FXUS66 KMTR 291123
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
423 AM PDT Wed Apr 29 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1257 AM PDT Wed Apr 29 2026
- Overnight and early morning stratus returns to the forecast
- Warming and drying trend continues into the late week for
areas away from the coast
- Cooler conditions return this weekend with a chance of drizzle
and/or light rain into early next week
&&
.SHORT TERM...
Issued at 1257 AM PDT Wed Apr 29 2026
(Today and tonight)
Coastal Stratus is building along the SF Peninsula and around Point
Reyes. This cloud cover will be spotty along the coast, will build
further into the night, affecting the bays. This is a good indicator
that the marine layer is becoming more stable, and looks to stay
intact despite the ridging pattern to the north. A big player in
retaining the marine layer is the cut off low to the south west
which will prevent too much of a climb in pressure and keep the
marine zones and immediate coast on the breezier side.
While the marine influence will keep coastal and slightly inland
temperatures fairly stable over the next few days, areas further
inland will continue the warming trend. Wednesday offers highs in
the 60s along the coast, areas inland into the mid to upper 70s and
a few spots breaking 80. This looks to be a slight decrease from
previous model runs, as the ridge to the north seems to have
slightly weekend in the forecast update.
Overnight lows will also see the opportunity to warm, but strong
humidity recoveries and increasing marine influence will make the
overnight warming trend much more modest.
&&
.LONG TERM...
Issued at 1257 AM PDT Wed Apr 29 2026
(Thursday through Tuesday)
The warming trend continues Thursday and Friday. For areas in the
North Bay and potions of the rest of the SF Bay will see fairly
similar temperatures on both days with the warmest interior
locations breaking into the lowers 80s. The bigger difference will
be felt in the interior south bay and the more interior portions of
Monterey and San Benito counties: going from the lower 80s on
Thursday to the mid to upper 80s for Friday.
The trend breaks on friday as the ridge pushes east and weakens.
High-level clouds build through Saturday as a low pressure and
trough builds along the Pacific coast. This low will also call for
expanding the marine layer both in height and inland push, and along
with increasing onshore flow, will allow for a strong cooling trend
through the weekend.
Models are in better agreement for good rain chances, but not a lot
in accumulation from this low pressure moving inland. Drizzly
conditions look to start Sunday morning with the chances for passing
light showers building into that night and lasting into the work
week. Models still need to iron out the finer details of the exit of
this low, but there is good agreement that rain conditions could
last into next Tuesday, before another ridge and warming trend
begin.
&&
.AVIATION...
(12Z TAFS)
Issued at 423 AM PDT Wed Apr 29 2026
Shallow stratus is spreading along the coast and into portions of
the Bay Area. This will bring local MVFR to IFR conditions with the
potential for fog to develop across the North Bay Valleys. Clearing
looks to occur by 17/18Z with stratus returning again tonight as a
relatively deep marine layer persists. Breezy onshore winds return
during the afternoon/evening before winds ease again overnight.
Moderate confidence in timing of stratus return for tonight. Kept a
later arrival (07-12Z) for most sites to stay in line with LAMP
guidance but some models suggest an earlier arrival is possible.
Vicinity of SFO...Patchy stratus is drifting through the San Bruno
Gap producing temporary MVFR CIGs at SFO. Moderate confidence that
MVFR CIGs will fill in at SFO over the next hour and then persist
through late morning. Gusty winds return this afternoon with gusts
peaking around 24-25 knots. Stratus returns late this evening. The
TAF currently has stratus returning around 07Z but LAMP guidance
suggests it could occur closer to 09Z.
SFO Bridge Approach...VFR this morning. Stratus is not expected to
fill in over the SF Bay this morning but models do show stratus
filling in over the bay tonight as a deeper marine layer develops.
Monterey Bay Terminals...Currently VFR with some potential for LIFR
conditions to return later this morning. Up until the last hour, MRY
was reporting stratus and LIFR conditions. Satellite shows an eddy
developing over the bay that pulled stratus away from land. Guidance
shows a decent chance for stratus to return to MRY so have kept in a
tempo for them but removed stratus chances from SNS. Breezy
afternoon winds return before easing overnight. Stratus is expected
to return again tonight with moderate confidence in the current
timing. Current thinking is that more widespread stratus will return
earlier tonight given the expected deeper marine layer.
&&
.MARINE...
(Today through Monday)
Issued at 423 AM PDT Wed Apr 29 2026
Breezy, fresh to strong northerly winds continue to bring locally
hazardous conditions for small crafts into the weekend.
Significant wave heights, driven by the stronger winds, build late
week into the weekend with fresh swell between 8 to 12 feet
expected. Winds diminish and seas abate late weekend into next
week.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory from 3 PM this afternoon to 3 AM PDT
Thursday for Pigeon Pt to Pt Pinos 0-10 nm-Pt Arena to Pt
Reyes 0-10 nm.
Small Craft Advisory from 3 PM this afternoon to 3 PM PDT
Thursday 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 Thursday for Pt Arena to Pt
Reyes 10-60 NM.
&&
$$
SHORT TERM...Murdock
LONG TERM....Murdock
AVIATION...Kennedy
MARINE...Kennedy
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Prepared by Boulder-Creek.com Weather at: Wed Apr 29 06:30:05 PDT 2026
From the National Weather Service
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