720
FXUS66 KSGX 101722
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
922 AM PST Mon Nov 10 2025

.SYNOPSIS...
Warm conditions expected today with periods of weak to locally
moderate northeast to east winds. Patchy dense fog is expected
for the coast and western valleys tonight into Tuesday morning.
Cooler conditions expected for the middle to end of next week. A
windy and wet pattern is expected for the end of the week.

&&

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

Areas of fog and dense fog were observed this morning within about
15 miles of the coast. As of 9 AM, visibility had improved rather
significantly with just a few patches of low clouds lingering along
the immediate coast. Areas of dense fog are possible again tonight
into Tuesday morning from the coast into portions of the western
valleys. The most likely locations for dense fog will be on the
coastal mesas and near higher coastal terrain.

An area of low pressure currently 1400 miles west of San Diego will
slowly begin to move east today. This slow eastward progression
will begin to weaken the ridge of high pressure over the area by
Tuesday. As the upper level pattern begins to shift, the surface
offshore pressure gradient will weaken and begin to transition
back onshore. Northeast to easterly winds this morning peaked at
30 to 40 mph. Winds will continue to weaken through the morning.
With influence from the offshore flow and a fairly robust high
pressure aloft high temperatures west of the mountains will be a
few degrees warmer than yesterday. As the high weakens, conditions
will begin to cool for Tuesday. Highs Tuesday will be 3 to 5
degrees cooler than today west of the mountains. Cooler conditions
will continue to spread further inland Wednesday. As the onshore
pressure gradient continues to increase for the middle of the
week, dense fog will become less likely for coastal locations.

There is becoming better agreement in model guidance for the
incoming low pressure system, particularly when it comes to the
onset of the precipitation. Most guidance is indicating that
precipitation will begin as early as Thursday afternoon and evening
with decreasing chances for showers for Friday and Friday night.
Through Friday, NBM has a 70 to 90 percent chance for one-quarter
inch or more of rainfall from the coast to the mountains with a 25
to 45 percent chance of 2 inches or more for the mountains. Snow
levels above 10000 feet will lower to 5500 to 6500 feet for Friday
morning through Friday night. For early Friday, the NBM 25th
percentile snow level is 4500 to 5500 feet with the 75th percentile
snow level 6000 to 7000 feet. NBM for Big Bear has a 42 percent
chance for 1 inch or more of snowfall and a 9 percent chance for 6
inches or more. Winds are also expected to increase for Thursday
into Friday. Gusts of at least 40 to 50 mph are looking likely over
the mountains and into the deserts, with the potential for wind
speeds to increase as we get closer.

NBM chances for precipitation are slow to taper off into Saturday,
but any rainfall that lingers will likely be more scattered in
coverage. Dry conditions are expected by Sunday, with high
temperatures remaining around 5 degrees below average.

&&

.AVIATION...
101630Z...Coasts/western Valleys...VFR over land areas today but low
clouds and FG will linger over nearshore waters through this
afternoon. Clouds based 400-800 ft MSL return to coastal San Diego
County 00-03Z, expanding later to include Orange County and pushing
up to 10 miles inland. Bases may lower some overnight. Expecting
dense FG (1/4 SM) along elevated coastal terrain and in western
valleys with lesser vis reductions (1-3 SM) at sea level. However,
patches of dense FG will remain possible at sea level. Clouds and FG
retreat to the coastline 15-17Z Tue.

Inland Valleys/Mountains/Deserts...Clear skies and VFR conditions
through Tuesday morning. Localized east to northeast winds 20-30
knots through passes and coastal slopes through 20Z.

&&

.MARINE...
Patches of low clouds and fog may linger over outer coastal waters
this afternoon. FG expands in coverage once again this evening with
areas of visibility less than 1 nautical mile through late Tuesday
morning. A storm system is expected to bring stronger winds and
higher seas for late Thursday through Friday. There is also a slight
chance of thunderstorms Thursday evening.

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...None.

&&

$$

PUBLIC...CO
AVIATION/MARINE...KW