FXUS66 KMTR 011128
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
428 AM PDT Sat Aug 1 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 1251 PM PDT Fri Jul 31 2026

 - Gradual warming trend through the weekend with Moderate 
   HeatRisk in the interior through the early part of next week

 - Elevated fire weather threat across the interior North and 
   East Bays, and the Diablo and Santa Lucia ranges through the 
   early part of next week

 - Hazardous beach conditions across the Pacific Coast with an
   increased risk for sneaker waves and rip currents through
   Saturday

 - Strong and gusty winds develop over coastal waters north of
   Point Reyes this weekend

&&

.SHORT TERM...
Issued at 1200 AM PDT Sat Aug 1 2026
(Today and tonight)

What a difference 24 hrs makes. Last night we were monitoring heat
signatures from the Woodside Incident and a few patches of stratus
on the satellite. Tonight no heat signatures and stratus came back
with solid coverage over the coastal waters and locally inland.
Near-term hi-res models have a decent handle on the current
stratus pattern. The marine layer has deepened overnight to near
800-1000 feet. Expect stratus to linger into the morning then fade
pretty quick as a weak cold front approaches from the north. This
cold front will be dry in nature, but help mix out the marine
layer and set the stage for a rapid increase in N-S gradient. The
bigger impact to today weather wise will be the heat, especially 
the heat across the far interior. Regions that are being impacted 
by the marine layer have the best chance of fully tapping into the
850mb temps in the upper 20C range. That would push temps above 
100 again with the hotspots going for 110. Widespread HeatRisk of 
Moderate with some Major across interior Central Coast. Simply 
put, if you're doing outdoor activities away from the coast today 
be mindful and take some heat safety precautions. If you're 
seeking relief from the heat and want the natural AC at the coast 
you'll get it with highs in the 60s to 80s. Still energetic surf 
zone so use caution at the beaches. Beaches section below for more
info.

By this evening and early tonight the cold front will enter the
northern waters, but washout. The fading front will help to
establish a rapidly increasing N-S gradient from SFO-ACV. 
Previous projections put the gradient near -9mb, but tonight's 
model guidance have eased just under -8mb. Despite the drop, the 
increasing gradient will mix out the stratus and ramp up the wind.
Hi-res guidance still shows some dangerous Storm Force gusts 
north of Pt Reyes. Thankfully the strong winds stay mostly 
parallel to the coast. Aiding in less clouds tonight will also 
come from a weak burst of offshore flow over the N Bay and Central
Coast. 

&&

.LONG TERM...
Issued at 1200 AM PDT Sat Aug 1 2026
(Sunday through Friday)

Subtle cooling each day from Sunday through Wednesday thanks to a
flattening upper level ridge with a passing trough to the north.
Widespread Moderate HeatRisk across the interior will decrease in
coverage through Wednesday. Still expect breezy conditions each
afternoon/evening with onshore flow. The exception will be a
strong offshore flow burst Sunday night into Monday. Not strong
enough for a Wind Adv, but definitely elevate Fire Weather
concerns. 

Longer range guidance and official forecast shows a rebound in
temperatures Thursday and Friday as the ridge re-builds over the
region.

&&

.AVIATION...
(12Z TAFS)
Issued at 413 AM PDT Sat Aug 1 2026

Stratus is moving in across the Bay Area and Central Coast with
CIGs largely IFR. Moderate confidence that CIGs will stay IFR but
coastal sites will be more LIFR to IFR. Added in a tempo for IFR
conditions to STS given moist conditions at STS and northwards
push of Sonoma in Marin/Sonoma Counties. No major changes to
stratus clearing times with models in good agreement of clearing
between 16-18Z. Gusty onshore winds return during the 
afternoon/evening before weakening overnight. Stratus returns
again tonight but current model guidance (emphasis on HREF) shows
a smaller footprint than what we observed tonight. This is
supported by the marine layer compressing to around 500 ft with
CIGs largely expected to be on the LIFR-IFR border. Stratus
returns around 03-06Z along the coast and around 10-12Z across the
interior.

Vicinity of SFO...IFR CIGs continue through late this morning
before VFR conditions return this afternoon and evening. LAMP
guidance shows a low (<30%) chance of LIFR CIGs developing between
12 to 16Z. Confidence is higher that CIGs will stay IFR at SFO
than drop into LIFR territory. Gusty onshore winds return this
afternoon and evening with gusts to around 28 knots possible.
Winds ease overnight with stratus to return around 10Z.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...LIFR-IFR CIGs continue through late this
morning before VFR returns this afternoon/evening. Confidence is
high that stratus will return this evening but timing confidence
is low. An earlier arrival of stratus fits better with the pattern
but LAMP guidance suggests a slightly later arrival of stratus
tonight. LAMP guidance keeps stratus arrival closer to 06Z at both
sites whereas stratus typically returns earlier (02-03Z). For now,
kept an earlier return of stratus but this may need to be amended.
Breezy onshore winds return this afternoon/evening before winds
ease overnight.

