FXUS66 KMTR 261644 AAB
AFDMTR
Area Forecast Discussion...UPDATED
National Weather Service San Francisco CA
944 AM PDT Sun Jul 26 2026
...New UPDATE, MARINE...
.KEY MESSAGES...
Updated at 505 AM PDT Sun Jul 26 2026
- Breezy onshore winds expected each afternoon and evening
through early in the week
- Gradual warming starting midweek, with increasing Moderate
HeatRisk for interior locations heading into the weekend
- Elevated fire weather threat across the Diablo and Santa Lucia
Ranges this week
&&
.UPDATE...
Issued at 943 AM PDT Sun Jul 26 2026
Minor updates to the forecast package this morning with the main
emphasis on temperatures, as well as heat and fire weather
messaging. Despite 24 hour temperature differences running 2-5
degrees lower than this time yesterday, the relatively dry airmass
should promote a sharp diurnal temperature curve mainly away from
the coast. Highs across the interior should climb into the 90s
with a few locales topping the century mark, especially across the
interior Central Coast and this has been reflected in the latest
update.
Elevated breezes, especially across some of the favored gaps and
passes, will approach the 30 to 40 mph range. Despite the flow
being onshore, the shallow marine layer may not provide much of a
boost to the afternoon humidity across these interior regions.
Fuels continue to cure and as a result, there will be an elevated
fire weather threat today and potentially through mid-week for the
interior North Bay, East Bay, and Central Coast. Additionally,
overnight RH recovery through Wednesday morning may only range
between 25 and 50% above 2500' elevation across the North Bay
Mountains, Santa Lucia, and Diablo Ranges. Be sure to avoid
activities that could spark a fire, especially across the interior
Central Coast, where vegetation dryness is the greatest. We'll
continue to examine the potential for above normal temperatures
later this week as a ridge over the Pacific Southwest attempts to
build westward. It certainly appears that locations across the
East Bay and Central Coast interior will have the opportunity for
impactful heat as early as Thursday.
&&
.SHORT TERM...
Issued at 1232 AM PDT Sun Jul 26 2026
(Today and tonight)
Upper level troughing holds over the eastern Pacific and into the
PacNW today, slowly meandering eastward. Satellite trends show
stratus forming along portions of the northern California coast,
which should bring stratus to most coastal locations and down into
the Monterey Bay. Uncertainty remains on how deep the marine layer
gets tonight, though current thinking is it'll be between 500-
1000ft. Any stratus that forms tonight should retreat to the coast
by mid to late morning with mainly sunny skies prevailing.
&&
.LONG TERM...
Issued at 1232 AM PDT Sun Jul 26 2026
(Monday through Saturday)
We will remain under an elongated trough through early to midweek,
leading to typical summer like days. Look for seasonal temperatures,
breezy onshore winds each afternoon and evening, and the return of
stratus. The marine layer should get to about 1000ft for the next
few nights, with it a 500-1000ft marine layer by midweek for those
along the coast. This is when we start to see high pressure over the
Desert Soutwest build into southern and central California and begin
pushing the trough and making it a bit more compact. Onshore flow
should help moderate temperatures near the coast, as we go from a
trough to quasi-zonal flow. Warmer temperatures will be expected
inland, but overall temperatures will continue to increase as we
head into the weekend. Widespread Moderate HeatRisk continues to
look likely for interior locations.
&&
.AVIATION...
(12Z TAFS)
Issued at 535 AM PDT Sun Jul 26 2026
Marine stratus is more organized than the past couple of nights.
Our presently ascending weather balloon indicates that marine
layer depth is around 1200-1500 feet, allowing for an influx of
stratus as far east as the LVK. Area webcams do indicate that this
deck of MVFR to IFR ceilings is thin and as such I anticipate that
after sunrise, clouds will erode. Visibility reductions are
anticipated to be limited to STS where river valley fog has
arrived and occasionally at HAF. By mid to late morning, VFR is
anticipated to return to most terminals, except HAF. VFR is
advertised here after 21Z with low to medium confidence. Monday
morning should feature a slightly stronger onshore push. Model
performance over the last few days does lower confidence in the
stratus forecast and if afternoon satellite trends are similar to
the past few days, alterations may be needed.
