FXUS66 KMTR 211902
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1202 PM PDT Sat Mar 21 2026
...New AVIATION...
.KEY MESSAGES...
Updated at 301 AM PDT Sat Mar 21 2026
- Much cooler, but still above average temperatures today
- Continued cooling for Sunday
- Dry weather at least through the end of the month
&&
.UPDATE...
Issued at 855 AM PDT Sat Mar 21 2026
High clouds cover the region as a weak cold front passes through
the region, with low-level stratus having mostly cleared out at
the immediate coast. The current forecast remains on track with
temperatures near to slightly above seasonal averages today. For
more information, refer to the previous discussion.
DialH
&&
.SHORT TERM...
Issued at 301 AM PDT Sat Mar 21 2026
(Today and tonight)
The transition from ridging and high pressure to a modest zonal flow
is already affecting temperatures. A map of 24 hour temperature
change shows most areas around 5 degrees cooler than this time last
night, with portions of the Big Sur Coast around 20 degrees cooler
as the thermal belt erodes.
The marine layer is also redeveloping, leading to some pockets of
coastal fog and stratus along the coast of Monterey Co and around
Half Moon Bay. The reducing pressure will allow the marine layer to
expand through the morning, and hints at a weak southerly surge of
stratus along the Big Sur. Areas affected by this push of stratus
look to have much cooler temperatures than previous days, but this
will be focused on the immediate coast.
The rest of the region will still see a notable cooldown today as
the pressure reduces and slight onshore flow develops. Highs will
range 5 to 15 degrees cooler than previous days, with the low 60s on
the coast, 70s for areas slightly more inland, and the 80s for the
more interior areas. This will still be roughly 5 to 10 degrees
above average for the non-coastal areas, but will be a welcome
change of pace from the hazardous, record-breaking heat of the work
week.
&&
.LONG TERM...
Issued at 301 AM PDT Sat Mar 21 2026
(Sunday through Friday)
The cooling trend continues into Sunday with highs and lows reducing
by a few more degrees. But this is where our pattern looks to hold
steady. Our zonal to slight ridging pattern continues through the
next work week, keeping highs and lows fairly similar from day to
day. Some spots in the Bay Area will see only a 3 degree difference
from the warmest day to the coolest day.
Chances for coastal drizzle have fizzled out as Wednesday's cold
front has pushed farther north in more recent model update. With
those chances out of the forecast, it looks like it might not be
until the very end of the month before chances for rain return to
the forecast. Some of the extended term models still show a
developing trough pushing a weak low pressure into the Bay Area into
April. But even the most optimistic models only show chances for
scattered light rains as this low weakens as it approaches.
&&
.AVIATION...
(18Z TAFS)
Issued at 1032 AM PDT Sat Mar 21 2026
VFR with high clouds streaming overhead. VFR most locations
through the TAF period. Will be watching a low chc (less than 20%)
for fog at KSTS. Some coastal stratus will develop late tonight
and early Sunday with impacts most likely for KHAF and KMRY.
Vicinity of SFO...VFR. Onshore flow ramps up this afternoon with
gusts 20-25kt. Winds ease overnight.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR. 60-80% chc for cigs returning to
KMRY after 08Z and then in TAF by 11Z. Impacts less at KSNS.
&&
.MARINE...
(Today through Thursday)
Issued at 855 AM PDT Sat Mar 21 2026
A passing cold front will bring fresh and strong breezes with gale
force gusts to the coastal water today. Strongest winds will be
over the outer waters and in the Point Reyes coastal jet region.
The strong winds will lead to steep fresh swell. Winds diminish
and seas abate early next week then increase again mid week.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Gale Warning until 3 AM PDT Sunday for Pigeon Pt to Pt Pinos 10-
60 NM-Pt Arena to Pt Reyes 0-10 nm.
Small Craft Advisory until 3 AM PDT Sunday for Pigeon Pt to Pt
Pinos 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt
Reyes to Pigeon Pt 0-10 nm.
Gale Warning until 9 AM PDT Sunday for Pt Arena to Pt Reyes 10-
60 NM.
&&
$$
SHORT TERM...Murdock
LONG TERM....Murdock
AVIATION...MM
MARINE...MM
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: Sat Mar 21 12:30:02 PDT 2026
From the National Weather Service
|