727
FXUS66 KSGX 060350
AFDSGX

Area Forecast Discussion
National Weather Service San Diego CA
850 PM PDT Fri Jul 5 2024

.SYNOPSIS...
Hot conditions will continue into at least the middle of next
week. The peak of the heat will occur through tomorrow, but above
average temperatures will continue for all areas into late next
week. The marine layer will continue to moderate the daytime
warming toward the coast with night and morning coastal low clouds
extending into portions of the western valleys at times. Know the
signs of heat related illness and if possible, limit your time
outdoors during the hottest part of the day. Stay hydrated and if
you are spending time outdoors seek shade when possible.

&&

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

Evening update...
With drier conditions across the low deserts and a warming
airmass, Palm Springs managed to break their all-time record high
(since records began in 1922) with a high temperature of 124
degrees, beating the previous record of 123 degrees set on 4
different occasions. Idyllwild also tied their all-time record
high at 104 degrees. The forecast over the next few days calls for
more highs near or above daily records, but hopefully we`re done
with the all-time records for now. In fact, for the Coachella
Valley, hi-res guidance is still indicating a more robust gulf
surge early Saturday with slower drying in the afternoon. This,
combined with a couple degree drop in 850 temps across the lower
deserts, should keep temperatures from climbing as high as they
did today.

The marine layer is clinging to the coast this evening as a
coastal eddy begins to spin up. This will help spread clouds and
cooling a bit further inland tonight into tomorrow, especially
across inland Orange County and the western valleys in San Diego
County. Perhaps even the Inland Empire will feel some of the
effects, though it will still be plenty hot across the interior
portions. Overall highs will be around 3 to 7 degrees above normal
for the coasts and western valleys on Saturday, and around 7 to 14
degrees above normal for the inland valleys, mountains, and
deserts.

Previous discussion...
Temperatures on Sunday are expected to "cool" an additional few
degrees in the valleys and mountains. Moderate to locally major
HeatRisk is still expected Sunday in the Inland Empire and in the
mountains, with areas of moderate HeatRisk through Monday for most
valley locations. Temperatures for areas west of the mountains
are expected to increase again Tuesday into the latter half of
next week, with more widespread moderate to locally major
HeatRisk.

HeatRisk in the deserts is expected to stay major to extreme
through the weekend and into much of next week. Local high
resolution guidance continues to show shallow moisture surges
making it into at least the southern portions of the Coachella
Valley each morning. How much the moisture retreats for the
afternoon heating of the day will greatly impact how high the
thermometer goes. High resolution guidance is indicating a minor
moisture surge Saturday with a more substantial surge Sunday.
Global ensemble guidance is indicating that the atmosphere will
dry out early next week, and without the moisture present
temperatures could reach near record breaking levels in the lower
deserts.

For the middle to end of next week, the position of the ridge of
high pressure is still uncertain. If the ridge pushes further east,
the southerly flow over Southern California will bring more moisture
and a better chance for monsoon storms. Current forecast follows NBM
with 10-12 percent chance of showers Thursday and Friday afternoon
and evening. If monsoon moisture does in fact make it into the area,
that will keep highs in the desert and mountains tapered down but
will bring the potential for more heating west of the mountains.


&&

.AVIATION...
060330Z...Coast...Low clouds will gradually cover coastal areas
overnight with cloud bases of around 700-1200 feet MSL and tops to
1600 feet. Vis reductions 2-5SM in BR over higher coastal terrain.
Scatter out Saturday expected 15-17Z, but with areas of lingering
clouds along beaches thereafter. Low clouds with similar bases to
gradually move ashore after 04Z Saturday evening.

Otherwise, mostly clear skies with unrestricted vis through Saturday.

&&

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

&&

.BEACHES...
A long-period south swell will continue to create elevated surf. The
surf will peak tonight through Saturday before subsiding on Sunday.
Sets of 6-7 feet can be expected on south and southwest-facing
beaches, especially in Orange County. Check the Beach Hazards
Statement for details.

&&

.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 afternoon for Orange
     County Coastal Areas-San Diego County Coastal Areas.

     Excessive Heat Warning until 9 PM PDT Sunday for Riverside
     County Mountains-San Bernardino County Mountains-San
     Bernardino and Riverside County Valleys-The Inland Empire-
     San Diego County Mountains.

     Excessive Heat Warning until 9 PM PDT Saturday for San Diego
     County Valleys.

     Heat Advisory until 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-Coachella Valley-San Diego County Deserts-
     San Gorgonio Pass Near Banning.

PZ...None.

&&

$$

PUBLIC...SS
AVIATION/MARINE/BEACHES...MM