Los Alamitos, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

185
FXUS66 KSGX 170506
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
906 PM PST Tue Dec 16 2025

.SYNOPSIS...
For coastal areas, night and morning low clouds and dense fog will
continue through Wednesday. A few degrees of cooling Wednesday
followed by warming with weak offshore flow on Thursday. Onshore
flow and weakening high pressure aloft will spread cooling inland
for Friday through Monday, but high temperatures remain as much as
10 to 15 degrees above average for some inland areas.

&&

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

At 9 PM low clouds and areas of dense fog had developed along the
coast and in the western valleys. Areas of dense fog are expected
overnight into Wednesday morning. The chances of dense fog
developing decreases Thursday and Friday. Three locations broke high
temperature records today, Lake Cuyamaca, Campo, and Borrego. For
more information check out the headline on our weather.gov/sandiego
homepage. Highs Wednesday will be a few degrees cooler than today
for most locations, with warmer conditions returning Thursday.

From Previous Discussion Issued at 2 PM December 16...

Thursday through early next week...

The ridge will continue to build ahead of an approaching major
shortwave trough which will be approaching the region by this
weekend. It will be considerably warmer on Friday as this occurs,
with temperatures running around 20 degrees above average for the
inland valley areas. As the trough continues to advance slowly
eastward, with will help to bring about a cooling trend going into
early next week, with the marine layer beginning to lift with
strengthening onshore flow. Looking a little beyond the forecast,
there is growing confidence with ensemble and deterministic models
alike which show an increasing chance of precipitation across the
region.

&&

.AVIATION...
170330Z...Coast/Western Valleys...Low clouds based 500-800 feet MSL
have pushed to the I-15 corridor in SD County. Clouds start to
develop over coastal and inland Orange County 05-07z. Areas of FG
and VIS below 1/4SM for the coastal highlands; BR and VIS 1-4SM for
lower coastal areas, with periods of VIS 1/4-1SM after 05z. VIS
begins to improve everywhere 16-18z Wed as clouds clear to the coast
17-19z in SD County and 18-20z in Orange County. Patchy SCT-BKN
clouds and VIS 4-6SM in HZ linger at the immediate coast throughout
the day. Patchy low clouds return with slightly lower bases 00-02z
Thu and coastal VIS reductions 0-4SM after 05-07z Thu.


Otherwise...VFR for interior valleys, mountains and deserts through
the period with SCT clouds above 10k feet.

&&

.MARINE...
Areas of fog will redevelop tonight and continue through about 10 AM
Wednesday morning. A Marine Weather Statement contains more details.
Otherwise, no additional hazardous marine conditions are expected
through Sunday.

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Dense Fog Advisory until 10 AM PST Wednesday for Orange County
     Coastal Areas-Orange County Inland Areas-San Diego County
     Coastal Areas.

PZ...None.

&&

$$

PUBLIC...CO/Stewey
AVIATION/MARINE...Westerink