Lake Forest, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

864
FXUS66 KSGX 211549
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
849 AM PDT Sat Jun 21 2025

.SYNOPSIS...
Gusty westerly winds over the mountains and into the deserts today
with cooler conditions and a more extensive marine layer low cloud
coverage. Below average temperatures will continue early in the
week, with a gradual warming for the middle to end of the week. The
marine layer will become shallower for the middle to end of the
upcoming week.

&&

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

At 8:30 AM, visible satellite was showing extensive low cloud
coverage from the beaches to the mountain slopes, locally into
mountain passes. Low clouds are expected to gradually clear inland
areas, but may linger along the immediate coast into the afternoon
hours. High temperatures today are expected to be 3 to 7 degrees
cooler than yesterday for most locations, up to 10 degrees cooler
than yesterday in the High Desert. An upper level low passing
through the Great Basin will increase the onshore pressure gradient.
That will result in additional rounds of gusty westerly winds over
the mountains and into the deserts this afternoon and evening. Winds
will be strongest through the San Gorgonio Pass where gusts 55 to 60
mph are possible, otherwise gusts will be 35 to 50 mph.

For early in the upcoming week, a long wave troughing pattern will
remain over the Western United States. That will keep high
temperatures 5 to 10 degrees below average through Tuesday. Even
remaining below average, temperatures between today and Sunday are
expected to increase 3 to 7 degrees. A brief period of offshore
winds can be expected Sunday morning on the coastal mountain slopes,
with minimal impact expected. Marine layer low clouds and fog are
expected each night and morning and will reach into the valleys.

For Wednesday through the end of the upcoming week, the upper level
troughing shifts north, allowing for weak ridging to build in. That
will bring a gradual warming. Current forecast for the end of the
week follows NBM with highs within a few degrees of normal. The
increased ridging will result in a shallower mariner layer, with
persistent coverage along the coast and less coverage expected in
the valleys.

&&

.AVIATION...
211530Z....Coast/Valleys...Low clouds based 2500-3500 ft MSL will
slowly clear for inland areas 16-18z. VIS 1-5SM where clouds and
terrain intersect, obscuring higher terrain. FEW-SCT low clouds
expected to linger this afternoon within a few miles of the SD
County coast; 20% chance for BKN cover at times. BKN low clouds
surge back 00-03z for SD County coast and valleys. Clouds will
likely spread into Orange County and through the Inland Empire as
seen this morning, though there is less confidence in full coverage
of clouds that far north compared to this morning. Regardless, bases
will likely be similar to this morning, around 2000-3000ft MSL.

.Mountains/Deserts...Clear skies and unrestricted VIS through
early Sunday morning. Strong westerly winds occurring, with gusts 30-
50 knots by 18-21z this afternoon for mountain passes and locally
into deserts. These gusts are likely to produce pockets of
up/downdrafts in lee of mountains/mountain passes in addition to
isold BLDU in the desert with VIS 3-5SM at times. Winds gradually
weaken tonight into Sunday morning.

&&

.MARINE...
Aside from northwesterly wind gusts near 20 kts in the vicinity of
San Clemente Island this afternoon, no hazardous marine conditions
are expected through Wednesday.

&&

.BEACHES...
Elevated surf this afternoon, 3-5 feet sets to 6 feet for west
facing beaches.

&&

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


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory until 11 PM PDT this evening for Apple and Lucerne
     Valleys-San Diego County Deserts-San Gorgonio Pass near
     Banning.

PZ...None.

&&

$$

PUBLIC...CO
AVIATION/MARINE/BEACHES...Westerink