833
FXUS66 KMTR 182308
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
408 PM PDT Fri Jul 18 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 209 PM PDT Fri Jul 18 2025

 - Seasonal temperatures through the end of the weekend. Below
   normal temperatures return Monday.

 - Localized elevated fire weather threat continues across the
   higher elevations with dry conditions expected this weekend.

 - Winds strengthen Sunday and Monday along the coast, the higher
   terrain, and mountain gaps/passes.

&&

.SHORT TERM...
Issued at 209 PM PDT Fri Jul 18 2025
(This evening through Saturday)

While the morning was overcast across much of the region, stratus
has now dissipated across much of the interior. Building high
pressure is expected to compress the marine layer to around 1500
feet tonight. This is still a fairly deep marine layer so we can
expect stratus to return across much of the Bay Area and Central
Coast by late tonight into early tomorrow morning. Stratus will
clear by late tomorrow morning across the interior with clearing
occurring for portions of the coastline. Further compression of the
marine layer is expected Saturday night into Sunday as high pressure
strengthens over the Central Coast with the marine layer depth
dropping to around 1200 feet.

Seasonal temperatures will continue again on Saturday as a slight
warming trend continues. For the Bay Area, temperatures will stay in
the upper 70s to low 80s along the bay shoreline with highs in the
mid to upper 80s farther inland. Coastal areas will remain
comparatively cooler with highs in the upper 50s to mid 60s on
Saturday. The interior Central Coast however will be quite a bit
warmer with high temperatures in the mid to upper 90s. Portions of
far southern Monterey County in the vicinity of Fort Hunter Liggett,
Bradley, and Parkfield have 40% chance of temperatures reaching the
100 degree mark. Temperatures cool down into the 50s overnight
across the Salinas Valley and upper 50s to mid 60s across the higher
terrain. This results in Minor HeatRisk across the Bay Area and
Central Coast with only a few pixels of Moderate HeatRisk in the Los
Padres National Forest.

Localized fire weather concerns continue in particular for the
interior Central Coast and East Bay Hills. For the interior Central
Coast, daytime conditions are expected to further dry Saturday and
poor daytime humidity values between 13 to 25 percent expected.
Fortunately, winds remain light and onshore across the higher
terrain, where the driest conditions are, which will help mitigate
concerns a little. The Salinas Valley, comparatively, will continue
to experience breezy afternoon/evening winds with gusts to around 30
to 35 mph. Conditions are not quite as dry in the Salinas Valley but
occasional moderate gusts (up to 25 mph) may push into the far
southern Salinas Valley (vicinity of Bradley) where conditions are
drier. For the East Bay Hills, we can expect dry daytime conditions
(humidity values between 25 to 30%) and breezy afternoon winds to
around 35 mph across mountain gaps/passes to continue through the
remainder of the weekend.

&&

.LONG TERM...
Issued at 209 PM PDT Fri Jul 18 2025
(Saturday night through next Thursday)

Weather wise, Sunday looks to be a repeat of Saturday with
temperatures in the upper 70s to 80s across the interior with a few
hot spots in the East Bay reaching the low 90s. Highs across the
interior Central Coast will start cool, if ever so slightly, with
highs peaking in the mid to upper 90s compared to upper 90s to low
100s anticipated on Saturday. While high pressure remains situated
over much of California on Sunday, it does start to break down
late in the day as another upper level trough moves into
California. As this trough approaches, it will increase onshore
flow and allow gusty winds to develop Sunday afternoon along the
coast and across mountain gaps/passes throughout the interior.
Gusty winds will become more widespread on Monday across the North
Bay, San Pablo and Suisun Bays, along the delta, and across the
East Bay hills (emphasizing mountain gaps/passes). Gusts are
expected to peak around 30 mph across the North Bay but will peak
closer to 35-40 mph across portions of the delta and East Bay
Hills (Altamont Pass).

Hopefully you aren`t tired of No Sky July and comparatively mild
temperatures as the arrival of this trough will also kick off a
cooling trend and bring a return to below normal temperatures
across the region. Temperatures across the interior will drop back
into the 70s to low 80s and remain that way through the end of
the week as troughing continues. The exception will again be the
interior Central Coast where temperatures will only drop into the
upper 80s to low 90s. All in all, the CPC indicates below normal
temperatures are likely to persist through late July with near
normal temperatures to persist into the first few days of August.

In terms of fire weather concerns, localized concerns will still
exist across the highest elevations but the return of upper level
troughing will help to mitigate more widespread concerns. Increased
onshore flow will allow for modest improvements in daytime humidity
values starting Monday. This is most noticeable across the
interior Central Coast where daytime minimum values will improve
from around 13 to 20% over the weekend to 20 to 30% by early next
week.

&&

.AVIATION...
(00Z TAFS)
Issued at 408 PM PDT Fri Jul 18 2025

Patchy MVFR stratus persists at the immediate coast with generally
VFR conditions elsewhere. Breezy and gusty onshore flow continues
through the evening, then diminishing to light winds overnight. High
confidence for MVFR-IFR stratus returning to most of the terminals
overnight through Saturday morning, with clearing times later than
today`s with a slightly compressed marine layer. Low probabilities
of LIFR ceilings are also present overnight through Saturday
morning, with the greatest potential in the North Bay and
Monterey Bay regions. Breezy onshore flow resumes Saturday afternoon.

Vicinity of SFO... VFR into the evening hours with breezy and gusty
west-northwest winds. Winds diminish in the evening hours with MVFR-
IFR stratus coming in overnight, dissipating rather late on Saturday
morning. Breezy and gusty northwest winds resume Saturday afternoon.
Saturday evening, confidence is low in stratus returning to the
terminal before the end of the TAF period, and it might not be until
early Sunday morning that stratus impacts begin.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... VFR through the next couple of hours, with
stratus overrunning the terminals soon. Ceilings look to be MVFR,
descending to IFR with a low probability of LIFR ceilings. Stratus
retreats to the immediate coast late Saturday morning with moderate
confidence on timing. Breezy northwest winds continue through the
evening hours, becoming light overnight before resuming Saturday
afternoon.

&&

.MARINE...
(Tonight through next Wednesday)
Issued at 209 PM PDT Fri Jul 18 2025

Light to moderate west or northwest breezes continue across the
majority of the coastal waters through this weekend with winds
easing into the upcoming week. Gusty winds, potentially hazardous
to small craft, develop each afternoon and evening through the
Golden Gate, into the Delta, and the favored coastal jets off of
Pigeon Point and the Big Sur coastline. Moderate seas persist
through the remainder of the forecast period.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Saturday for SF Bay N of Bay
     Bridge.

     Small Craft Advisory from 9 AM Saturday to 3 AM PDT Sunday for
     SF Bay N of Bay Bridge.

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

     Small Craft Advisory until 9 AM PDT Saturday for Pt Pinos to Pt
     Piedras Blancas 0-10 nm.

     Small Craft Advisory from 3 PM Saturday to 3 AM PDT Sunday for
     Pt Arena to Pt Reyes 10-60 NM.

&&

$$

SHORT TERM...Kennedy
LONG TERM....Kennedy
AVIATION...DialH
MARINE...RGass

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