FXUS66 KMTR 072331
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
431 PM PDT Fri Aug 7 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1211 PM PDT Fri Aug 7 2026
- Warming trend through the weekend will result in moderate to
major HeatRisk for the interior
- Near-critical fire weather conditions in the higher terrain
through Sunday
- Minor coastal flooding for bayshore locations along the San
Francisco, San Pablo, and Monterey Bays this evening through
next Thursday morning
&&
.SHORT TERM...
Issued at 1211 PM PDT Fri Aug 7 2026
(This evening through Sunday night)
The warming trend will begin today and persist through the
weekend as high pressure over the Desert Southwest builds
westward. Thus, Heat Advisories remain in effect for all of the
Interior Bay Area and Central Coast from 10 AM Saturday through 10
PM Sunday. The exception is the North Bay Valleys where we have
temperatures forecast to be in the mid 80s to mid 90s. However,
places such as Cloverdale is forecast to be the hottest and are
expected to exceed 100 deg F. Temperatures under the Heat Advisory
are forecast to warm into the mid 90s and up to 105 deg F in the
warmest interior locations where the most widespread moderate to
isolated major HeatRisk are present. Overnight lows are also
forecast to be warm in the mid 60s in the hills just above the
marine influences to low 80s (especially in the higher
elevations). Maximum temperatures closer to the coast are forecast
to be in the 60s to mid 70s thanks to the continued onshore flow
and marine influences. Overnight lows near the coast are largely
forecast to be in the 50s over the weekend.
During this weekends heat event, remember:
* Stay hydrated and drink plenty of fluids.
* Wear lightweight and 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.
Minor coastal flooding is also expected at the time of peak high
tide (evening/overnight) for bayshore locations along the San
Francisco, San Pablo, and Monterey Bays this evening through next
Thursday morning. Please see the CFW product we have out for
additional details.
&&
.LONG TERM...
Issued at 1211 PM PDT Fri Aug 7 2026
(Monday through next Thursday)
Temperatures begin a cooling trend on Monday as the ridge starts
to flatten, yet the interior will still be quite warm. Northerly
winds are forecast to increase and will result in hazardous
conditions to small craft early next week as well, especially
across the northern waters. Temperatures are then forecast to cool
to below seasonal averages late next week as troughing develops
off of the West Coast.
&&
.AVIATION...
(00Z TAFS)
Issued at 431 PM PDT Fri Aug 7 2026
Patchy MVFR-IFR stratus lingers at the immediate coast with high
clouds over portions of the North Bay and the San Mateo Peninsula.
Breezy and gusty onshore pattern winds continue into the evening
hours. Overnight, stratus will gradually expand inland, with
moderate to high confidence that the marine layer will compress as
an upper level ridge builds over the region. If this compression
does not occur, SJC could receive an MVFR ceiling early Saturday
morning. Stratus will retreat to the immediate coast through
Saturday morning with breezy onshore winds resuming in the afternoon.
Vicinity of SFO... VFR through the evening hours with moderate and
gusty northwest winds. Moderate confidence that a ceiling will
develop over the terminal early Saturday morning, with some high
resolution model output depicting the stratus deck deflected to the
north of the terminal. Stratus dissipates over the post-sunrise
hours and breezy west-northwest winds develop Saturday afternoon.
SFO Bridge Approach... Similar to SFO.
Monterey Bay Terminals... VFR conditions continue for a couple of
hours before IFR-LIFR stratus moves over the terminals early this
evening, dissipating through the course of Saturday afternoon.
Breezy northwest winds will diminish this evening and resume
Saturday afternoon.
&&
.MARINE...
(Tonight through next Wednesday)
Issued at 431 PM PDT Fri Aug 7 2026
Moderate northwest seas gradually build to rough (9-12 feet) as
northwest winds increase to fresh to strong by Saturday. Seas and
winds remain elevated through the middle of next week. Embedded
near gale force gusts are possible across the outer northern
coastal waters. A long period southerly swell (15 to 17 seconds)
persists through the weekend.
&&
.FIRE WEATHER...
Issued at 1211 AM PDT Fri Aug 7 2026
Near-critical fire weather conditions persist through the weekend
across the interior due to very hot and dry conditions. Strong
thermal belting, extended burn periods, elevated PIG, and near or
record BI/ERC values are expected. Temperatures will be 10 to 15
degrees above normal with a compressed marine layer. Poor minimum
daytime relative humidity as low as 10% in the afternoons with
little-to-no recovery overnight is expected with nocturnal drying in
the highest terrain. Even with critically dry conditions, wind is
the limiting factor preventing this from being a Fire Weather
Watch/Red Flag Warning event. Outside of the diurnal sea breeze that
will bring breezy conditions in the afternoons and evenings through
gaps and passes, onshore flow will be light. Additionally, critical
conditions are not expected to meet coverage or duration
requirements to warrant a product.
Sarment
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 2 AM PDT Thursday for CAZ006-506-
508-529-530.
Heat Advisory from 10 AM Saturday to 10 PM PDT Sunday for CAZ503-
504-510-512>518.
PZ...Small Craft Advisory from 3 PM Saturday to 9 AM PDT Sunday for
Pt Arena to Pt Reyes 10-60 NM.
&&
$$
SHORT TERM...RGass
LONG TERM....RGass
AVIATION...DialH
MARINE...Navarrete
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Prepared by Boulder-Creek.com Weather at: Fri Aug 7 20:30:03 PDT 2026
From the National Weather Service
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