451
FXUS66 KSGX 281022
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
322 AM PDT Fri Jun 28 2024

.SYNOPSIS...
Not much change in high temperatures for today. There will be a
warming trend through weekend with high temperatures on Sunday
around 115 for the lower deserts and around 104 for the warmest
inland valleys. There will be variations in high temperatures of a
few degrees each day during the early and middle part of next
week with high temperatures generally 5 to locally 10 degrees
above average for inland areas. Depending on the placement of
strong high pressure aloft somewhere over the Great Basin and
southwest states, there could be some additional warming for the
end of next week. The marine layer will moderate the heat toward
the coast with night and morning coastal low clouds spreading into
portions of 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 Sunday)...
Southwest flow aloft will continue with drying of moisture aloft
into Saturday. A weak coastal eddy will continue into this morning
with coastal low clouds spreading into portions of the western valleys
early this morning. The marine layer will become gradually
shallower during the weekend, but with coastal low clouds still
reaching western portions of the San Diego County valleys for late
Saturday night into early Sunday morning.

High temperatures today will be similar to Thursday, around 5
degrees above average for the lower deserts and within a few
degrees of average elsewhere. There will be several degrees of
warming for Saturday and Sunday with inland high temperatures on
Sunday 5 to locally 10 degrees above average, to around 115 for
the lower deserts and to around 104 for the warmest inland
valleys.

&&

.LONG TERM (Monday through Thursday)...
Strong high pressure aloft over the eastern Pacific over the
weekend will move toward the West Coast early next week and be
centered somewhere near the Bay Area around Thursday and Friday
and be centered somewhere around the Great Basin and southwest
states by next weekend. High temperatures will remain above
average for all of next week with some day to day variations of a
few degrees in high temperatures for the early and middle part of
next week.

The deterministic NBM keeps high temperatures for Palm Springs at
115 or higher for Sunday through all of next week and into the
following week with probabilities of a high temperature for Palm
Springs of 115 or higher greatest on Friday and Saturday of next
week at 49 percent for each day. The Excessive Heat Watch
continues for the lower deserts for Sunday and Monday, but
conditions sufficient for an Excessive Heat Warning for the lower
deserts could continue for much of next week and into the
following week.

&&

.AVIATION...
280905Z...Coast/Valleys...Low clouds increasing in coverage at this
hour with bases around 1400 ft MSL and tops to 1700 ft MSL. Low
clouds likely to extend 15-20 miles inland by 14Z with local VIS
below 3SM in fog in the valleys. 70-85 percent chance for CIG
impacts at coastal TAF sites 10Z-16Z. CIG/VIS impacts unlikely at
KONT and KSBD. Expect clearing to the coast 16Z-18Z. Low clouds
returning to VCNTY coastal TAF sites 03Z-06Z Sat.

Mountains/Deserts...SCT clouds at or abv 10,000 ft MSL this
afternoon. Otherwise mostly clear with unrestricted VIS through this
evening.

Northwest winds gusting to 45 mph in the wind-prone passes and
canyons again this afternoon with moderate up/downdrafts over and
east of the mtns.

&&

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

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Excessive Heat Watch from Sunday morning through Monday evening
     for Coachella Valley-San Diego County Deserts-San Gorgonio
     Pass Near Banning.

PZ...None.

&&

$$

PUBLIC...17
AVIATION/MARINE...PG