FXUS66 KMTR 301928
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
1228 PM PDT Thu Jul 30 2026

...New SHORT TERM, LONG TERM, BEACHES, FIRE WEATHER...

.KEY MESSAGES...
Updated at 1216 PM PDT Thu Jul 30 2026

 - Gradual warming trend through Saturday 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 the
   weekend

&&

.SHORT TERM...
Issued at 1216 PM PDT Thu Jul 30 2026
(This evening through Friday night)

Generally clear skies prevail over the region with limited patches 
of stratus lingering over the western side of San Francisco, along 
the coast of the San Mateo Peninsula down to Pillar Point, and at 
the immediate coast of the Monterey Bay region. Today will be the 
first day of a warming trend that will dominate the weather pattern 
for the next few days and bring temperatures above seasonal averages 
to the inland regions, driven by a building high pressure system 
expanding into California from the Desert Southwest. High 
temperatures will range from the middle 80s to middle 90s across the 
inland valleys, up to around 102 within the warmest spots of 
southern Monterey and San Benito Counties, the lower 70s to lower 
80s along the Bays, and the lower to middle 60s along the Pacific 
coast. An onshore push will develop this afternoon and evening, 
bringing gusts of 25 to 35 mph along the coast, through gaps and 
passes, and within the Salinas Valley. 

Tonight, expect the building high pressure system to compress the 
marine layer, limiting any stratus and fog impacts to the immediate 
coastal regions. Low temperatures on Friday morning range from the 
middle to upper 50s in the valleys, to the 60s and lower 70s within 
the thermal belts. Highs on Friday will continue to warm with 
temperatures around a couple degrees warmer than today's across most 
of the region, save the immediate coast where the compressed marine 
layer keeps the region cooler.

Patches of Moderate HeatRisk develop in the interior on Friday, 
followed by more widespread Moderate HeatRisk in the interior 
Saturday through the early part of next week. This corresponds to a 
moderate risk for heat related illnesses for sensitive populations, 
including children, the elderly, pregnant women, people with certain 
medical conditions, and people who work or live outdoors without 
adequate shelter or hydration. Follow these tips to avoid heat-
related illnesses:

* Stay hydrated and drink plenty of fluids.
* Wear lightweight, light-colored clothing.
* Reduce time spent outdoors or stay in the shade.
* Never leave people or pets unattended in vehicles.
* Use sunscreen if going to the coast or the pool.

&&

.LONG TERM...
Issued at 1216 PM PDT Thu Jul 30 2026
(Saturday through next Wednesday)

Saturday looks to be the warmest day of this strand of warming with 
triple digit highs possible in the far interior regions of northern 
Sonoma, northeastern Napa, and eastern Contra Costa counties, while 
southern Monterey County sees highs reaching 105 with some isolated 
and heavily favored locations making a run for 110. Elsewhere the 
inland valleys remain in the 90s while downtown San Francisco and 
Oakland hover in the middle 70s to lower 80s. On Sunday, a trough 
passing by the Pacific Northwest will interrupt the building ridge 
and cause temperatures to plateau, but large scale ridging returns 
the next day and could continue into the middle of the next week. 

Regarding potential strong winds across the coastal waters this 
weekend, the ECMWF EFI backed down a little bit from what the 
previous forecaster was seeing last night, but are still showing 
high EFI values with a strong shift of tails. Or in layman's terms, 
there's a strong signal for strong winds and a relatively high 
probability for remarkably strong winds, a "boom" situation, if you 
will. The PG&E WRF model continues to show a swath of storm force 
gusts over 60 mph across the northern waters off the coast of Sonoma 
and Marin counties, but it's almost alone in depicting this, with 
the deterministic GFS and the experimental RRFS showing isolated 
storm force gusts in the area while the NAM12 and deterministic 
ECMWF keep wind gusts at gale force. Will be interesting how the 
other high resolution models, namely the higher-resolution NAM and 
the HRRR, depict the wind gusts in this are where the time comes. 
For now, there wasn't enough confidence to bump up the wind gusts 
for the weekend. 

In addition, the upper level pattern could bring us a couple of 
offshore bursts over the region, with a notable pulse Sunday night 
into Monday particularly across the North Bay and SF Bay regions. As 
noted by the previous forecaster, the fire weather concerns 
regarding nocturnal drying and downslope warming are obvious, but 
that downslope warming could also cause coastal temperatures to be 
much warmer than the forecast if it extends through Monday.

