135
FXUS66 KSGX 231953
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
1253 PM PDT Thu Jul 23 2026

.SYNOPSIS...
High pressure aloft will strengthen into the weekend with high
temperatures for inland areas around 10 degrees above average
through Saturday. Nights will be quite warm with low temperatures
for the deserts as much as 10 to 15 degrees above average. Gradual
drying and slight cooling for the early and middle of next week
with high temperatures for the middle of next week still around 5
degrees above average for inland areas. There is some model
guidance that has a brief surge of moisture into the area on
Sunday which would result in more clouds, high temperatures not as
high for some inland areas, and a slight chance of afternoon
thunderstorms for the mountains.

&&

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

High pressure aloft will continue to build over the area through the
weekend, continuing the hot daytime temperatures and elevated
overnight lows. Highs today will be 5 to 10 degrees above the
seasonal average, locally up to 15 degrees warmer in the valleys and
in the coastal mountain slopes. Daily highs will vary little through
Saturday with a slight cooling of inland high temperatures Sunday
and Monday.

Elevated overnight lows will offer little to no reprieve from the
daytime heat. Coastal areas and inland valleys will see overnight
lows predominately in the 70s, low deserts in the upper 80s to low
90s, and the high deserts in the mid 70s to low 80s.

These high afternoon temperatures and elevated lows will bring
widespread moderate HeatRisk to most of the area with major HeatRisk
in the Inland Empire, San Diego mountains and the low and high
deserts through Monday. Major to extreme HeatRisk indicates that
anyone may be negatively impacted by the heat if the proper
precautions are not taken. Make sure to stay hydrated, stay cool,
avoid heavy activity and direct sunlight and check on the elderly,
children and pets.

Coastal low clouds will continue to form in the late evenings into
the early morning hours, pushing inland as far as 20 miles in some
areas through the weekend at times. A slight increase in monsoonal
moisture will create mid-level clouds over the mountains today and
Friday with a 10-12% chance for light rain in the mountains for San
Bernardino and Riverside Counties.

A little uncertainty exists in regards to temperature and moisture
over the area Sunday. Models differ slightly over the placement of
the upper level high pressure. This will affect how much the
afternoon highs will cool Sunday and the chances for rain and storms
over the area (currently forecasting 5-15%).

Otherwise, afternoon highs and overnight lows are expected to cool
slightly by Monday with conditions drying into mid week.
Temperatures will warm again by mid to late next week as high
pressure aloft once again builds over the area.

&&

.AVIATION...
231730Z....Coast/Valleys...Better clearing today, with only very
localized cigs along the immediate coast into the afternoon. Cigs
developing after 07z Fri across San Diego County, with less than 20
percent chance of cigs at KSNA. Cigs will be 1000-1500 ft MSL. Low
clouds expected to clear coastal areas 15-17z Fri.

Mountains/Deserts...CU over the mtns bases AOA 8000 ft MSL 20Z
through sunset. Otherwise, VFR conditions prevail through the TAF
period.

&&

.MARINE...
Northwesterly winds with gusts 20-25 kts in the outer waters near
San Clemente Island to continue this afternoon and evening.
Additionally, a mixed swell will cause steep and choppy seas 6 to 7
feet in the outer waters today. Winds and seas will decrease
tonight.

&&

.BEACHES...
A 3 to 4 feet south swell from 190 degrees with 13 second period
will bring surf of 5 to 7 feet to area beaches through Sunday.
Highest surf will be on south-southwest facing beaches.

Early next week, a longer period (16-18 second) south swell at 2-3
feet from 190-200 degrees is expected arrive. This will prolong
elevated surf into next week and increase rip current risk.

In addition to elevated surf, tides are expected be increase Friday
to near 5.5, increasing to 6.0 to to 6.5 feet MLLW by Sunday. The
combination of surf and tides will result in minor coastal flooding
during high tides.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.


&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Beach Hazards Statement through Sunday evening for Orange County
     Coastal Areas-San Diego County Coastal Areas.

     Heat Advisory until 8 PM PDT Monday for Orange County Coastal
     Areas-Orange County Inland Areas-Riverside County Mountains-
     San Bernardino County Mountains-San Diego County Coastal
     Areas-San Diego County Valleys-Santa Ana Mountains and
     Foothills.

     Extreme Heat Warning until 8 PM PDT Monday for Apple and Lucerne
     Valleys-Coachella Valley-San Bernardino and Riverside
     County Valleys-The Inland Empire-San Diego County Deserts-
     San Diego County Mountains-San Gorgonio Pass near Banning.

PZ...Small Craft Advisory until 9 PM PDT this evening for Waters from
     San Mateo Point to the Mexican Border Extending 10 to 60 nm
     out including San Clemente Island.


&&

$$

PUBLIC...Villafane
AVIATION/MARINE/BEACHES...CO

NWS San Diego (SGX) Office