Hesperia, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

249
FXUS66 KSGX 292046
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
146 PM PDT Thu May 29 2025

.SYNOPSIS...
A deep marine layer is keeping some low clouds west of the
mountains. Low clouds continue to clear from inland towards the
coast this afternoon. Strengthening high pressure aloft over
California will bring much warmer weather for inland areas through
Friday, with high temperatures today 5 to 10 degrees warmer than
Wednesday and another 5 to 10 degrees warmer on Friday. Friday
high temperatures could be as much as 10 to 15 degrees above
average for the Inland Empire. This will be followed by a cooling
trend for Saturday through Tuesday, with Tuesday high temperatures
as much as 10 to 15 degrees below average for the mountains. A
closed upper level low pressure system off the coast of northern
and central Baja will draw some tropical moisture northward into
the area during the weekend with the relatively greater chances
for showers over the mountains and on Sunday. A warming trend will
follow for the latter half of next week.

&&

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

This afternoon...The marine layer low clouds have cleared from all
of the area west of the mtns except the San Diego County coastal
areas and western portions of the valleys. Clearing will continue
for a few more hours. Temperatures are lagging a little behind
expectations but triple digits still seem likely in the lower
deserts.

From previous discussion...
High pressure aloft over California will bring 5 to 10 degrees of
warming for inland areas today while the marine layer continues to
moderate temperatures closer to the coast. A further 5 to 10
degrees of warming is expected on Friday for the inland areas.
Friday will be the warmest day this week with high temperatures
as much as 10 to 15 degrees above average for the Inland Empire. High
temperatures will range from the lower to mid 70s near the coast
to the 90s to around 100 for the Inland Empire with 102 to 108 for
the lower deserts. A cooling trend will begin on Saturday as a
closed upper low to the southwest moves northeast.

For the weekend, a closed upper level low pressure system off the
coast of northern and central Baja will draw some tropical
moisture northward into the area with precipitable water values
peaking on Sunday. There is a chance of showers over the weekend
with the relatively greater chances on Sunday and over the
mountains of San Diego County. On Saturday, there is about a 45
percent of measurable precip (0.01 inch) over the San Diego
County mtns and about a 25 percent elsewhere. On Sunday those
chances rise to about 70 percent and 50 percent respectively.
Chances for precip end on Monday morning as the upper low moves
north of SoCal.

The cooling trend will continue through Tuesday with Tuesday high
temperatures as much as 10 to 15 degrees below average for the
mountains. Highs on Tuesday will range from the lower to mid 60s
near the coast to the lower to mid 70s for the Inland Empire with
the upper 80s to mid 90s for the lower deserts. This will be
followed by a warming trend for Wednesday through the end of next
week. A greater return of night and morning coastal low clouds is
expected for Sunday night into Monday morning with the low clouds
extending well inland and across much of the valleys. The deeper
marine layer will persist through Tuesday, then become gradually
shallower for the latter half of next week.

&&

.AVIATION...
292030Z...Coasts/Valleys...Low clouds continue to scatter out of the
San Diego metro area with KSAN scattering out after 21Z. Confidence
in low cloud coverage for tonight into Friday morning is moderate.
Highest confidence in VCTY KSAN and KSNA becoming BKN after 02-04Z,
but areas of far inland Orange County and Inland Empire may remain
FEW-SCT during this period. Bases will lower near 800-1500 ft MSL
with vis restriction in the valleys across higher terrain.
Scattering slightly earlier than today near 18-19Z near the coast.

Other areas...FEW-SCT clouds AOA 20K ft MSL and VFR conditions into
Friday.

&&

.MARINE...
No hazardous marine conditions are expected today through Sunday.
Slight chance of showers across the area by the weekend.

&&

.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...PG
AVIATION/MARINE...APR