725
FXUS66 KSGX 171125
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
425 AM PDT Wed Jul 17 2024

.SYNOPSIS...
Gradual increase in temperatures each day for most areas through
Saturday. Above average temperatures are expected for all areas by
the weekend, with moderate to major heat risk for the valleys and
major to extreme heat risk for the deserts. Major to extreme heat
risk could continue for the deserts into early next week. There are
slight chance of showers and thunderstorms each afternoon in the
mountains into early next week. Coastal low clouds and fog will
continue to reach into portions of the western valleys each night
and morning.

&&

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

.SHORT TERM (Today through Friday)...
Lower level moisture in the lower deserts will increase slightly
for today and again on Thursday with Friday a little drier. A
slight chance for afternoon showers and thunderstorms will return
for this afternoon for the mountains with a little greater
coverage possible on Thursday for the mountains into the deserts
during the afternoon and early evening with Friday drier than
either today or Thursday.

The lower deserts will not be quite as hot for today and Thursday,
then warmer on Friday with the drying. Slow warming is expected
for the coast and valleys for today and Thursday with a little
greater warming on Friday with high temperatures exceeding 100 for
the warmest inland valleys.

Night and morning coastal low clouds will continue to spread into
portions of the western valleys at times late each night.

&&

.LONG TERM (Saturday through Tuesday)...
Strengthening high pressure over the southwest states and Great
Basin will bring warming into the weekend with the heat peaking
over the weekend, but with only slight cooling for Monday and
Tuesday. For the coast and valleys, Saturday is the warmest day
with high temperatures near the coast a few degrees above average
and 5 to locally 10 degrees above average for the valleys and
inland coastal areas.

An Excessive Heat Watch has been issued for the lower deserts for
Friday through Sunday and for the Apple and Lucerne Valleys for
Saturday and Sunday. A Heat Advisory might also be needed for the
valleys and for the lower elevations of the mountains for the
weekend.

A slight chance of afternoon and early evening showers and
thunderstorms will continue for the mountains and deserts with the
chances slightly less for Saturday and Sunday and slightly greater
for Monday and Tuesday. Night and morning coastal low clouds will
continue to spread into portions of the western valleys at times
late each night.

&&

.AVIATION...
170840Z...Coast/Valleys...Stratus with bases 1400-1600 ft MSL and
tops to 1900 ft MSL will continue to spread north into Orange County
and 20-25 mi inland through 14Z, reaching KSNA between 11-12Z. Local
vis 3-5 sm where stratus nears terrain in the valleys. Stratus
clearing inland 14-16Z and near the coast 16-18Z. Low clouds
redeveloping along the coast after 18/02Z, moving into the San Diego
County coastal areas 04-06Z and Orange County coastal areas 06-09Z,
then spreading 15-20 mi inland overnight. Bases will be near 100-
1400 ft MSL with tops to 1800 ft MSL.

Mountains/Deserts...Isolated SHRA/TSRA developing over the mountains
around 20Z, dissipating by 18/02Z. CB bases near 12,000 ft MSL with
tops to 30,000 ft MSL. Gusty outflow winds and reduced vis in RA
VCTY TSRA.

&&

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

&&

.BEACHES...
Long period 3ft SSW swell (200-210 degrees) will bring elevated surf
of 4-6 feet with sets up to 7 feet for south-southwest facing
beaches in both Orange and San Diego counties and a high risk of rip
currents at all beaches. A Beach Hazard Statement remains in effect
through Thursday evening. Swell and surf will begin to lower on
Friday, but the rip current risk will remain high.

&&

.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 Thursday evening for Orange
     County Coastal Areas-San Diego County Coastal Areas.

     Excessive Heat Watch from Saturday morning through Sunday
     evening for Apple and Lucerne Valleys.

     Excessive Heat Watch from Friday morning through Sunday evening
     for Coachella Valley-San Diego County Deserts-San Gorgonio
     Pass Near Banning.

PZ...None.

&&

$$

PUBLIC...17
AVIATION/MARINE/BEACHES...SS