An upper level high situated over New Mexico and Texas brought hot weather to the inland areas of Southern California. The hottest location was the Coachella Valley, where Thermal reached 117 degrees, and Palm Springs reached 116 degrees on August 21st.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS SGX wrote it up.
An upper level high situated over New Mexico and Texas brought hot weather to the inland areas of Southern California. The hottest location was the Coachella Valley, where Thermal reached 117 degrees, and Palm Springs reached 116 degrees on August 21st. The San Diego Deserts were just as hot, with Ocotillo Wells reaching 117 degrees on August 21st. Up north in the High Desert, many locations were over 100 degrees, such as Apple Valley and Hesperia, where the high was 103 for both locations on August 21st. A few locations in the Inland Empire reached over 100 degrees on August 21st, such as Hemet (104 degrees) and Lake Elsinore (103 degrees). The San Diego Valleys also had hot weather, with many locations reaching 90-95 degrees and Ramona reaching 100 degrees on August 21st. The month of August was dry for all deserts and mountains making it one of the driest on record (under 10 percent of average).
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS San Diego, CA wrote its last area forecast discussion before the first event at Aug 21, 8:20 AM PST, 40 minutes earlier.
Area Forecast Discussion
National Weather Service San Diego CA
920 AM PDT Wed Aug 21 2019
.SYNOPSIS...
Today will be the hottest day of the week with high pressure aloft
over the southwest. Thursday and Friday won't be quite as hot as a
weak trough brings minor cooling and a deeper marine layer.
Temperatures will be about average this weekend through early next
week. There remain small chances for increasing monsoon moisture
this weekend into early next week.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
High pressure aloft will be the dominate weather feature today. It
squashed the marine layer a few hundred feet overnight and the
marine layer clouds didn't even make it into the western valleys of
San Diego County this morning. It will also bring the hottest day of
the week today with highs eclipsing 100 in some parts of the Inland
Empire. It will be exceptionally hot in the lower deserts where
highs of 115-119 are forecast. An Excessive Heat Warning is in
effect through 8 PM in the deserts.
Temperatures trend lower Thursday and Friday as an unusually deep
trough for late August treks inland across the northern Great Basin.
Gradual marine layer deepening will continue through Friday.
Saturday through Tuesday...We will be watching how Tropical
Depression Ten-E evolves. It is forecast to move northwest and
briefly reach hurricane status Friday morning about 900 miles
southwest of the southern tip of Baja, then weaken as it moves
northwest over colder waters. Track uncertainty is usually quite
high with eastern Pacific tropical systems, and this one is no
different. A few of the ensemble members support a little greater
influx of moisture for small chances for precipitation early next
week.
&&
.AVIATION...
211515Z...Coast...Patchy stratus with bases 300-900 ft MSL along the
San Diego County coast and local vis 2-5SM on higher coastal
terrain. Low clouds and vis restrictions expected to clear by 17Z.
Low clouds will redevelop after 07Z Thursday, but remain patchy in
coverage. Local vis of 3-5SM in BR possible in areas of low clouds,
especially on higher coastal terrain.
Valleys/Mountains/Deserts...Mostly clear with unrestricted vis
through Thursday morning.
&&
.MARINE...
No hazardous marine conditions are expected through Sunday.
&&
.SKYWARN...
Skywarn activation will not be needed this week.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Excessive Heat Warning from 11 AM to 8 PM PDT today
for Apple and Lucerne Valleys-Coachella Valley-San
Diego County Deserts-San Gorgonio Pass Near Banning.
PZ...NONE.
&&
PUBLIC...Moede
AVIATION/MARINE...COPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SAN DIEGO CA
739 AM PDT WED AUG 21 2019
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0630 AM DENSE FOG 3 SW ESCONDIDO 33.10N 117.11W
08/20/2019 SAN DIEGO CA TRAINED SPOTTER
DENSE FOG OBSERVED IN ESCONDIDO ON 8/20 AT
6:30 AM WITH VISIBILITY OF 1/8 MILE.
&&
SCThe national radar mosaic for the moment the first event began.
5 excessive heat. Local standard time, as filed.
Many locations throughout the Coachella Valley experienced excessive heat on August 21st. Thermal reached 117 degrees and Palm Springs reached 116 degrees.
Many locations throughout the San Diego desert experienced excessive heat on August 21st. The warmest location was Ocotillo Wells, where the high temperature was 117 degrees.
A few locations in the High Desert reached over 100 degrees on August 21st. Both Hesperia and Apple Valley reached 103 degrees.
Many locations throughout the Inland Empire reached over 100 degrees on August 21st. Hemet was the hottest location at 104 degrees. Lake Elsinore reached 103 degrees.
Many locations in the San Diego County valleys recorded high temperatures of 90-95 degrees on August 21st. The location with the highest temperature was Ramona at 100 degrees.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2019Every state in 2019This day in weather historyWarnings in California, August 2019
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 850017, 850018, 850019, 850020, 850021.