Vicinity of SFO...Intermittent IFR and MVFR anticipated to persist
through the morning push, but high confidence in VFR by 18Z.
Onshore flow through the San Bruno Gap coupled with a slightly
compressed marine layer will support wind gusts to near 30 knots.
There is an outside chance that gusts over 35 knots could
transpire. By sunrise Monday, stratus is anticipated to return as
onshore flow is expected to increase slightly (tighter SFO-SAC/SMX
gradient), though confidence is low in the onset time. Model
guidance offers a broad range with the earliest time around 05Z.
Overall, the model consensus is closer to 09Z and this timing
would be earlier than the previous nights, lending a bit of
confidence in this being a reasonable scenario. With the stronger
onshore push, MVFR is advertised through the extended portion of
the TAF, but additional refinements are probable.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Stratus has been slow to materialize this
morning, but latest satellite imagery indicates a building deck of
clouds along the bay. IFR, with intermittent VFR should be
anticipated, especially at MRY through late morning. At SNS, IFR
is expected to be more intermittent in nature and should arrive
with the next hour. Tonight, a more typical stratus pattern should
set up with MVFR/IFR returning between 02-04Z with IFR at MRY. IFR
is a little less certain at SNS, so for now MVFR is forecast.
&&
.MARINE...
(Today through Friday)
Issued at 914 AM PDT Sun Jul 26 2026
Fresh northwest breezes gradually increase to strong by Tuesday
with occasional gale force gusts. However, frequent gale force
gusts are expected along Big Sur. In response, moderate seas
gradually build to rough by Wednesday. Distant tropical cyclone
activity in the East Pacific continues to send long period
southerly swells to our coastal waters.
&&
.BEACHES...
Issued at 911 AM PDT Sat Jul 25 2026
Tropical cyclones in the Eastern Pacific are generating a long-
period southwesterly swell which has reached the coastline of the
San Francisco Bay Area and Central Coast. As such, sneaker waves and
strong rip currents are the primary concerns. However, breaking
waves can reach up to 10 feet along some south and southwest facing
beaches and break points (like Santa Cruz, Pacifica, and parts of
Stinson or Ocean Beach). Sneaker waves can have 20+ minutes in
between the larger sets (breaking waves) with significant "flat/calm
looking" times between them. This can potentially catch beachgoers
by surprise and resulting in people being swept into the cold
turbulent ocean; hence the name "sneaker". Rip currents are
strong enough to pull the strongest swimmers away from shore. Swim
near a lifeguard if possible. Stay back from the beach, and away
from jetties, piers, beachside rocks, and other infrastructure
near the water. Never turn your back to the ocean! The Beach
Hazards Statement has been extended through Wednesday afternoon
for all beaches along the Pacific Coast.
RGass
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Wednesday afternoon for CAZ006-
505-509-529-530.
PZ...Small Craft Advisory until 9 PM PDT this evening for Mry Bay.
Small Craft Advisory from 9 AM to 3 PM PDT Monday for Mry Bay.
Small Craft Advisory until 3 PM PDT Monday 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.
Small Craft Advisory from 3 PM this afternoon to 3 PM PDT Monday
for Pt Arena to Pt Reyes 10-60 NM-Pt Reyes to Pigeon Pt 0-
10 nm.
Gale Warning until 3 AM PDT Monday for Pt Pinos to Pt Piedras
Blancas 0-10 nm.
&&
$$
UPDATE...Bain
SHORT TERM...KR
LONG TERM....KR
AVIATION...Bain
MARINE...Navarrete
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: Sun Jul 26 10:30:03 PDT 2026
From the National Weather Service
|