High pressure aloft brought in dry and hot conditions to the deserts from June 3rd through 5th. Extreme heat was observed in the Coachella Valley and San Diego County Deserts, and one person died from a heat-related illness.
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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.
High pressure aloft brought in dry and hot conditions to the deserts from June 3rd through 5th. Extreme heat was observed in the Coachella Valley and San Diego County Deserts, and one person died from a heat-related illness.
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 Jun 2, 8:15 PM PST, 3 hours 45 minutes earlier.
Area Forecast Discussion
National Weather Service San Diego CA
915 PM PDT Sat Jun 2 2018
.SYNOPSIS...
High pressure aloft will bring warm weather through Sunday,
followed by cooling into midweek as a weak upper level low
pressure trough redevelops off the California coast. A shallow
marine layer will keep some clouds and fog along the immediate
coastal strip and then expand spreading inland Monday and Tuesday
allowing a return to seasonable weather the rest of the week.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
Severe clear over Socal land and bight waters today thanks to
large weak closed low (584 dm center) that lifted across the
northern Baja and is now to the east over northern Arizona.
Negative vorticity advection in the wake of the upper low has
effectively mixed out the marine layer and subsidence lowered the
height along with offshore flow in the low levels just above the
surface since Friday. Lower humidity and warmer temperatures
occurred today with desert areas reaching 105 to 110F...under and
just west of the closed upper low. The northeast flow continues
and is evident in the new Aliso wildfire in Orange County with a
smoke plume down the San Diego County coast.
There will be a return to a marine layer clouds late tonight and
early Sunday and should be shallower as warming aloft occurs in
the upper low departure and 500 mb height rises tonight and
Sunday. This sets the stage for some dense fog for the San Diego
immediate coast along I-5 later tonight. There is continued weak
offshore flow above the marine layer tonight through Sunday
morning which will keep it from going inland to I-15 corridor. The
northeast low level flow also not conducive to new eddy
formation.The California bight should have increasing coverage of
low clouds overnight and early Sunday but still broken up within
areas and quick burn off along the land. Dense fog below 800 feet
looks probable during Sunday morning for the immediate coast. The
continued north to northeast flow at 850 mb on Sunday should allow
for clearing out of much of the marine clouds even over the
water.
Will continue the Excessive Heat Warning for the deserts for
Sunday and Monday. 850 mb temperatures rise 2C on Sunday which
sets the air mass for getting closer to 114F for hottest locales.
We start to see changes Sunday night with eddy formation possible
off the LA coast and more favorable but weak northwest low level
flow. There should be widespread low clouds that push inland
further Sunday night and Monday morning...reaching up to 1000
feet. There may be enough for drizzle depending how the upstream
eddy forms. There is only slight cooling on Monday of 1 to 2C of
850 mb temps so the marine layer will deepen with eddy to the
northwest and slightly less inversion. The cooling inland will be
minor but a couple degrees including the deserts on Monday.
Upper heights fall in dirty southwest flow Monday night and an
eddy is forecast to set up over the Bight and closer to San Diego
Coast. Should be a good set up for significant marine cloud push
inland to I-15 and potential for drizzle Tuesday morning.
&&
.AVIATION...
030410Z...Coast/Valleys...SCT010 near the coast through 06Z becoming
BKN-OVC006-009 and spreading 7 miles inland through 15Z Sunday.
Periods of lower VIS of 2-4 miles in FG/BR possible at KSAN and KCRQ
with lower VIS to 1/2 mile at KCRQ possible. Stratus will quickly
clear towards the coast between 15-17Z Sunday with clear skies at
all TAF sites through Sunday evening.
Mountains/Deserts...Clear with unrestricted vis through Sunday.
&&
.MARINE...
Areas of fog with 1 mile visibility forming over the coastal waters
tonight and Sunday night.
.BEACHES...Should see burn off to sunshine on Sunday.
&&
.FIRE WEATHER...Orange County wildfire burned aggressive with
only 15 mph peak winds in canyons and humidity 35-50 percent this
afternoon.
&&
.CLIMATE...Driest year on record for Orange County and fire
behavior evident of this today.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Excessive Heat Warning from 11 AM Sunday to 8 PM PDT Monday for
Coachella Valley-San Diego County Deserts-San Gorgonio Pass
Near Banning.
PZ...NONE.
&&
PUBLIC/FIRE WEATHER...Tardy
AVIATION/MARINE...MoedeThe national radar mosaic for the moment the first event began.
2 heat. Local standard time, as filed.
High pressure aloft brought in dry conditions and extreme temperatures to the Coachella Valley on June 3-5. Temperatures reached 113 in Palm Springs and Thermal on the 3rd and 4th, and decreased to 104 on the 5th.
High pressure aloft brought in dry conditions and extreme temperatures to the San Diego County deserts from June 3-5. Ocotillo Wells reported temperatures of 111 on June 3 and 110 on June 4. One man died on June 4th from a heat-related illness.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Heat, San Diego County Deserts | 2018-06-04 | 34 | Male | Outside/Open Areas | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2018Every state in 2018This day in weather historyWarnings in California, June 2018
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: 767790, 767809.