FXUS66 KMTR 021142
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
332 AM PST Fri Jan 2 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1236 AM PST Fri Jan 2 2026
- High astronomical tides combined with storm surge will bring
substantial tidal flooding through Sunday
- Strong southerly winds Friday night into Saturday morning
- Chance of thunderstorms Friday night through the weekend
- Daily rain showers expected through Monday
&&
.SHORT TERM...
Issued at 1236 AM PST Fri Jan 2 2026
(Today and tonight)
There's a few scattered showers on radar, but we're mostly
enjoying a break before the next round of heavy rain and strong
wind arrives tonight. Southerly winds are starting to show up
along the coast and in properly oriented valleys. Salinas and Half
Moon Bay are both reporting a moderate southerly breeze with
gusts up to 20 knots. The IR satellite image shows what we're up
against later today. A mature low pressure system in the Eastern
Pacific around 40N137W is supporting a very long cold-type
occluded front. As this front approaches the coast overnight, the
rain intensity and wind strength will both increase. Winds will
steadily increase through the day, peaking around midnight.
Sustained winds of 15-25 mph are expected, with occasional gusts
to 50 mph along the coast and in higher terrain. That's a little
weaker than last week's storms, but still enough to cause tree
damage and possible power outages. On average we're expecting
about 1/2" of rain overnight, with up to 3" in the coastal
mountains and closer to 1/4" in the rain shadowed valleys.
&&
.LONG TERM...
Issued at 1236 AM PST Fri Jan 2 2026
(Saturday through Thursday)
After the front passes Saturday morning, the precipitation mode
will switch from stratiform rain to convective showers. Some of
these showers will be strong, and there is a decent chance for
thunderstorms throughout the day Saturday as a few post frontal
short wave troughs move through. The 06Z HRRR shows one of these
pulses will line up well with the warmer, more unstable conditions
in the afternoon. There is a marginal chance for severe
thunderstorms in the North and East Bay, with tornadoes as the
most likely severe threat in the typical low CAPE, high shear
environment. High resolution model point soundings in the North
Bay show around 100 J/kg of CAPE, with 40-50 kts of 0-1km shear,
low LCL heights, and a nicely curved low level hodograph Saturday
afternoon. The severe threat is focused on the North Bay, but not
confined there. Landfalling waterspouts are possible along the
coast.
Reinforcing wet cold fronts will move through Sunday and Monday,
with a much drier FROPA midweek. This parade of cold fronts will
drop the 1000-500 mb thickness from 5,530 m today to 5,340 m by
Friday, bringing snow levels to around 3,000 feet. If we can get
any moisture late next week we'd have a real chance for some snow
flakes in the higher peaks around the Bay Area and Central Coast.
Otherwise we'll see temperatures drop back into the 30s for
inland areas towards the end of next week as a drier, more stable
pattern moves in.
&&
.AVIATION...
(12Z TAFS)
Issued at 332 AM PST Fri Jan 2 2026
VFR-MVFR with areas of light showers this morning. MVFR-IFR
tonight and Saturday with increasing rain and southerly winds.
Winds becoming strong and gusty tonight and Saturday morning, with
low level wind shear possible though not currently indicated in the
12z TAFs since it is likely that there'll be surface to lower level
mixing of winds.
Vicinity of SFO...VFR-MVFR. Off and on wet weather today, then
steady wet weather later today, tonight and Saturday. Increasingly
gusty southerly winds developing later today, tonight and Saturday
morning. Wind gusts to 35-40 knots tonight and early Saturday.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR-MVFR. Off and on wet weather today,
then steady wet weather tonight and Saturday. Increasingly gusty
southerly to southeasterly winds developing today, tonight and
Saturday morning.
&&
.MARINE...
(Today through Wednesday)
Issued at 322 AM PST Fri Jan 2 2026
Gales will develop over the coastal waters today and continue
tonight. Gales will continue over the northern outer waters
Saturday while winds decrease elsewhere. Expect wet, unsettled
weather and rough seas with a slight chance of thunderstorms over
the weekend. Wet and chilly weather continues early next week.
&&
.BEACHES...
Issued at 1236 AM PST Fri Jan 2 2026
A Coastal Flood Warning is in effect for the San Francisco Bay
through Saturday. A Coastal Flood Advisory is in effect for the
Pacific Coast and Monterey Bay through Sunday. Perigean spring
tides (king tides) will impact the region through Sunday. This is
due to the combination of the full moon on 1/3, lunar perigee on
1/1, and perihelion on 1/3. In other words the earth, sun and moon
are lined up and close to each other. In addition to the high
astronomical tide, the incoming low pressure system will bring
strong southerly winds, generating some storm surge, particularly
on Saturday morning. The combination of these factors will bring
moderate coastal flooding to the low-lying areas near shorelines
and tidal waterways during high tide through Sunday.
On Thursday, the San Francisco tidal gauge recorded 2.1 ft of
inundation. Looking ahead, high tide is expected to be 2.2 ft
above normal at 9:34 AM Friday, 2.5 ft above normal at 10:26 AM
Saturday, and 1.9 ft above normal at 11:18 AM Sunday. These
predictions include up to 1.3 feet of storm surge that will
enhance the astronomical tide and flooding threat. A reasonable
worse case scenario (10% exceedance chance) is 2.7 ft of
inundation on Saturday. The all time record is 2.8 ft from
1/27/1983. 2.5 ft hasn't been reached since 1998. High tide
varies up to 90 minutes earlier or later along the Pacific Coast
and through the San Francisco Bay, respectively.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 7 AM PST this morning for CAZ006-
506-508.
Coastal Flood Advisory from 2 PM Saturday to 2 PM PST Sunday for
CAZ006-506-508.
Coastal Flood Warning from 7 AM this morning to 2 PM PST
Saturday for CAZ006-506-508.
Wind Advisory from 1 PM this afternoon to 1 PM PST Saturday for
CAZ006-502>505-509-512-515>518-528>530.
Coastal Flood Advisory until 2 PM PST Sunday for CAZ505-509-529-
530.
PZ...Small Craft Advisory from 3 PM this afternoon to 3 AM PST
Saturday for SF Bay N of Bay Bridge.
Small Craft Advisory until 9 PM PST this evening for Mry Bay.
Gale Warning from 9 PM this evening to 3 AM PST Saturday for Mry
Bay.
Small Craft Advisory until 9 AM PST this morning 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 Reyes to Pigeon Pt 0-10 nm.
Gale Warning from 9 AM this morning to 3 AM 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 Reyes to Pigeon Pt 0-10
nm.
Gale Warning until 9 AM PST Saturday for Pt Pinos to Pt Piedras
Blancas 0-10 nm.
Gale Warning until 3 PM PST Saturday for Pt Arena to Pt Reyes 10-
60 NM.
&&
$$
SHORT TERM...Flynn
LONG TERM....Flynn
AVIATION...Canepa
MARINE...Canepa
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Prepared by Boulder-Creek.com Weather at: Fri Jan 2 06:30:02 PST 2026
From the National Weather Service
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