114
FXUS66 KSGX 192206
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
206 PM PST Wed Nov 19 2025

.SYNOPSIS...
Light rain/snow showers over the highest points of the mountains
today before drier weather tonight into Thursday morning. The next
system arrives Thursday, delivering heavy rainfall late Thursday
night into Friday afternoon. Up to an inch of rainfall possible
for coast/valleys, higher in the foothills and lower elevations of
the mountains. Periods of heavy snowfall for the higher terrain,
especially early Friday morning, with snow levels around or just
above 6500ft. The slow moving system will allow precipitation to
linger into Saturday. Drier weather with a very slow warming trend
sets in for the end of the weekend into early next week, warming
to near normal by Wednesday.

&&

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

Satellite shows bubbling cu over much of the region as a cutoff low
shifts eastward into Arizona this afternoon. A few lingering light
rain and snow showers will be possible across the San Bernardino and
Riverside mountains through this evening, with very limited
additional accumulations expected due to lessening moisture in the
mid levels. Outside of these locations, dry weather will prevail
with chilly temperatures due to the exiting low. Highs both today
and tomorrow will be well below seasonable averages by around 10-20
degrees, generally in the 50s and 60s.

The next system to arrive will be a trough over the PacNW that is
pinched and becomes cutoff, rapidly advancing southward along the
coast. This low, similar to the last system, will situate right off
the coast of Southern California Thursday/Friday before moving
inland Saturday. There will be less moisture with this upcoming low
compared to the system this past weekend, but we are still looking
at widespread wetting rainfall for the end of the week. Rain will
begin as early as Thursday morning, increasing Thursday night and
Friday morning, with an associated thunderstorm threat during this
time period. Rain may continue for much of the day Friday as the low
moves into position, with increasing winds over the marine waters
and the higher elevations. This system looks to only produce
moderate winds with limited gradient tightening and the core of the
system a bit too far south. Still, gusts in the deserts, mountains,
and marine waters could reach up to 30 mph at times on Friday, with
even gustier and erratic winds in any thunderstorm. The thunderstorm
threat lessens Friday afternoon, with only light to moderate rain
showers prevailing into Saturday.

700 mb temperatures remain extremely cold, attributing to our
inability to warm much in between systems. The snow level for the
beginning of this event looks to hover right around 6000ft,
raising a bit to 6500ft Thursday night into early Friday morning
coinciding with the timing of the heaviest precipitation. With
snow levels rising, elevations between 5500-6500ft will see a
mixture of snow/rain, transitioning to more rain by Friday
morning. Periods of rain with rates greater 0.50"/hr will fall on
already highly saturated soils, which may cause moderate flooding
on and around recent burn scars. Always monitor the forecast and
listen to local emergency officials. Above the snow level,
snowfall rates could reach 1"+/hr, primarily in the early Friday
morning time frame. Snowfall totals Thursday through Saturday of
5-10 inches for elevations 6500-7500ft, with up to 16 inches for
the highest peaks. A Winter Storm Watch is in effect for
elevations above 6500ft for this period, and heavy snow in the
early morning hours of Friday may make travel hazardous. Avoid
travel during this time if possible, especially along Hwy 38 near
Big Bear. If you must travel, ensure you have emergency supplies
in your car and have a way to contact emergency services in low
cell coverage areas.

This system will follow a similar path to the cutoff low exiting
today, moving into Arizona Saturday into early Sunday. As this
system moves across, wrap around moisture will result in lingering
light rain and snow showers across the region, best chances in
San Diego and Riverside counties. High uncertainty remains on
timing and accumulations Saturday due to the model spread in the
movement of the low, fairly unusual to have such limited agreement
72 hours out. Snow levels will remain around 6500ft on Saturday,
rising closer to 7000ft by early Sunday. As the last of the
precipitation moves out, a slow warming and drying trend will
settle in for the remainder of the forecast period. Highs may
return to near normal by Tuesday/Wednesday as weak ridging
develops overhead, and dry weather prevails after Sunday.

&&

.AVIATION...
192130Z...Primarily VFR conditions through 18Z Thursday. SCT-BKN
cumulus based 8-10 kft MSL and SHRA over the mountains through 02Z
Thu. Increasing clouds around 2500-4000 feet MSL in coast and valley
areas after 06Z Thu with SCT -SHRA after 12Z for San Diego/Orange
County coasts and valleys ahead of the next storm system.

Increasing south to southwest winds after 18Z Thu along with
widespread RA/SHRA moving in from northwest to southeast, reaching
KSAN 21-00Z. Widespread MVFR cig/vis reductions expected for the
coasts and valleys after onset of SHRA, with the mountains becoming
shrouded in FG.

&&

.MARINE...
No hazardous marine conditions are expected through Thursday.
Southerly winds will increase late Thursday ahead of the next storm
system. Moderate confidence in winds turning westerly and
strengthening by early Friday as the front passes, but exact track
of the low pressure system may create large differences in both wind
speed and direction Thursday evening through Friday. Gusty winds and
choppy seas may create hazardous conditions for small craft. There
is also a slight chance of thunderstorms late Thursday through late
Friday. Any thunderstorm could bring lightning, gusty winds, choppy
seas, and a waterspout.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Winter Storm Watch from Thursday morning through Saturday
     morning for Riverside County Mountains-San Bernardino
     County Mountains.

PZ...None.

&&

$$

PUBLIC...Zuber
AVIATION/MARINE...KW