As a final note, beach hazards and fire weather concerns continue 
into the weekend. See the BEACHES and FIRE WEATHER sections for more 
details. One less spark, one less fire, and never turn your back to 
the ocean!

&&

.AVIATION...
(18Z TAFS)
Issued at 1124 AM PDT Thu Jul 30 2026

Beginning the day with widespread VFR conditions, yay! Onshore winds 
increase to 10-15 kt by the early afternoon and ease to ~5 kt 
overnight. Winds at STS and APC remain more S-SW meanwhile sites 
located south of the Golden Gate remain W-NW. As the ridge continues 
to move westward and the 500 mb heights over our region increase, 
the marine layer tonight will be compressed to around 1000 feet or 
less. This will confine stratus coverage to coastal sites only (HAF, 
MRY, and SNS), potentially bringing borderline IFR-LIFR ceilings. 
The compressed marine layer increases the chances for patchy coastal 
drizzle and fog, though confidence is low on the exact duration and 
timing. Elsewhere should remain VFR through the TAF period.

Vicinity of SFO...Gentle onshore breezes increase to ~15 kt this 
afternoon (20-21Z) with SFO experiencing another round of gusts 
around 25 kt. Low confidence on the development of MVFR ceilings 
this TAF period. Most model guidance (HREF, REFS, LAMP, and NBM) 
tends to agree on limited stratus coverage tonight. If the marine 
layer deepens beyond 1000 feet, there may be a chance for stratus to 
trickle over SFO and OAK around 10-12Z. However, the atmosphere 
seems to be to dry at 925 mb and above, which helps to limit the 
expansion of stratus.

SFO Bridge Approach...Similar to SFO. Winds may be a couple knots 
lower than SFO.

Monterey Bay Terminals...VFR through the day. Onshore winds increase 
to ~10-12 kt this afternoon with gusts around 18-22 kt. A compressed 
marine layer will also delay the arrival of IFR ceilings compared to 
the previous night. As a result, they may arrive around 11-13Z, 
impacting MRY first and then SNS. Ceilings may intermittently become 
LIFR at OVC003-004, but low confidence on the exact timing. If 
conditions do become LIFR, coastal drizzle and patchy fog is 
possible which will impact visibility to around 1-2 SM. MRY has a 
higher chance of visibility impacts under these conditions compared 
to SNS. 

&&

.MARINE...
(Today through Tuesday)
Issued at 908 AM PDT Thu Jul 30 2026

Northwesterly breezes remain fresh to strong with embedded near
gale  force gusts into the weekend. Wind driven moderate seas
build to  rough by Sunday. Northwest winds increase to gale by the
end of the  weekend as well. Our coastal waters continue to
experience a long  period southerly swell from distant tropical
activity.

&&

.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 1216 PM PDT Thu Jul 30 2026

Long period southerly to southwesterly swell of 14-17 seconds 
continues to impact our coastline through at least Saturday
afternoon, bringing hazardous beach conditions to the Central 
Coast and the San Francisco Bay Area. Sneaker waves and strong rip
currents will be the primary threats, 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 Saturday afternoon for CAZ006-
     505-509-529-530.

PZ...Small Craft Advisory until 9 PM PDT this evening for Mry Bay-SF 
     Bay N of Bay Bridge.

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

     Gale Warning from 9 AM to 3 PM PDT Saturday for Pt Arena to Pt 
     Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.

     Small Craft Advisory until 9 PM PDT this evening for Pt Reyes to 
     Pigeon Pt 0-10 nm.

     Small Craft Advisory from 3 PM Friday to 3 PM PDT Saturday for 
     Pt Reyes to Pigeon Pt 0-10 nm.

     Small Craft Advisory until 9 PM PDT Friday for Pigeon Pt to Pt 
     Pinos 0-10 nm.

     Small Craft Advisory from 9 AM to 3 PM PDT Saturday for Pigeon 
     Pt to Pt Pinos 0-10 nm.

     Small Craft Advisory until 3 PM PDT Saturday for Pigeon Pt to Pt 
     Pinos 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm.

&&

$$

SHORT TERM...DialH
LONG TERM....DialH
AVIATION...Navarrete
MARINE...Navarrete

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Prepared by Boulder-Creek.com Weather at: Thu Jul 30 14:30:03 PDT 2026