FXUS66 KMTR 071913
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
1213 PM PDT Fri Aug 7 2026
...New SHORT TERM, LONG TERM...
.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...
(18Z TAFS)
Issued at 1133 AM PDT Fri Aug 7 2026
Widespread VFR conditions are expected to settle in by noon today,
except at KHAF where they have a low chance of scattering out this
afternoon. Moderate onshore winds increase to 10-15 kt this
afternoon and become light overnight. The marine layer returns to
most terminals tonight after 02-03Z Saturday for coastal sites and
after 06-07Z Saturday for inland areas. It has been around 1200-1500
feet the past few days, though there is potential for it to compress
down to 1000-1200 feet as the upper-level ridge continues to move
westward. If the marine layer remains at the same depth, MVFR
ceilings may develop around 12Z at KSJC.
Vicinity of SFO...West to northwest winds increase to around 15-18
kt this afternoon and ease to around 5-10 kt overnight. Medium to
high confidence for IFR ceilings to develop around 06-10Z Saturday
as the marine layer gradually becomes compressed these next couple of
days. Stratus should clear around the same time as today, 17-18Z
Saturday.
SFO Bridge Approach...Similar to SFO. May have more of a SCT cloud
deck than a BKN/OVC ceiling. If KSJC develops a ceiling, the bridge
approach may develop one as well.
Monterey Bay Terminals...VFR through the afternoon with NW winds
around 10-14 kt. Borderline IFR-LIFR ceilings (OVC005-007) develop
again tonight with visibility impacts (4-6SM) possible at KMRY.
Medium confidence on stratus arrival as it may roll in between 02-
07Z Saturday and persist until 17-18Z tomorrow.
&&
.MARINE...
(Today through Wednesday)
Issued at 950 AM PDT Fri Aug 7 2026
Moderate northwest winds continue on a gradual increase towards
fresh to strong breezes with moderate seas building to rough by
Sunday. These conditions remain elevated through the middle of
next week, particularly across the northern outer waters. A long
period southerly swell around 15 to 17 seconds persists through
Monday.
&&
.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 from 5 PM this afternoon to 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 to 9 PM PDT Saturday for Pt Arena
to Pt Reyes 10-60 NM.
&&
$$
SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Navarrete
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: Fri Aug 7 12:30:02 PDT 2026
From the National Weather Service
|