Angwin, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

365
FXUS66 KMTR 240553
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
953 PM PST Fri Jan 23 2026

...New AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1209 PM PST Fri Jan 23 2026

 - Gusty offshore winds across higher terrain of the North Bay and
   East Bay Friday night through Sunday morning

 - Morning fog across some Bay Area Valleys

 - Potential weak storm system in the middle of the next work week

&&

.SHORT TERM...
Issued at 1209 PM PST Fri Jan 23 2026
(This evening through Saturday)

Low clouds linger across much of the lower elevations across the
region this afternoon as the return of a ~1500 ft marine layer
returned overnight. In addition, tule fog from the Central Valley as
pushed westward into the East Bay Valleys. By mid afternoon, mostly
sunny sky conditions are forecast expect for locations near the
coast where the marine layer persists.

Expecting offshore winds to develop across the higher elevations of
the North and East Bay valleys tonight and persist into Saturday.
Localized gust may exceed 50 mph in some of the peaks across the
region. This will dry things out considerably in these areas which
may also mix down into the valleys on Saturday. However, winds are
not forecast to be strong in the lower elevations. Afternoon
humidity values are likely to fall below 20% in the higher terrain.

Saturday, we are expecting offshore winds to persist in the higher
terrain. This offshore flow will work to compress the marine layer
and essentially completely mixing it out. Thus, a slight warm up in
temperatures can be expected with low to mid 60s for much of the
region.

&&

.LONG TERM...
Issued at 1209 PM PST Fri Jan 23 2026
(Saturday night through next Thursday)

Offshore winds look to diminish Saturday night into Sunday morning,
yet will still be moderate in the higher terrain. Therefore, low
clouds cover and/or fog will have a difficult time developing early
Sunday morning with continued offshore flow aloft. However, high
clouds will will begin to spread in from the west by that time.

From the previous forecaster: "The ridge looks to flatten into
Sunday evening, with a zonal jetstream pattern taking its place, and
offering more onshore flow. However the jetstream looks to snap back
to a quick ridge into the next work week. This means temperatures
will and some bounces up and down by a few degrees, and low cloud
formation will be spotty.

Despite the quick ridge development, high clouds look to move
through the region as a trough develops to the west. The trough
formation is well-argeed upon between the longer term models, but
the trajectory is a matter of debate. More models point to a cold
front, and maybe a weak low pushing through the area, bringing good
chances for widespread moderate rains by the mid week. However, the
GFS and its ensemble members seem keen on this trough getting pushed
up against the ridge ahead of it, and placing all the moisture well
to the north. The GFS output looks a bit less firm than other models
and the national blend, but is something to keep in mind as the
longer term models update. For now, the official forecast places
rain chances in the middle of the next work week along the initial
front with additional chances possible beyond the forecast
period."

&&

.AVIATION...
(06Z TAFS)
Issued at 953 PM PST Fri Jan 23 2026

Fairly expansive cloud cover across the Bay Area and Central Coast
this evening. Starting to see some visibility fluctuations across
the North Bay and East Bay. CIGs and visibility are expected to drop
overnight with fog developing across the valleys. Providing
uncertainty to the forecast is the arrival of moderate to strong
offshore winds across the higher elevations. This should bring in
much drier air to the region and subsequently cause cloud cover to
be significantly reduced. HREF guidance shows a sharp drop off in
the areal extent of cloud cover starting 12-13Z which is around when
winds pick up. Went with a mixture of earlier clearing times (closer
to 15-16Z) and late morning clearing times (17-18Z). Winds
strengthen to between 10-15 knots during the day before easing
overnight.

Vicinity of SFO...Currently MVFR at SFO with low to moderate
confidence that it will persist past 10Z. For now kept MVFR
conditions as a tempo as all guidance suggests it will clear by
10/11Z. Winds remain variable overnight before becoming
northeasterly to northerly during the day. Winds strengthen to
around 8-10 knots before diminishing again overnight.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...MVFR with low potential for IFR conditions
to develop. Not seeing any indicators of fog developing and or
significant drops in visibility at MRY or SNS tonight so have pulled
up forecast visibilities for SNS. Ceilings look to improve as early
as 15/16Z. Confidence is slightly higher that SNS will clear by 16Z
while MRY clears closer to 17Z. Winds remain NW to N throughout the
day before diminishing and becoming variable overnight.

&&

.MARINE...
(Tonight through next Thursday)
Issued at 953 PM PST Fri Jan 23 2026

Fresh to locally strong gusts continue across the northern outer
waters tonight before diminishing to a moderate to fresh breeze
early Saturday. Wave heights are currently subsiding across the
coastal waters and will subside below 10 feet by early Saturday.
Improved wind and sea conditions will persist through at least mid
week.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PST Saturday for Pt Arena to Pt
     Reyes 10-60 NM.

&&

$$

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

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