FXUS66 KMTR 191151
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
351 AM PST Thu Feb 19 2026
...New BEACHES...
.KEY MESSAGES...
Updated at 1256 AM PST Thu Feb 19 2026
- Thunderstorms capable of producing lightning, erratic/gusty
winds, locally heavy rainfall, accumulating small hail, and
waterspouts will be possible this morning with the cold frontal
passage
- Rain showers and thunderstorms will remain possible in the
post-frontal environment
- Accumulating snow is possible in the higher terrain, especially
for the Central Coast
- Cold to very cold conditions return tonight
- Hazardous beach conditions for Pacific Coast beaches through
Friday morning
&&
.SHORT TERM...
Issued at 1256 AM PST Thu Feb 19 2026
(Today and tonight)
A gale force low pressure system just outside of our marine zones
will continue to strengthen as it approaches the Pacific Coast. The
attendant cold front is expected to bring at least briefly hazardous
conditions in terms of thunderstorms and wind. The three ingredients
needed for a thunderstorm are lift, instability, and moisture.
Multiple lifting mechanisms are in place with upper-level support.
The instability can be characterized by conditionally unstable low-
level lapse rates and low CAPE. Today's 00Z sounding observed a PWAT
value of 0.52 inches (daily mean 0.59 inches) with the moisture
confined to the low and mid levels. While not necessary for
development, shear is another thing to look at for thunderstorms,
especially for severe potential. Forecast soundings have 30 knots of
0-1 km shear, 50 knots of 0-3 km shear, and 90 knots of 0-6 km
shear. This environment as a whole can be characterized as a high
shear, low CAPE environment: 500 J/kg or less of SBCAPE, 1000 J/kg
or less of MUCAPE, and 0-6 km shear of 35 knots or more. This
environment will be capable of producing thunderstorms with
lightning, locally strong to damaging gusts, accumulating small
hail, and waterspouts. Strong southerly winds will develop ahead
of the cold front and quickly veer after its passage to become
northwesterly. Gusts up to 50 mph are likely across the Pacific
Coast and in the higher terrain with 30-40 mph expected in low-
lying interior locations. If you must drive this morning:
keep your headlights on, keep your cruise control off, leave
plenty of following distance between the car in front of you, and
allow extra time to reach your destination. Post-frontal rain
showers are expected with a low potential for thunderstorms. Post-
frontal clearing will allow for widespread cold to very cold
conditions to settle in Thursday night. These conditions will be
impactful to people, pets, and plants - please take the necessary
precautions for each. Damp conditions will have it feeling colder
than the thermometer reads as well as pose the risk for black ice.
The warm front associated with the surface low is adding some
complexity to the snow forecast; nonetheless, high elevation snow
remains possible, especially for the Central Coast where
accumulation up to 10 inches is possible.
&&
.LONG TERM...
Issued at 1256 AM PST Thu Feb 19 2026
(Friday through Wednesday)
Friday will be cold and dry with temperatures well below normal.
Rain returns Saturday as a rapidly intensifying storm force low
pressure system encroaches the West Coast. Fortunately, it looks to
stay in the Pacific Northwest which will keep our region merely on
the periphery of it. Still, an increase in rainfall coverage and
intensity and wind can be expected. The parent low in the Gulf of
Alaska will persist, allowing for the entrainment of tropical
moisture in the Sunday into Monday timeframe. Minor flooding in low-
lying, poor drainage, and urban areas should be expected as a
result. There's a low probability (20% chance or less) of mainstem
river flooding; however, if the QPF forecast trends higher and/or
the heaviest rainfall sets up over a watershed, probabilities will
increase.
&&
.AVIATION...
(12Z TAFS)
Issued at 341 AM PST Thu Feb 19 2026
The 500 mb trough is quickly moving eastward, the surface low and
cold front will also move eastward across the Bay Area this morning.
MVFR-IFR in moderate to heavy rain becoming showery during the day
with gusty northwest winds. Clearing /VFR/ tonight and Friday
morning.
Vicinity of SFO...Winds ahead of the cold front became gusty back
at 11z with gusts to 35 knots. Post cold frontal winds will shift
to the west and likely become gusty again near 35 knots during the
morning and afternoon. Heavy rain tapering off to showers through
later morning and afternoon. Clearing tonight and Friday morning.
MVFR through morning then VFR this afternoon, tonight and Friday
morning.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Southeasterly winds increasing ahead of a
surface cold front early this morning, winds then shifting to W-NW
by mid to late morning. Heavy rain tapering off to showers by late
morning and afternoon. MVFR through morning then VFR this afternoon,
tonight and Friday morning.
&&
.MARINE...
(Today through Tuesday)
Issued at 341 AM PST Thu Feb 19 2026
Northwest winds strengthening through today with widespread gale
force gusts. Winds ease tonight into Friday as high pressure
builds in from the northwest. Rough to very rough seas prevail
through the week. Rain chances return Saturday afternoon into late
weekend.
&&
.BEACHES...
Issued at 351 AM PST Thu Feb 19 2026
A High Surf Advisory remains in effect from the coastal North Bay
to coastal Monterey County until 9 AM Friday. Dangerous conditions
with localized beach erosion can be expected. Sneaker waves can
sweep across the shoreline without warning, pulling people into
the sea from rocks, jetties and beaches. Large breaking waves can
overpower swimmers resulting in significant physical injury and
increase the risk of drowning.
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. Monitor local weather, surf
and tide forecasts at www.weather.gov/mtr.
&&
.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.
Cold Weather Advisory from 1 AM to 9 AM PST Friday for CAZ502-
503-505-508-512-513-528-529.
Extreme Cold Warning from 1 AM to 9 AM PST Friday for CAZ504-506-
510-514>518.
Winter Weather Advisory until 7 AM PST Friday for CAZ517-518.
PZ...Gale Warning until 9 PM PST this evening 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.
&&
$$
SHORT TERM...Sarment
LONG TERM....Sarment
AVIATION...Canepa
MARINE...Canepa
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Prepared by Boulder-Creek.com Weather at: Thu Feb 19 04:30:03 PST 2026
From the National Weather Service
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