Helendale, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

938
FXUS66 KSGX 270402
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
902 PM PDT Sat Jul 26 2025

.SYNOPSIS...
A trough across the West Coast will continue cooler than normal
weather through the weekend. High pressure will expand further
west, bringing a warming trend Sunday into Tuesday, with
temperatures staying near average through the end of next week.
Breezy west winds will continue this weekend across mountains and
deserts, while the marine layer provides low clouds at times west
of the mountains.

&&

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

A few high clouds continue to lift northeast across the region
this evening, and low clouds are developing off the coast. The 00Z
KNKX sounding shows the marine inversion based near 2300 ft MSL,
deep enough to allow low clouds to spread into parts of the inland
valleys overnight.

Upper level high pressure over the southeast US will slowly shift
westward and expand into SoCal through midweek, then the upper
level pattern remains fairly stagnant through the end of the week
with the high centered somewhere near TX and weak troughing along
the West Coast. This will bring gradual warming through Wednesday
with little day-to-day variation into next weekend. On Sunday, high
temperatures will be around 7-12 degrees below normal in the
mountains and valleys, and around 3-5 degrees below normal near
the coast and deserts. By Wednesday highs will return to near
normal, or around the mid 70s to low 80s for the coastal areas,
mid 80s to mid 90s in the valleys, 70s and 80s in the mountains,
90s to around 100 in the high desert, and 105-110 in the low
deserts. With the trough still in the vicinity and southwest flow
aloft prevailing, ensembles remain predominantly dry through the
end of the week. A few members from the EPS and GEFS have an
increase in Precipitable Water as monsoon moisture tries to sneak
in, but they are very much in the minority. At this point the
chance of moisture returning is less than 5% for the rest of the
week. And in case you thought this may mean we are free from No
Sky July, marine low clouds will hold on through the week, though
clouds will become confined to the coastal areas as the marine
layer becomes more shallow.

&&

.AVIATION...
270300Z....Coasts/Valleys...Low clouds based 1800-2300 ft MSL are
slowly developing over coastal waters. Clouds will overtake San
Diego County in the next few hours. Slowly filling into Orange
County around 09z and most of the Inland Empire by 12z.
Scattering to the coast by 17-18Z. Clouds return to coastal areas
after 03z with lower bases 1200-1800 ft MSL.

Mountains/Deserts...Mostly clear with VFR conditions through Sunday
evening.

&&

.MARINE...
No hazardous marine conditions are expected 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...SS
AVIATION/MARINE...KW