Cotati, California Weather Forecast Discussion

410
FXUS66 KMTR 061132
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
432 AM PDT Mon Oct 6 2025
...New SHORT TERM, LONG TERM, AVIATION, MARINE...
.KEY MESSAGES...
Updated at 418 AM PDT Mon Oct 6 2025
- Warmer and drier conditions through midweek, with moderate
   offshore wind expected today and Tuesday in the higher
   elevations
- Unsettled weather returns late this week
&&
.SHORT TERM...
Issued at 418 AM PDT Mon Oct 6 2025
(Today and tonight)
A relatively weak offshore upper level low will slowly retrograde
during the day today while maintaining a fetch of weak offshore
flow that will tame the marine layer from making progress inland.
Low stratus should remain offshore and be patchy (if present at
all) throughout the day from Monterey Bay down the Big Sur
coastline. With offshore flow today we`ll see warmer than normal
temperatures, with coastal communities feeling the biggest
difference without much help from the marine layer. Overnight lows
into Tuesday will be 5-10 degrees above normal with some elevated
locations in the thermal belts 15+ degrees above normal along
with poor RH recovery.
&&
.LONG TERM...
Issued at 418 AM PDT Mon Oct 6 2025
(Tuesday through Sunday)
Offshore flow will continue to influence max temps on Tuesday,
with lesser certainty near the coast given weak mixed/to
occasionally offshore flow late Tuesday morning into Tuesday
evening. By Wednesday a weak offshore surface trough located
somewhere between the Bay Area and the Big Sur coastline will
further complicate low- layer vertical wind profiles, however
temperatures overall across the the region will be cooler as the
upper level disturbance begins to evolve into an open wave, move
onshore and merge with a deepening trough to the north. The
relatively weak/mixed low level flow along the coast should begin
to become more steadily onshore by late Thursday into Friday. Rain
chance increase Friday into the weekend, however there is still a
lack of consensus in the overall synoptic pattern, along with the
presence of a tropical system in the SE Pacific to further
confuse the NWP models.
&&
.AVIATION...
(12Z TAFS)
Issued at 418 AM PDT Mon Oct 6 2025
Good flying conditions today as light offshore winds keep stratus
under control. Currently VFR across the board (exception KHAF,
expected to clear by sunrise). Dry air from light offshore winds
is resulting in clear skies across much of the region and will
remain that way through today. A couple of exceptions will be
Monterey Bay terminals (see below) and KSTS which has a slight
chance of seeing some local FG impacts around sunrise.
Vicinity of SFO...VFR. Biggest aviation impact this period will be
light offshore winds. Today and Tuesday, anticipating light NE
winds during the morning hours until just after noon when onshore
flow kicks in.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...VFR through today. As offshore pressure
gradient weakens, marine stratus returns tonight into Tuesday
morning. Low confidence in coverage since some dry air will still
be lingering, and the marine layer will take some time to reform.
&&
.MARINE...
(Today through Saturday)
Issued at 418 AM PDT Mon Oct 6 2025
A weakening weather pattern over the waters is allowing for winds
and resultant seas to continue to decline. Look for light to
moderate winds and generally low seas for the next couple days.
Locally gusty winds and steep seas are possible around prominent
points and headlands.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&
$$
SHORT TERM...JM
LONG TERM....JM
AVIATION...Behringer
MARINE...Behringer
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NWS MTR Office Area Forecast Discussion