sarment
LONG TERM....Sarment
AVIATION...RGass
MARINE...RGass
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 20 14:30:03 PST 2026
From the National Weather Service
|