413
FXUS66 KSGX 012014
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
114 PM PDT Wed Oct 1 2025

.SYNOPSIS...
A trough will move into the West Coast, bringing below normal
temperatures and breezy west winds across the mountains and the
deserts by Thursday and Friday. The troughing pattern will stick
around into the weekend and early next week with less wind and
cooler than normal temperatures. Low clouds will also become more
extensive west of the mountains each night into later in the week
as well. A subtle warming trend is slated for the middle of next
week.

&&

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

Crystal clear skies are seen across SoCal this afternoon. A
troughing pattern is present over the West Coast as a large area
of low pressure looms off of the coast of the Pacific Northwest.
This trough will elongate further south over our region by
Thursday into Friday. Similar temperatures will be expected
tomorrow, though west winds will increase slightly over desert
facing mountain passes near 20-35 MPH as the marine layer begins
to build with low clouds more prevalent across the coastal areas.
The main axis of the trough will pass through our region by
Friday, bringing cooler weather and windier conditions the desert
facing slopes into the deserts. Latest model guidance points to
widespread winds 30-45 MPH by Friday afternoon and night, locally
over 50 MPH in the San Gorgonio Pass. High temperatures by Friday
will be generally 5 to 10 degrees below normal with highs 70-80
from the coast into the foothills and high desert.

Model guidance remains in good agreement of the trough departing
and a secondary weaker trough moving into its place over the
weekend. Since the gradient will relax, winds across inland areas
will be lighter. High temperatures will remain similar to that of
Friday with cooler than normal readings with highs in the upper
80s to near 90 degrees in the lower deserts. The trough over the
area will slowly weaken, which will lead to subtle warming across
the region into the middle next week with highs closer to normal.

&&

.AVIATION...
012015Z....Coast...Mostly clear skies and VFR. Areas of low clouds
based around 1000-1500 feet MSL to gradually develop after 02Z this
evening. While initially patchy, there is good confidence for
increasing coverage throughout the night, mainly after 10z, across
the coastal basin. Low confidence (20-30% chance) for patchy VIS
reductions in valleys near I-15 and I-215 due to BR/HZ/FG, likely
timing 11-15z. Scatter out everywhere between 15-17z Thu.

Valleys/Mountains/Deserts...Mostly clear and VFR conditions through
Thursday morning.

&&

.MARINE...
Northwest winds Friday afternoon over outer waters near San Clemente
Island will be sustained near 20 kts. Strong winds will cause for
dangerous conditions for small craft. No other 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...None.
PZ...None.

&&

$$

PUBLIC...APR
AVIATION/MARINE...Westerink

NWS Tucson (SGX) Office