038
FXUS66 KSGX 212228
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
228 PM PST Fri Nov 21 2025

.SYNOPSIS...
Aside from a few stray showers this afternoon, the lull in
unsettled weather ends this evening as wrap around precipitation
fills back in this evening, with additional rain and snow showers
favoring the eastern/southern mountain slopes. Snow levels will
remain near 6500 ft through Saturday morning. Drier weather with a
gradual warming trend sets in for early next week with
temperatures returning above normal by Wednesday/Thursday. There
is the potential for weak Santa Ana winds by the middle of next
week.

&&

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

While there are still a few very scattered showers across the
area, particularly the high deserts this afternoon, the radar is
much quieter now compared to this morning. However, current
satellite and 500mb RAP analysis shows the upper low over the
California Bight, but a vort max diving southward will pull the
closed southward into northern Baja tonight into Saturday. As this
occurs, wrap around precipitation is set to fill back into the
area this evening into the overnight hours, favoring the deserts
and southern/eastern mountain slopes, especially in San Diego
County. This precipitation will generally be light, with rates up
to 0.1-0.2"/hr though localized enhancements, particularly along
the San Diego County desert mountain slopes, are possible.
Additional rainfall totals from this wrap around will be 0.2" or
less for the coasts/valleys, 0.75-1" in the mountains (though
eastern slopes could see additional totals closer to 1.5-1.75"),
and 0.25-0.5" in the deserts. Snow levels remain near 6500ft
through tonight but gradually rise to ~7000ft Saturday afternoon.
Additional snowfall above 6500ft through Saturday morning range
from 2-5", with locally up to 9" on eastern mountain slopes.
Snowfall rates could be 1-1.5"/hr at times and given the expected
additional snowfall, the Winter Storm Warning has been extended
through 10 AM Saturday for mountain elevations in San Bernardino
County and Riverside County >6500ft.

The wrap around precipitation eventually tapers off by Saturday
afternoon as the upper low begins to lift northeastward and dry
northwesterly flow aloft returns for Sunday into Monday.
Temperatures slowly respond with a subtle warming trend that returns
afternoon highs to seasonable norms by Monday/Tuesday. Ensembles are
consistent with a trough digging from the Pacific Northwest through
the Great Basin, aiding to strengthen to the offshore pressure
gradient Tuesday into Wednesday. Currently there is about a 40%
chance of a weak to moderate Santa Ana event mid-next week, likely
peaking around Wednesday. Between the offshore winds and an upper
ridge peaking Thursday, temperatures warm to 5-10 degrees above
normal for Wednesday into Thursday.

Looking into the far extended, ensembles continue to hint on another
storm system late next week that could bring another round of rain.
Significant uncertainty remains in the timing and track of this
next trough, so it`s not something to get too excited about just
yet.

&&

.AVIATION...
212130Z...Coasts/Valleys...BKN low clouds based 3000-5000 ft MSL
will become more SCT this evening through the coastal basin along
with SHRA and associated cig/vis reductions becoming isolated. Light
-RA increasing in coverage again over just San Diego County from 06-
12Z Sat. East to southeast winds gusting 25-35 knots after 00Z in
coastal foothills and locally into inland valleys.

Deserts/Mtns...BKN-OVC low clouds 4000-6000 ft MSL currently. SHRA
will become more persistent and widespread in the low deserts with
MVFR cig/vis reductions at times. Slight chance TSRA in the San
Diego County deserts/mtns 00-06Z Sat. SCT FG/SHRA/SN in the mtns
through Saturday morning, especially along the eastern slopes, where
precip will be favored. Conditions slowly improving after 12Z
everywhere with any precip becoming more SCT and intermittent.

&&

.MARINE...
No hazardous marine conditions are expected through Wednesday.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Winter Storm Warning until 10 AM PST Saturday for Riverside
     County Mountains-San Bernardino County Mountains.

PZ...None.

&&

$$

PUBLIC...Munyan
AVIATION/MARINE...KW