419
FXUS66 KSGX 030946
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
246 AM PDT Wed Jul 3 2024

.SYNOPSIS...
A long-duration heat wave will continue for the deserts through at
least much of next week. Friday and Saturday are expected to be
the hottest days for most areas with the only relief from the
heat toward the coast. The marine layer will slow the warming near
the coast with night and morning coastal low clouds spreading
into the western valleys late each night.

&&

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

.SHORT TERM (Today through Friday)...
Strong high pressure will be centered along the California coast
for Thursday and Friday. High temperatures today will be a few to
around 5 degrees warmer than Tuesday, around 10 degrees above
average for inland areas. Not much change for Thursday, then
several degrees warmer on Friday.

Friday is expected to be the hottest day for many locations, with
high temperatures 10 to 15 degrees above average for inland
areas, with not much change for Saturday. The forecast high
temperature of 123 for Palm Springs on Friday would tie the
existing all-time record high temperature, reached most recently
on June 17th, 2021.

The marine layer will keep coastal areas from warming as much with
night and morning coastal low clouds extending inland to the
western valleys at times late each night.


&&

.LONG TERM (Saturday through Tuesday)...
The center of strong high pressure will move slowly toward the
south for Sunday through Tuesday. Saturday will be nearly as hot
as Friday, then a few to around 5 degrees cooler for the coast and
valleys for Sunday and Monday with slight warming for Tuesday.


&&

.AVIATION...
030900Z...Coast/Valleys...Low clouds are beginning to fill in over
the waters and creep onto the coast early this morning.  BKN-OVC
clouds based 800-1400 ft MSL will move around 15 miles inland later
this morning, before retreating back to the coast 16-18Z Wed. Local
VIS 1-3 miles will occur in the coastal valleys and higher coastal
terrain until 16Z Wed. Low clouds returning with similar bases
after 06Z Thu.

Mountains/Deserts...Mostly clear skies with unrestricted VIS will
continue through this evening. Local south/west winds near 20-30 kts
at times through the San Gorgonio Pass and above the Cajon Pass 22Z
Wed-06Z Thu.

&&

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

&&

.BEACHES...
A swell of 2-3 feet from 190 degrees with a period of 16-18 seconds
will build into SoCal today through the weekend. This will lead to
elevated surf with breaking wave heights up to 7 feet, mainly on
exposed south and southwest-facing beaches in Orange County. Rip and
longshore current risks will be high as well now through next Monday.

&&

.CLIMATE...
This could be an historic heat wave for portions of the lower
deserts in terms of consecutive days of very hot high
temperatures.

For Palm Springs including the observed high temperature of 115
on Tuesday, NBM is forecasting 12+ consecutive days with high
temperatures of 115 or higher. NBM is forecasting 10 consecutive
days with 117 or higher, 8 consecutive days with 119 or higher,
and 6 consecutive days of 120 or higher.

The existing records for Palm Springs are 9 consecutive days of
115+ in 2023, 5 consecutive days of 117+ in 1958, 3 consecutive
days of 119+ in 2021 and 1957, and 3 consecutive days of 120+ in
1957.

The all-time record high temperature for Palm Springs is 123,
occurring most recently on June 17th, 2021. NBM chances for tying
or breaking that record are 16 percent on Friday, 18 percent on
Saturday, 13 percent on Sunday, 24 percent on Monday, and 9
percent on Tuesday. NBM chances for breaking that record are
greatest on Monday at 13 percent followed by 10 percent on
Saturday.

As for daily high temperature records for Palm Springs, NBM has a
85 percent chance on Friday, 88 percent chance on Saturday, and
79 percent chance on Monday of tying or breaking the existing
records for those dates.

As for record warm daily minimum temperatures for Palm Springs,
NBM has a 86 percent chance on Friday and 90 percent chance on
Saturday of tying or breaking the existing records for those dates.

&&

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

&&

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

     Excessive Heat Warning from 11 AM Friday to 9 PM PDT Saturday
     for Riverside County Mountains-San Bernardino County
     Mountains-San Bernardino and Riverside County Valleys-The
     Inland Empire-San Diego County Mountains-San Diego County
     Valleys.

     Heat Advisory from 11 AM Friday to 9 PM PDT Saturday for Orange
     County Inland Areas-Santa Ana Mountains and Foothills.

     Excessive Heat Warning until 9 PM PDT Wednesday for Apple and
     Lucerne Valleys.

     Excessive Heat Warning until 9 PM PDT Tuesday for Coachella
     Valley-San Diego County Deserts-San Gorgonio Pass Near
     Banning.

PZ...None.

&&

$$

PUBLIC/CLIMATE...17
AVIATION/MARINE/BEACHES...APR