Windsor, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

429
FXUS66 KMTR 071217
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
517 AM PDT Thu Aug 7 2025

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 210 AM PDT Thu Aug 7 2025

 - Patches of Moderate HeatRisk Friday through Monday for interior
   East and South Bays.

 - Seasonally warm conditions through the early part of next week.

 - Elevated fire weather concerns given the warming and drying
   trend coupled with daily afternoon/evening breezes.

&&

.SHORT TERM...
Issued at 210 AM PDT Thu Aug 7 2025
(Today and tonight)

No major changes from the last discussion. Broad troughing sits over
the majority of the West Coast this morning, with the closed low
swinging into the PacNW today. To our east, the upper level ridge
over the Four Corners will continue to flatten. Temperatures for
interior locations today may climb a couple degrees higher while
most locations will be similar to yesterday. As noted before, could
still see some haze/smoke nudge into interior San Benito from the
Gifford Fire to the south on Thursday.

&&

.LONG TERM...
Issued at 210 AM PDT Thu Aug 7 2025
(Friday through Wednesday)

Upper level troughing slides to the east late Thursday into Friday,
as the eastern Pacific high builds into the region. This will hold
through the weekend and into early next week. The only real change
noted in the forecast period is that the warmer weather looks to
hold through Monday. Patches of Moderate HeatRisk are expected
for portions of the East, South, and North Bay while Minor
HeatRisk is expected elsewhere. For those who have to work in or
are looking to enjoy the outdoors, be sure to practice heat
safety. Wear sunscreen, take breaks, hydrate, and look before you
lock your vehicle.

&&

.AVIATION...
(12Z TAFS)
Issued at 516 AM PDT Thu Aug 7 2025

Confidence is low to moderate in timing of stratus arrival this
morning. The Fort Ord profiler shows the marine layer is compressed
to around 800 feet with stratus intrusions mainly limited to the
coast as of the writing of the 12Z TAFs. Continued to lean towards
at least patchy stratus filtering into the SF Bay and impacting SFO,
OAK, and APC through 16Z. Low confidence that stratus will reach STS
with low confidence in fog development due to the presence of high
clouds overnight. For HAF, MRY, and SNS the more compressed marine
layer may lead to temporary drops in visibility with some potential
for fog to develop. This is most likely for HAF and MRY with other
coastal sites (WVI, OAR) reporting visibilities of <1SM and fog this
morning. Conditions improve across the region by mid to late morning
with another round of stratus moving in later this evening.

Confidence is low on the timing of stratus return tonight. Guidance
suggests an early return of stratus across the board but guidance
has been overestimating how fast stratus will return for the past
few days. With upper level ridging building in, the marine layer
will compress with stratus confined primarily to the coast. This
would drop conditions at coastal sites (HAF, MRY) early in the
evening but further inland sites (SFO, OAK, APC, SNS) may not see
drops until later in the night depending on if the marine layer
deepens overnight. For now, confidence is highest in stratus
returning to HAF, MRY, and SNS overnight with low to moderate
confidence in stratus reaching SFO, OAK, and APC.

Vicinity of SFO...Currently VFR with some potential for temporary
MVFR CIGs through 16Z. Confidence is low to moderate as to if CIGs
will reach SFO this morning with the marine layer at approximately
800 ft in depth. Typically we would want the marine layer to be
slightly deeper for stratus to make it to SFO. Guidance is leaning
towards VFR prevailing through the remainder of the morning but
cameras in the vicinity of SFO suggest at least some lower level
clouds are filtering in. Opted to leave a tempo in for MVFR CIGs
through 15Z given cameras showing low clouds in the vicinity.
Otherwise, stratus is likely to return tonight but confidence is low
on the timing. Currently leaning towards stratus returning late in
the evening but guidance (as discussed above) is leaning towards a
widespread stratus return during the early evening hours. Current
thinking is that stratus will take longer to reach SFO than guidance
suggest but will start to fill in closer to 07Z.

SFO Bridge Approach...Potential for loss of VAPs between 12Z-16Z
this morning before VFR through the remainder of the day. Stratus is
likely to return this evening which may result in another lapse in
VAPs later tonight.

Monterey Bay Terminals...LIFR conditions prevail through mid to late
morning before stratus coverage briefly dissipates. Low to moderate
confidence on timing of stratus return with guidance leaning towards
an early return of stratus this evening. Stratus becomes more likely
at MRY by 3Z with a slightly later return (~6Z) for SNS. Current
thinking is that a more compressed marine layer will result in
coastal sites seeing an earlier stratus return while sites farther
inland will see a later stratus return depending on how far inland
stratus is able to progress.

&&

.MARINE...
(Today through Tuesday)
Issued at 516 AM PDT Thu Aug 7 2025

Widespread fresh to strong northwesterly gusts continue through
the  remainder of Thursday across the coastal waters. Winds
strengthen  across the northern outer waters Thursday afternoon
and evening with  near gale force gusts anticipated. Winds
diminish overnight Thursday  throughout the day on Friday with a
gentle to moderate breeze  prevailing through the weekend. Seas
briefly build to 10 to 12 feet  across the northern outer waters
on Friday before diminishing over  the weekend.

&&

.FIRE WEATHER...
Issued at 937 AM PDT Wed Aug 6 2025

After coordination calls this morning with fire partners we`ll be
hoisting a headline for the afternoon fire weather forecast. The
headline will mainly focus on the increasing temperatures coupled
with the lower humidity Friday and over the weekend. The greatest
areas of concern will be the higher terrain and interior
locations. Low elevations will see better humidity recovery, but
higher terrain will be persistently dry. Daily sea breeze pushes
occuring during peak heating will also elevate concerns.

Taking a look at the Hot Dry Windy index also highlights concerns
pushing values into the 95th percentile later in the weekend and
early next week.

MM

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 PM PDT this evening for Pt Arena to
     Pt Reyes 0-10 nm.

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

     Small Craft Advisory until 3 PM PDT Friday for Pt Arena to Pt
     Reyes 10-60 NM.

&&

$$

SHORT TERM...KR
LONG TERM....KR
AVIATION...Kennedy
MARINE...Kennedy

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