Lake San Marcos, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

799
FXUS66 KSGX 241101
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
301 AM PST Sat Jan 24 2026

.SYNOPSIS...
Isolated light showers will continue into Saturday for the
mountains westward. Dry weather with a gradual warming trend is
expected for Sunday through Friday. Weak to locally moderate
Santa Ana winds develop for late Saturday night through Monday
afternoon mostly gusting to 45 mph or less. Weaker offshore flow
will persist Tuesday and Wednesday. Lower confidence in the
weather pattern late in the week with some ensemble members
showing precipitation, though the majority remain warm and dry.

&&

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

This weekend...

A longwave trough located over the entire CONUS is allowing for
another upper level low to drop down over California throughout the
day, and then pass to the south as it propagates eastward and opens
back up to become absorbed back into the trough. As there still
remains to be a decent amount of saturation in the lower levels up
to the 700 mb level, the added lift will allow for the cooler
temperatures to persist, and also allow for there to be a slight
chance of light rain and/or drizzle to be possible this morning,
especially for the foothills of San Diego and Orange counties. There
could also be some patchy areas of fog for some of the coastal and
inland locations. By later in the day, snow levels will continue to
drop to around 5500-6500 ft due to colder air advection from the
north, which may allow for a dusting of snow later this evening for
Mt Laguna, and the surrounding areas. This trough will also allow
for the surface pressure gradient to tighten and bring about some
stronger and gusty winds across the higher terrain by later this
afternoon, and then weaken overnight into tomorrow, with gusts up to
around 45-50 mph possible along some of the foothills and through
the passes. Drier conditions will also set in tomorrow as the
trough begins to flatten and shift further eastward. Winds will
continue to turn more easterly tomorrow weak downsloping offshore
winds will result in high temperatures being about 3 to 5 degrees
warmer from where they will be today.

Monday through Friday...

Drier conditions and a gradual warming trend will occur from the
beginning through mid part of next week as a positivitely-tilted
ridge begins to build in over the Great Basin. Some of the
deterministic models are hinting at the probability of an area of
low pressure possibly influencing the region towards the end of the
week, although this is still quite far out in the forecast period,
and therefore is subject to change. The marine layer will likely
struggle to reform overnight and move inland during the early part
of next week with weak offshore winds, although once the winds
switch back to being onshore by later in the week, the marine layer
will also become subsequently more persistent through the early
morning hours.

&&

.AVIATION...
241030Z....Coasts/Valleys...Iso -SHRA possible through 19Z this
morning for coast/western valleys, bringing occasional vis 5-6 SM.
Low clouds covering coastal basin this morning with varying bases
1500-4500 ft MSL. Conditions expected to continue to vary between
MVFR and VFR, with occasional local IFR in inland valleys. Low
clouds then rise above 3000 ft MSL by 17-19Z and gradually scatter
out over the afternoon, lingering longest in inland valleys.
Offshore north to east flow develops this afternoon and strengthens
late this evening, bringing gusts 20-45 mph for the foothills
locally into valleys and likely preventing any low clouds from
redeveloping/impacting any TAF sites through Sun morning. Local
areas LLWS into the IE possible after 03Z Sun.

.Mountains/Deserts...FEW-SCT clouds around 10,000ft MSL and VFR
conditions expected through the period. Local areas BLDU possible
late Saturday night into Sunday morning with gustier easterly winds,
and local wind gusts 30-50 mph through mtn passes. Mod up/downdrafts
near the mountains after 03Z Sun.

&&

.MARINE...
No hazardous marine conditions are expected through Wednesday.

&&

.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...Stewey
AVIATION/MARINE...CSP