530
FXUS66 KMTR 152038
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
138 PM PDT Wed Jul 15 2026

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

.KEY MESSAGES...
Updated at 126 PM PDT Wed Jul 15 2026

 - Moderate HeatRisk continues across the interior today

 - Breezy onshore winds through Friday

 - Elevated fire weather conditions through Thursday

&&

.SHORT TERM...
Issued at 138 PM PDT Wed Jul 15 2026
(This evening through Thursday night)

The marine layer is making a good attempt at returning! However, hot
temperatures, very dry conditions, and breezy winds persist across
the interior and higher terrain across the region this afternoon.
With full sunshine, temperatures will warm into the 90s to 103 deg F
(in the warmest interior spots). These temperatures are slightly
cooler than yesterday, yet are up to 10 degrees above seasonal
averages (up to 20 degrees above for the higher elevations). Cooler
temperatures will persist near the coast as onshore winds prevail.
The aforementioned hot, dry, and windy conditions are creating
elevated fire weather conditions across the interior and higher
terrain. Please see the Fire Weather Section of the AFD for more
information.

The marine layer is forecast to deepen to around 500 feet tonight.
However, cloud cover is a bit more uncertain. There is a 30-50%
probability of stratus returning to the coastline and Monterey Bay
during the overnight hours and into early Thursday morning. However,
any low clouds that do develop will quickly dissipate by mid-to-late
morning.

For Thursday afternoon, temperatures generally cool to near seasonal
averages for much of the region as onshore winds increase. This will
lower HeatRisk to Minor category and bring an end to the warming
trend as a mid/upper level trough of low pressure deepens off of the
Pacific Northwest coast. Heading into Thursday night, the marine
layer is forecast to deepen to around 1,000 feet and increase the
potential for low clouds.

&&

.LONG TERM...
Issued at 138 PM PDT Wed Jul 15 2026
(Friday through next Tuesday)

Onshore winds will persist through much of the upcoming weekend and
will allow for the marine layer to deepen and remain steady at
around 1,500 feet. Thus, expect temperatures to remain near to
slightly below normal for mid July with stratus more likely into the
weekend. These low clouds will retreat back to the coast by mid-to-
late morning.

Heading into late weekend and early next week, we are keeping an eye
on monsoon moisture working its way northward around the Southern
Plains` mid/upper level high. However, latest trends indicate the
focus for thunderstorms has shifted to the east over the Sierra
Nevada Sunday into Monday. That said, still expecting mid-to-high
level clouds over the region. This will need to be closely monitored
over the coming days as any high based thunderstorms will likely
result in dry lightning that can spark wildfires.

&&

.AVIATION...
(18Z TAFS)
Issued at 1042 AM PDT Wed Jul 15 2026

VFR conditions prevail across all terminals. High confidence in
VFR through the afternoon with low to moderate confidence on IFR
ceilings returning to the coastal terminals of HAF, MRY, and SNS
tonight. Diurnal winds will prevail.

Vicinity of SFO...Currently VFR with westerly flow. High confidence
in VFR and diurnal winds prevailing through the TAF period. Wind
gusts are anticipated to reach 30 knots with occasional gust to
35 knots possible between 23Z and 03Z this afternoon.

SFO Bridge Approach...Low probability (20-30% chance) of low
clouds below FL045 developing across the San Mateo Bridge Approach
tonight.

Monterey Bay Terminals...VFR conditions prevail with light winds
over MRY and northwesterly winds over SNS. Moderate confidence on
IFR ceilings returning to the terminals tonight.

&&

.MARINE...
(Tonight through next Monday)
Issued at 126 PM PDT Wed Jul 15 2026

Widespread hazardous conditions for small crafts are expected
into Friday across the inner and outer waters due to fresh to
strong northwesterly winds. Gale force gusts are expected along
the coastal jet regions of Point Reyes and Point Sur. The
afternoon sea breeze will create hazardous conditions for small
crafts within the bays. Moderate seas will prevail with
intermittent rough seas in the outer waters through Friday.

&&

.FIRE WEATHER...
Issued at 138 PM PDT Wed Jul 15 2026

The warm temperatures we have had the past several days and
continued warm weather has resulted in fuels rapidly drying this
week. Fire weather concerns will remain elevated this afternoon with
afternoon relative humidity dropping to between 10-20% across the
interior and higher elevations (away from the marine influences),
gusty onshore winds, and very dry fuels. This may result in
additional fire starts particularly across the interior and higher
elevations. These conditions are gradually forecast to improve as
the marine layer returns Thursday and deepens into Friday. Unsettled
weather is possible late this weekend and into early next week with
returning potential for dry thunderstorms and gusty, erratic winds.
However, the focus has shift to the east more over the Sierra
Nevada.

RGass

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 4 AM PDT Thursday for CAZ006-506-
     508.

     Heat Advisory until 10 PM PDT this evening for CAZ516-517.

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

     Small Craft Advisory from 9 AM to 3 PM PDT Thursday for Mry Bay.

     Small Craft Advisory until 3 AM PDT Friday for Pigeon Pt to Pt
     Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 nm-Pt Reyes to
     Pigeon Pt 0-10 nm.

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

     Gale Warning from 9 AM to 8 PM PDT Thursday for Pt Pinos to Pt
     Piedras Blancas 0-10 nm.

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

&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...CW
MARINE...CW

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