King, California Weather Forecast Discussion

750
FXUS66 KSGX 060406
AFDSGX
Area Forecast Discussion
National Weather Service San Diego CA
906 PM PDT Fri Sep 5 2025
.SYNOPSIS...
Near normal temperatures will prevail through the weekend as
monsoonal moisture slowly lessens over the region. By Sunday, there
will be minimal chances for thunderstorms across the mountains into
next week as a trough of low pressure moves closer to the region.
This system will bring a cooling trend with breezier weather across
the mountains and deserts with a deeper marine layer west of the
mountains.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
A few isolated thunderstorms developed over the San Diego and
Riverside mountains this afternoon, but all activity has diminished
across our area of responsibility. A few patches of low clouds have
made it to the coast as of 9 PM. Low clouds are expected to become
more widespread along the coast overnight.
From previous discussion issued at 2 PM September 5, 2025...
A stronger area of low pressure will move closer to the West Coast
this weekend, bringing a cooling and drying influence over the
region. By Saturday, this drying effect will be felt as monsoonal
moisture and instability begin to lower. This will still provide
enough forcing for one more day of a significant chance of storms,
primarily across the Riverside/San Diego Co mountains. Storms will
be weaker and more isolated in nature.
Areas west of the mountains will see a fairly unchanged weather
pattern through the weekend with high temperatures similar to those
of today. Everyone across SoCal will also start to feel lesser
amounts of humidity as get into the weekend as well. This is all
thanks to an area of low pressure that will move across the state by
early next week. As it does so, we can expect temperatures to cool
through the middle of the week with highs 5 to 15 degrees below
average. There is high confidence in forecast high temperatures by
Wednesday will be in the 70s/80s for many west of the mountains into
the high desert with 90s in the lower deserts. Ensemble model
guidance is in good agreement of this trough sticking around into
later in the week, which would continue the cooler and drier weather
pattern.
&&
.AVIATION...
060335Z...Coast...Low clouds based 1000-1400 ft MSL have formed over
northern San Diego County coastal regions, and will continue to
spread along the coast and inland to 10-15 miles. Reduced vis over
coastal high lands and higher west valley terrain 2-5 SM. Clouds
clearing to the beaches 15-17Z, with VFR conditions following
through late Sat.
Valleys/Mountains/Deserts...Low chances (10-20%) for SHRA over
mountains (mostly mountains of San Diego and southern Riverside
counties) with about a 5-10% chance for isolated TSRA, highest over
southern San Diego Co mtns. Showers/storms possible Sat 20Z-01Z,
with CB bases around 10K ft and any TSRA tops to 35K ft. Any TSRA
will bring gusty, erratic winds, blowing dust with low visibility,
lightning, and lower bases 6000-9000 feet MSL
&&
.MARINE...
No hazardous marine conditions are expected through Tuesday.
&&
.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/APR
AVIATION/MARINE...CSP

NWS SGX Office Area Forecast Discussion