022
FXUS66 KSGX 172149
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
149 PM PST Mon Nov 17 2025
.SYNOPSIS... A weak storm system will move through the area later
today into early Wednesday. This will bring light to moderate rain
showers and accumulating snowfall in the mountains. There will be a
brief lull in the action on Wednesday, with sunnier but continued
cooler weather. Yet another winter storm system will move closer to
the region later on Thursday through at least Friday night, bringing
another round of rainfall and higher elevation snow. Things look to
dry out sometime early next week.

 &&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

An area of low pressure has moved into Northern California, where an
associated frontal boundary continues to move through Southern
California. Light showers have been noted so far from LA to
Ventura. Showers may increase in intensity through the afternoon
and evening hours over our region as hi-res models indicate.
Hourly rain rates will peak around 0.50"/hr, but most rates will
be closer to one quarter of an inch. We are not expecting too many
impacts with this but areas that flooded from the weekend or any
other low lying/poor drainage areas may see localized ponding or
flooding. This system will be colder than the last, so snow levels
near 7,000 feet to start but lower near 5,000 feet by Tuesday
evening. A Winter Weather Advisory has been issued for areas in
the San Bernardino County mountains above 6,000 feet. A general
2-4 inches is expected around this elevation with locally over 5
inches for areas over 7,000 feet through Tuesday evening.

The exact track of this low pressure system is being a bit more
resolved in the models, where the low will move directly over our
area. This will provide a better chance of thunderstorms as the cold
core moves over the region, so areas mainly west of the mountains
will see continued isolated showers and thunderstorms into the day
on Tuesday. There will be intermittent breaks in the clouds west of
the mountains throughout the day with sunnier conditions in the
deserts. Tuesday will be a chillier day as well, with highs 10-20
degrees below average. By Wednesday, the track of this system
starts to diverge in the model guidance. Some show the system
going far enough south, giving us sunnier and drier conditions.
Others show a more interesting scenario, where the backside of the
low will produce more precipitation along the mountains into the
deserts. We will continue to watch this, as this could produce
additional desert rain and mountain snowfall.

The weather pattern continues to remain interesting as we move into
Thursday and Friday. Yet another area of low pressure looks to move
into the Southern California vicinity, where the probability of rain
and mountain snow increases once more. The exact track and
precipitation timing / amount details still somewhat uncertain,
though compared to yesterday, the model guidance is in better
agreement on the system moving over the area or off the coast, which
would give us a wetter weather setup. This will solidify a cooler
and cloudier weather pattern through the work week. High pressure
off the coast looks to move into the region sometime early next week
(Sunday or Monday), where drier and warmer weather will move into
the region.

&&

.AVIATION...
172130Z...FEW-SCT low clouds based 2-5 kft will increase in coverage
this afternoon along with increasing southerly flow. A frontal
precipitation band arrives from the northwest starting in Orange
County around 01-02Z Tue, reaching San Diego by 05-06Z, and pushing
over the mountains and into the low deserts by 09-11Z. Expecting a
few hours of cigs 800-2000 feet MSL and vis 1-4SM through the
coastal basin with the passage of this band. Slight chc (10-15%)
TSRA. Cigs/vis lift and/or scatter out with generally VFR
conditions, thereafter. Higher terrain obscured in FG/RA during
the frontal passage and through the overnight hours. SCT
-SHRA/SHRA begins to develop 12-18Z Tue, reintroducing the threat
for intermittent MVFR cigs/vis through the coastal basin. Slight
chc (10- 15%) TSRA after 18Z.

&&

.MARINE...
A cold front will west to east across the coastal waters from 00-06Z
Tue with a distinct wind shift from south to west-northwest. Wind
gusts behind the front may reach 20-25 knots through 10Z. Check the
Small Craft Advisory for details.

There is a slight chance of thunderstorms this evening along the
cold front, and again Tuesday afternoon. Any thunderstorm could
produce lightning, gusty erratic winds, choppy seas, and/or a
waterspout. No hazardous marine conditions are expected Tuesday
night through Thursday, but the next storm system has the potential
to bring hazardous winds and seas Thursday night and Friday.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Winter Weather Advisory until 10 PM PST Tuesday for San
     Bernardino County Mountains.

PZ...Small Craft Advisory until 2 AM PST Tuesday for Coastal Waters
     from San Mateo Point to the Mexican Border and out to 10 nm-
     Waters from San Mateo Point to the Mexican Border Extending
     10 to 60 nm out including San Clemente Island.


&&

$$

PUBLIC...APR
AVIATION/MARINE...KW