FXUS66 KMTR 140446
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
946 PM PDT Mon Apr 13 2026
...New AVIATION, MARINE...
.KEY MESSAGES...
Updated at 1125 AM PDT Mon Apr 13 2026
- Slightly cooler to near normal temperatures through Thursday
- Periods of gusty winds, especially at higher elevations
Wednesday through Friday
- Warmer temperatures return Friday and Saturday before unsettled
weather returns for early next week
&&
.SHORT TERM...
Issued at 1125 AM PDT Mon Apr 13 2026
(This afternoon through Tuesday)
Lingering rain showers persist over the Pacific late this morning
with these forecast to diminish through the afternoon and evening.
The RRFS (rapid refresh forecast system) and other CAMs (convection-
allowing models) indicate the potential for isolated rain showers
across the higher terrain of the southern Diablo Range and Santa
Lucia Range this afternoon, diminishing as the sunsets. Otherwise,
mostly dry conditions return to the region this afternoon with
afternoon temperatures forecast to be in the upper 50s to low 60s
near the coast and low-to-upper 60s across the interior. However,
the highest peaks may not reach much above the upper 40s to low 50s.
Tonight, temperatures will be chilly across the interior North Bay
Valleys and interior Central Coast with mid-to-upper 30s expected.
There is a low end potential for frost, yet widespread coverage in
not currently anticipated. Elsewhere, temperatures will range from
the low 40s to near 50 degrees F (warmest near the coast).
For Tuesday, expecting dry conditions with temperatures warming
regionwide by a few degrees as a shortwave ridge builds in wake of
the exiting trough.
&&
.LONG TERM...
Issued at 1125 AM PDT Mon Apr 13 2026
(Tuesday night through next Sunday)
Additional warming is expected on Wednesday, but only again by a few
degrees. All of this is ahead of an approaching frontal boundary
that is forecast to be mostly dry. However, there are chances across
far northern Napa and Sonoma counties Wednesday afternoon and
evening, generally less than 25%. This said, there very well may be
light precipitation as far south as the Central Coast as the front
moves across the region late Wednesday evening and into early
Thursday morning. Little to no measurable rainfall expected with
this system.
In wake of this system, offshore winds are forecast to be strongest
across the North Bay Mountains and East Bay hills Thursday and into
Friday. This will be as the exiting system shifts into the Great
Basin and/or Intermountain West. There still is some uncertainty
with the exact track of this system, thus less confidence in the
strength of offshore winds. However, widespread wetting rainfall
across the region has greatly reduced fire weather concerns (at
least in the short term).
Weak ridging will build in behind the aforementioned system on
Friday and Saturday with temperatures returning to near seasonal
averages along with dry weather. Unsettled weather looks to return
late Saturday and into early next week as another mid/upper level
trough drops out of the Gulf of Alaska and approaches the West
Coast.
&&
.AVIATION...
(06Z TAFS)
Issued at 935 PM PDT Mon Apr 13 2026
A deep marine layer is trying to reform as the atmosphere
re-stabilizes. The most likely impacts will be patchy MVFR
stratus at coastal terminals, although there is a decent chance
for brief impacts at inland terminals as well. There is very
little chance of IFR conditions, however.
Vicinity of SFO...Strong onshore wind will continue through the
night and through the remainder of the TAF period. There is a
20-30% chance of MVFR ceilings between 12Z and 18Z Tuesday
morning before skies clear in the late morning.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...MVFR ceilings rolled in earlier than
expected at MRY, and will very likely remain through mid morning
at least. The bigger question is if and when they reach SNS. The
most likely window is from 10Z to 17Z, before the cloud deck
starts to mix out.
&&
.MARINE...
(Tonight through next Sunday)
Issued at 935 PM PDT Mon Apr 13 2026
The gradient between high pressure in the East Pacific and lower
pressure over California will support a moderate to fresh NW
breeze and moderate seas across the exposed coastal waters
through Wednesday. A cold front will increase winds to near gale
force late Wednesday or early Thursday, building rough seas.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 3 AM PDT Wednesday for Pt Arena to Pt
Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory until 3 AM PDT Tuesday for Pt Reyes to
Pigeon Pt 0-10 nm.
Small Craft Advisory from 3 PM Tuesday to 3 AM PDT Wednesday for
Pt Pinos to Pt Piedras Blancas 0-10 nm.
&&
$$
SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Flynn
MARINE...Flynn
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Prepared by Boulder-Creek.com Weather at: Mon Apr 13 22:30:03 PDT 2026
From the National Weather Service
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