449
FXUS66 KMTR 182119
AFDMTR

Area Forecast Discussion
National Weather Service San Francisco CA
119 PM PST Tue Nov 18 2025

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

.KEY MESSAGES...
Updated at 118 PM PST Tue Nov 18 2025

 - Mainly dry weather through Wednesday, with a few isolated showers
   being possible.

 - More beneficial type rain late Wednesday through Thursday.

 - Dry weather returns Friday and continues through the weekend.

&&

.SHORT TERM...
Issued at 118 PM PST Tue Nov 18 2025
(This evening through Wednesday)

Upper level troughing will slowly swing through southern CA today
and tomorrow, while weak upper level ridging quickly builds and then
flattens. Radar thus far has shown a few showers develop over
southern Monterey and San Benito counties, while elsewhere we have a
mix of sunny skies and fair weather cumulus. Tonight, skies should
clear and given the moisture we may see some valley fog. Tomorrow,
deterministic models suggest a weak disturbance passing over head,
which may bring some high clouds and perhaps a few isolated showers
to the region. Otherwise quiet weather prevails until the next
system approaches the PacNW. Rain chances begin to increase for the
North Bay during the evening hours.

&&

.LONG TERM...
Issued at 118 PM PST Tue Nov 18 2025
(Wednesday night through next Monday)

The aforementioned upper level low will bring a round of beneficial
late Wednesday into Thursday. Rainfall amounts continue to be around
0.25" for the North Bay counties, with perhaps slightly higher
amounts in the terrain. Elsewhere, amounts look to anywhere from 0.1-
0.25", with lower amounts expected for interior locations. The Santa
Cruz and Santa Lucia mountains may see slightly higher amount. Once
this system exits the region, ensemble and deterministic models
show upper level ridging building in for the weekend. Given
additional moisture from the rain, we should see some night and
morning fog. The ridge will also bring temperatures up a few degrees
putting most areas near or above normal.

&&

.AVIATION...
(18Z TAFS)
Issued at 1054 AM PST Tue Nov 18 2025

Expect widespread VFR into the afternoon as cloud cover erodes
across the area. Expect light to moderate winds through the evening
before winds reduce into the night. Wind directions look to be
driven by local effects through the day, and winds will be more
variable into the night as they weaken. As a weak low pressure
center moves through the area, causing some southerly to easterly
winds overnight and into Wednesday morning with some spotty lower
CIGs. Slight chances for light rain will also more through the area
into the late morning, but these rains do not look impactful.

Vicinity of SFO...Skies are clearing with easterly winds looking to
turn westerly in the mid afternoon. These winds will weaken into the
night and turn southwesterly as scattered mid-clouds return. Expect
MVFR-level CIGs to return into early Wednesday as winds turn more
southerly, but these CIGs rise into that afternoon as light showers
move through the area and winds become southwesterly again.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Scattered mid-level clouds linger through
the day. Light winds turn more moderate and westerly in the mid
afternoon and last into the night before becoming light and
variable. SNS looks to be affected by moderate drainage winds from
the southeast into early Wednesday.

&&

.MARINE...
(Today through Sunday)
Issued at 1027 AM PST Tue Nov 18 2025

Light showers exit into the afternoon. Expect wave heights remain
elevated and winds remain fresh to strong with near gale force
gusts possible across the northern waters through late Tuesday.
Marine conditions briefly improve Wednesday as wave heights abate
and winds diminish. A weak system will arrive late Wednesday into
Thursday bringing a return of light rain and hazardous marine
conditions. Locally fresh to moderate winds and significant wave
heights between 10 to 15 feet are expected Thursday into the
weekend.

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Small Craft Advisory until 9 PM PST this evening for Pt Arena to
     Pt Reyes 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...KR
LONG TERM....KR
AVIATION...Murdock
MARINE...Murdock

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