FXUS66 KMTR 180457
AFDMTR
Area Forecast Discussion
National Weather Service San Francisco CA
857 PM PST Mon Nov 17 2025
...New UPDATE...
.KEY MESSAGES...
Updated at 1242 PM PST Mon Nov 17 2025
- Scattered showers and a slight chance of thunderstorms will
gradually decrease through Monday night before drier weather
returns Tuesday.
- Next system brings more beneficial type rain late Wednesday
through Thursday.
&&
.UPDATE...
Issued at 856 PM PST Mon Nov 17 2025
Forecast remains on track tonight, but what a difference 24hrs
makes. We do still have some scattered light showers drifting south
across our area, especially over the water. Despite the drier
conditions tomorrow and Wednesday, temperatures will continue to be
below normal. Tuesday will be mostly sunny, but on Wednesday we'll
see cloud cover gradually increase as the next system makes its way
south toward our area. This next storm will not carry the same punch
that we saw last night. The weekend looks mostly dry, with
deterministic guidance backing off the potential for another round
of rain for the beginning of next week.
&&
.SHORT TERM...
Issued at 1242 PM PST Mon Nov 17 2025
(This evening through Tuesday)
Isolated to scattered rain showers persist over the region this
afternoon with thunderstorms showing up to our east. A surface low
pressure is currently positioned over the North Bay with a mid/upper
level aloft. This will result in increased instability with surface
based and most unstable CAPE forecast to be up to 500 J/kg through
the afternoon. Any heavier rain showers and/or thunderstorms will be
capable of producing 0.25"-0.50" of rainfall per hour, yet these
rates will be isolated in nature. Conditions begin to dry out by
late tonight and more so into Tuesday morning.
Temperatures will generally be in the low-to-upper 40s across the
coldest spots across the region with upper 40s to lower 50s along
the San Francisco Bay Shoreline and the City of San Francisco.
This drying trend will occur as the aforementioned surface and
mid/upper level lows shift southward through the day on Tuesday. A
short-wave ridge will build across the Bay Area and Central Coast
through Tuesday with temperatures warming to near normal across the
Bay Area and North Bay while up to 10 degrees cooler than normal
across the Central Coast. Mostly sunny sky conditions are expected
beyond the morning hours on Tuesday.
&&
.LONG TERM...
Issued at 1242 PM PST Mon Nov 17 2025
(Tuesday night through next Sunday)
Light to occasionally moderate rain returns late Wednesday night
across the North Bay and then increase in coverage and intensity
through Thursday early afternoon across of the remainder of the Bay
Area and Central Coast. This system is forecast to move through
rather quickly producing 0.50"-1.00" in the coastal ranges and
higher elevations across the region, 0.25"-0.33" in the North Bay
Valleys and around San Francisco, and generally less than 0.25"
elsewhere. However, as things become increasingly saturated, the
risk for shallow land/rock/mud slides will also increase.
Friday through the rest of the upcoming weekend look to be dry with
temperatures rebounding closer to seasonal averages. This is
captured by the 6-10 Day Outlooks from the Climate Prediction Center
showing conditions leaning below normal for precipitation and near
normal temperatures.
&&
.AVIATION...
(06Z TAFS)
Issued at 838 PM PST Mon Nov 17 2025
Currently a mixed bag of MVFR-VFR at the terminals. Rain showers
will follow the path of the surface low, sliding south and east
through tomorrow morning. As such, high-end MVFR/low-end VFR with
rain showers in the vicinity can be expected through the night.
Winds will decrease and veer through the night as the effect of
the surface low wanes. Order is restored tomorrow in the form of
dry conditions and diurnal wind patterns.
Vicinity of SFO...Currently MVFR with westerly flow. Low-end
VFR/high-end MVFR with westerly flow and rain showers in the
vicinity will prevail for the next couple of hours. As the surface
low exits to the southeast, rain shower activity will wane and
winds will decrease and back. Diurnal winds return tomorrow
afternoon.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Currently VFR with southerly flow at MRY
and VFR with southwesterly flow at SNS. Low-end VFR/high-end MVFR
with westerly flow and rain showers in the vicinity will prevail
through the night. Winds will decrease and back through the night
with diurnal winds returning tomorrow afternoon.
&&
.MARINE...
(Tonight through next Sunday)
Issued at 838 PM PST Mon Nov 17 2025
A chance for rain showers will continue through the night. While
conditions will slowly begin to improve, rough seas and strong
northerly breezes will persist through Tuesday, especially for the
outer waters. Conditions briefly become non-hazardous Wednesday.
Fresh to strong northerly breezes and rough to very rough seas
return Thursday and persist into Friday.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 PM PST this evening for Mry Bay-SF
Bay N of Bay Bridge.
Small Craft Advisory until 3 AM PST Tuesday for Pigeon Pt to Pt
Pinos 0-10 nm-Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt
Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.
Small Craft Advisory until 3 AM PST Wednesday for Pigeon Pt to
Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM.
&&
$$
SHORT TERM...RGass
LONG TERM....RGass
AVIATION...Sarment
MARINE...Sarment
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Prepared by Boulder-Creek.com Weather at: Tue Nov 18 02:30:03 PST 2025
From the National Weather Service
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