&&

.MARINE...
(Today through Thursday)
Issued at 229 AM PDT Sat Aug 1 2026

Hazardous conditions for small craft continue across the coastal
waters through this weekend. Widespread strong to near gale force
winds persist across the coastal waters with gale force gusts
across the northern waters and Big Sur coast. Occasional storm
force gusts are possible across the northern outer waters today
into tomorrow. Rough to very rough wind driven seas will build,
particularly across the northern outer waters, to between 12 to
15 ft. Winds decrease and seas subside through the first half of
next week. Weakening long period swell continues through the
weekend.

&&

.FIRE WEATHER...
Issued at 1216 PM PDT Thu Jul 30 2026

The overall fire weather picture remains similar to the previous
discussion, with elevated fire weather threats persisting at the
higher elevations through the weekend and possibly beyond. 
Overnight RH recovery remains moderate to poor at locations at or 
above 2,000 feet with values between 35 to 45 percent, with some 
favored locations struggling to even reach 25 percent. This will 
be particularly true across the Mayacamas, highest peaks of the 
East Bay Hills, the Diablo Range, the Santa Cruz Mountains, the 
Santa Lucia and Gabilan Ranges. Nocturnal drying (rapid decrease 
in RH through the pre- dawn hours) may also transpire which will 
increase the burn period or time in which fire behavior may remain
active. Afternoon RH remains critically dry with values between 
15 and 30 percent, with far southern portions of the interior 
Central Coast potentially seeing min RH near 10 percent. Energy 
Release Components (ERC) are projected to climb above the 97th 
percentile across the interior Central Coast. Individuals across 
the area are advised to avoid activities that may spark a fire. 
Fire crews are urged to exercise extra caution when executing any 
prescribed burns, especially where fuels, topography, and weather 
align. 

&&

.BEACHES...
Issued at 229 AM PDT Sat Aug 1 2026

Long period southerly to southwesterly swell continues through 
Saturday afternoon, bringing hazardous beach conditions to the 
Central Coast and the San Francisco Bay Area. Southerly swell will
weaken by late this afternoon with conditions to drop below Beach
Hazards Statement criteria. Diminishing, low long period (1-2 ft 
at 13 to 14 seconds) southerly swell will continue into next week. 
Sneaker waves and strong rip currents will be the primary threats
through the duration of the Beach Hazards Statement, with 
breaking waves up to 10 feet along some south and southwest facing
beaches and break points, such as Santa Cruz, Pacifica, and parts
of Stinson or Ocean Beach. This can be particularly surprising 
when wave heights increase suddenly after a period of seemingly 
tranquil wave action. In fact, sneaker waves can have 20+ minutes 
in between the larger sets (breaking waves) with significant 
"flat/calm looking" times between them. Due to the long period, 
sneaker waves are powerful and can catch beachgoers by surprise, 
resulting in people and pets being swept into the cold, turbulent 
ocean. Rip currents are strong enough to pull even the strongest 
swimmers away from shore. Check marine conditions before you head 
out! Swim near a lifeguard, if possible. Maintain a safe distance 
from the water, and stay away from jetties, piers, beachside 
rocks, and other waterside infrastructure. Never turn your back to
the ocean and if you have small children or pets at the beach, 
please keep an eye on them.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through this afternoon for CAZ006-505-
     509-529-530.

PZ...Small Craft Advisory until 9 AM PDT this morning for Pt Arena to 
     Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.

     Gale Warning from 9 AM this morning to 9 PM PDT Sunday for Pt 
     Arena to Pt Reyes 0-10 nm.

     Small Craft Advisory until 5 AM PDT Sunday for Pt Reyes to 
     Pigeon Pt 0-10 nm.

     Small Craft Advisory from 9 AM this morning to 5 AM PDT Sunday 
     for Pigeon Pt to Pt Pinos 0-10 nm.

     Small Craft Advisory until 3 PM PDT this afternoon for Pt Pinos 
     to Pt Piedras Blancas 0-10 nm.

     Gale Warning from 3 PM this afternoon to 9 PM PDT this evening 
     for Pt Pinos to Pt Piedras Blancas 0-10 nm.

     Gale Warning from 9 AM this morning to 3 AM PDT Monday for Pt 
     Arena to Pt Reyes 10-60 NM.

     Small Craft Advisory until 9 AM PDT Monday for Pigeon Pt to Pt 
     Pinos 10-60 NM.

&&

$$

SHORT TERM...MM
LONG TERM....MM
AVIATION...Kennedy
MARINE...Kennedy

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Prepared by Boulder-Creek.com Weather at: Sat Aug 1 04:30:02 PDT 2026