199
FXUS66 KMTR 062124
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
224 PM PDT Mon Oct 6 2025

...New SHORT TERM, LONG TERM, MARINE...

.KEY MESSAGES...
Updated at 222 PM PDT Mon Oct 6 2025

 - Warmer and drier conditions through Tuesday, with moderate
   offshore wind expected in the higher elevations

 - Cooler, unsettled weather returns late this week

&&

.SHORT TERM...
Issued at 222 PM PDT Mon Oct 6 2025
(This evening through Tuesday)

Offshore winds prevail in the higher elevations this afternoon, yet
that remain weak to moderate in strength. This has allowed for
temperatures to rapidly warm into the mid 70s to lower 80s across
much of the region. Slightly cooler conditions prevail along the
immediate coast where onshore winds have returned. Temperatures this
afternoon will peak in the low to mid 70s along the immediate
coastline with low to upper 80s across inland areas. Downtown San
Francisco has around a 14% probability of exceeding 85 degrees F
with southeast portions of the city at around 30%. Places such as
Novato, San Rafael, San Mateo, Redwood City, and Gilroy have a 30-
60% chance of exceeding 90 degrees F.

Temperature begin to cool just before sunset with overnight lows
dropping into the mid 50s to lower 60s across much of the region.
Low clouds and/or fog have the greatest potential for reaching the
San Mateo Peninsula and around the Monterey Bay region late tonight
and into early tomorrow morning. However, any low clouds/fog that do
develop will quickly retreat to the coast by mid morning.

Offshore winds will increase once again tonight, yet are expected to
be weaker than this morning. They will be strongest in the North Bay
and East Bay higher elevations. As such, Tuesday will be equally as
warm as today with the interior warming by a few degrees. However,
coastal locations have the potential to be a few degrees cooler than
today depending on when onshore flow returns.

&&

.LONG TERM...
Issued at 222 PM PDT Mon Oct 6 2025
(Tuesday night through next Sunday)

Onshore flow will return regionwide on Wednesday as an upper level
trough approaches the Pacific Northwest coast. This will result in a
significant cool down with temperatures returning to near or below
seasonal averages. Chances for rain return by early Friday morning
as a frontal boundary approaches the North Bay. The boundary is
forecast to shift southward through the day on Friday and into
Friday night bringing rain chances as far south as the Santa Cruz
Mountains. There remains a great deal of uncertainty on the on
potential for rain through the weekend as there is a lack of
consensus in the overall synoptic pattern. Be sure to stay up-to-
date with the latest forecast information as we get closer to the
weekend.

&&

.AVIATION...
(18Z TAFS)
Issued at 1107 AM PDT Mon Oct 6 2025

VFR at all terminals today with light offshore winds this morning
becoming light onshore this afternoon. Offshore winds will return
again tonight allowing for most terminals to remain VFR through
the night. The exception will be immediate coastal terminals where
low level moisture will return tonight and may bring in very low
clouds under the light offshore flow. This should be confined to
the Pacific coast terminals such as MRY and HAF.

Vicinity of SFO...VFR. Light offshore winds, just above the
surface, will maintain VFR for most of the day. Afternoon surface
winds should become NW, but not very strong. This will help to cap
the temperature rise. Tonight winds will go calm and some low
level moisture will attempt to work its way around the corner at
the golden gate, but should be thwarted by the dry air locked up
inland and over the immediately adjacent bay. If there was going
to be a caveat to this forecast, it would be to say something
about a very low probability of some ground fog (BCFG) or very
low clouds (few002) creeping around late in the nighttime hours or
about sunrise. The odds of this happening are so low though, it
did not make the official forecast. Tuesday will bring another VFR
warm day.

SFO Bridge Approach...Similar to SFO. VFR will dominate.

Monterey Bay Terminals...VFR. Overnight there is a good shot at
some low level humidity making it to the area, coming up from the
south. This low level humidity will bring some low clouds and
visibility reductions. How this plays out, low clouds versus low
visibility, will depend on how shallow the marine layer actually
stays. Either way, we`re looking at IFR or LIFR for a few hours in
the AM before it breaks out again.

&&

.MARINE...
(Today through Saturday)
Issued at 222 PM PDT Mon Oct 6 2025

Light to moderate winds accompanied by low to moderate seas will
prevail through Tuesday. An approaching system will begin to
increase winds and seas mid to late week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.
&&

$$

SHORT TERM...RGass
LONG TERM....RGass
AVIATION...BFG
MARINE...BFG

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