887
FXUS66 KSGX 060451
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
951 PM PDT Tue May 5 2026

.SYNOPSIS...
Lingering isolated showers will diminish by early this evening.
Dry conditions will prevail through the rest of the forecast
period. A warming trend is expected tomorrow through early next
week. Areas of moderate HeatRisk expected in the valleys and major
HeatRisk in the low deserts Sunday through Tuesday.

&&

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

.New Aviation and Marine Discussion...

At 12 PM, there were still a few lingering showers in the eastern
San Diego valleys. A rainfall summary is headlined on our
weather.gov/sandiego homepage and details observed rainfall over
the past 24 hours. Shower chances will become more confined to the
eastern valleys and foothills this afternoon before diminishing
by early this evening. Dry conditions will prevail through the
rest of the forecast period.

An upper level ridge of high pressure will begin to build over the
Eastern Pacific Wednesday and Thursday, eventually expanding east
over California for the weekend into early next week. This will
result in a steady warming trend for Wednesday into early next week,
with the hottest conditions Sunday through Tuesday. Current forecast
has moderate to major HeatRisk in the low desert, with minor to
moderate in the valleys and High Desert. Confidence is highest for
temperatures in the low desert where the NBM temperature guidance
matches up with ensemble guidance from the ECMWF and GEFS.
Confidence in how hot it will get is lower for areas west of the
mountains where NBM guidance is running about 5 to 6 degrees warmer
than other ensemble guidance.

Current forecast follows the NBM with temperatures as much as 15 to
20 degrees above average for the inland valleys, high desert, and
lower coastal slopes of the mountains by Monday.

By Tuesday, most of the ensemble guidance indicates the ridge aloft
will weaken, which will bring a few a few degrees of cooling to the
area. Weak onshore flow should be maintained through the forecast
period, which would moderate temperatures along the immediate coast.
Additionally, areas of at least patchy night and morning low
clouds and fog are expected to be present along the coast
potentially into portions of the western valleys.
&&

.AVIATION...
060430Z....Coast/Valleys...SCT-BKN low clouds are hugging the
coastal slopes of the mountains and are slowly spreading into the
inland valleys towards the coast. Cloud bases are lower towards
the coast ranging from 2000-4000ft MSL in SD County and
5000-6000ft in OC. Cloud coverage will slowly increase and lower
with cigs 2500-3000ft MSL through 09Z. Low clouds will bounce
between BKN-SCT overnight, clearing 16-18Z. Low clouds are
expected to return to coastal San Diego by 00-02Z Wednesday.

.Mountains/Deserts...Coastal slopes will be obscured in FG where
clouds intersect terrain between 4000-6000ft MSL, occasionally
obscured at elevations as low as 2500ft MSL. Elevated westerly gusts
20-35 kts along desert slopes and into deserts with isolated gusts
of 45 kts through mountain passes continue, slowly diminishing
through 12Z. This will create moderate to strong up/down drafts and
local LLWS in the lee of mountains. Patchy BLDU reducing vis in the
deserts. Low clouds will clear the coastal slopes 16-18Z.

&&

.MARINE...
No hazardous marine conditions are expected through Saturday.

&&

.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
AVIATION/MARINE...Villafane

NWS San Diego (SGX) Office