511
FXUS66 KSGX 191744
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
944 AM 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 6000ft. 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...

.UPDATE...
A few showers continue off the coast of Oceanside with some bubbling
cu along the mountain spines stretching from San Bernardino down to
San Diego. While today will be the driest day thus far in terms of
widespread precipitation, localized rain/snow showers will be
possible through this afternoon, generally over the highest peaks of
the mountains. Less moisture today will help limit accumulations,
although the highest peaks could see an additional inch or two with
snow levels holding around 6000-6500ft. For more populous areas
such as Big Bear, generally light mix of rain/snow can be expected
through the afternoon, with rain accumulations of less than a
tenth of an inch. Any lingering precipitation should taper off
this evening, with drier conditions prevailing into Thursday
morning. The next system arrives Thursday afternoon with
additional rain and periods of heavy snow into Friday.

.PREVIOUS DISCUSSION FROM 430 AM...
.SHORT TERM (Today through Friday)...
The slow-moving low pressure system centered over the southern
California bight will begin to accelerate to the east later today
and tonight as the next low pressure system from the northwest
nears the West Coast by early Thursday morning. Some showers have
continued over the coastal waters overnight, the result of
instability from the cold air aloft over the relatively warm sea
surface temperatures. These showers will continue into this
morning. There is also a slight chance of showers for this
afternoon, mainly over the mountains.

Some showers may develop late tonight over the inner coastal
waters and spread inland into coastal areas for late tonight into
Thursday morning. Some light showers from the next low pressure
system may begin to spread into portions of southwestern
California during the day on Thursday with more widespread showers
along with a slight chance of thunderstorms spreading into the
area on Thursday night with showers continuing into Friday.

The snow level will rise to around 7000 for late Thursday
afternoon, then fall to around 6000 for early Friday morning,
before rising to around 6500 feet for Friday evening. Rainfall
could range from around one-half inch near the coast to 1 to 2
inches for the mountains. Chances for one inch or more of rainfall
or liquid-equivalent above the snow level through Friday night
ranges from around 25 percent near the coast to 45 to 55 percent
in the mountains.

The NBM deterministic snowfall for Big Bear of just under 10
inches is near the 60th percentile of the distribution. A Winter
Storm Watch for mountain elevations above 6000 or 6500 feet may be
needed for Thursday night into Friday.

&&

.LONG TERM...
There remain model differences in the placement and movement of
the closed upper level low pressure system for the weekend
impacting whether and where some showers might linger into the
weekend. For next week, drier and warmer weather is expected with
high temperatures on Tuesday and Wednesday within a few degrees of
average.

&&

.AVIATION...
191700Z...Primarily VFR conditions through the period. Building
cumulus around 9000 feet mainly over mountains, with SHRA 19-02Z.
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.

&&

.MARINE...
No hazardous marine conditions are expected through Thursday.
Southerly winds will increase late Thursday ahead of the next storm
system. Winds may briefly turn easterly before becoming westerly by
early Friday after the front passes. 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...None.
PZ...None.

&&

$$

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