Glen Avon, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

929
FXUS66 KSGX 301624
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
924 AM PDT Fri May 30 2025

.SYNOPSIS...
Several degrees warmer today for inland areas with the greatest
warming for the inland valleys and inland Orange County. A weak
upper level low pressure system off the Baja coast will draw some
tropical moisture northward into the area for the weekend. Some
lighter showers could occur as early as Saturday, but the most
likely time for more widespread showers is for Sunday afternoon
and evening along with a slight chance of thunderstorms. There
will be a cooling trend for Saturday through Tuesday with a deeper
marine layer for early next week. Then dry with warming for
Wednesday and Thursday.

&&

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

.Morning Update...

A 580mb low currently off the coast of Baja California about 150
south of San Diego continues to bring in tropical moisture this
morning. The latest morning sounding from Miramar shows around
0.90" of precipitable water, where areas over 700 mb are becoming
closer to saturation. Hottest temperatures of the next seven days
will occur across much of the region today, where there is a low
to moderate chance of highs in the Inland Empire and far inland
valleys of San Diego County reaching 100 degrees. The wetter
trend in the upper levels of the atmosphere will continue into
the weekend, as low to the south starts to entrain more moisture
from the subtropics. Will continue to look into the forecast
details of this later this afternoon, but as my colleague states
below, Sunday will be the time for the best chance of showers and
thunderstorms across SoCal.

.Previous Discussion...

.SHORT TERM (Today through Sunday)...
A weak upper level low pressure system off the coast of northern
Baja will drift toward the southwest through tonight, then
begin moving toward the northeast late Saturday, moving across
northern Baja late Sunday and into Arizona Sunday night as it
weakens.

High pressure aloft to the north and easterly lower level flow
will bring the greatest warming today to the inland valleys and
inland Orange County. High temperatures will range from the lower
70s near the San Diego County coast to the mid to upper 90s for
the Inland Empire with the lower deserts reaching 100 to 105. A
cooling trend will begin on Saturday and continue through
Tuesday with extensive cloud cover keeping Saturday night warmer.

Some mid level moisture from the tropics will begin to spread into
the area from the south for late tonight and Saturday with a
greater influx for late Saturday night into Sunday. Some lighter
showers or virga could occur as early as Saturday, but the most
likely time for more widespread showers is for Sunday afternoon
and evening along with a slight chance of thunderstorms. the
mountains are most likely area to receive somewhat greater
amounts with NBM probabilities of receiving one-half inch more
of rainfall having increased to 10 to 20 percent.

&&

.LONG TERM (Monday through Thursday)...
A weak lower pressure system from the northwest will move into
southern California for early next week. This will deepen the
marine layer and continue the cooling trend through Tuesday.
Warming will follow for Wednesday and Thursday with Wednesday
high temperatures a few degrees below average and Thursday high
temperatures around average.

&&

.AVIATION...
301600Z...Coasts/Valleys...Low clouds (based 1300-1600ft MSL)
quickly cleared out of San Diego County this morning, but will take
another hour or so to clear from Orange County, with full clearing
by 17z. Low clouds likely rebuild and move back ashore after by 09-
12z, but have a 30-40% chance to bring CIGs to the coastal TAF sites
by 06z. Bases will be 800-1300 ft MSL with only about 5-10 miles on
inland extent by 12-14z. Clouds quickly clear back out by 15-16z
Saturday morning.

Elsewhere...FEW-SCT clouds AOA 20K ft MSL and VFR conditions today
and tonight.

&&

.MARINE...
No hazardous marine conditions are expected today through Tuesday.
Slight chance of showers across the coastal waters Saturday and
Sunday.

&&

.BEACHES...
A long period south swell will build into the region Sunday, leading
to elevated surf for south and southwest facing beaches of 4 to 6
feet with sets to 7 feet possible. This will result in higher rip
current risk and locally hazardous swimming conditions. Surf builds
Sunday, peaks Monday, then gradually diminishes again Tuesday
through Thursday.

&&

.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...Munyan/CSP