Dust Storm in California, July 9, 2018

Name: Dust Storm in California, July 9, 2018
Start: 2018-07-09T00:00
End: 2018-07-09T10:00
Location: California

July 9, 2018 · NWS SGX · 1 event in 1 county or zone

A line of thunderstorms from Arizona pushed into Southern California early on July 9th. The thunderstorm collapsed and produced a gust front, which brought strong winds into the Coachella Valley.

Where it happened

Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $200,000
Crop damage: None recorded
Events: 1

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.

What happened

The episode as NWS SGX wrote it up.

A line of thunderstorms from Arizona pushed into Southern California early on July 9th. The thunderstorm collapsed and produced a gust front, which brought strong winds into the Coachella Valley. These winds kicked up a significant amount of dust, reducing visibility to as low as 3/4 of a mile. The intense winds knocked over a power pole, and resulted in a house fire.

What forecasters said that day

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 Jul 8, 8:12 PM PST, 3 hours 48 minutes earlier.

Area forecast discussion, Jul 8, 8:12 PM PST, 3 hours 48 minutes before

Area Forecast Discussion
National Weather Service San Diego CA
912 PM PDT Sun Jul 8 2018

.UPDATE...
Record heat stuck around for another day across SW CA, with Vista
and Escondido breaking their high temp records, and Santa Ana
tying theirs. The Heat Advisory was allowed to expire at 9 PM for
inland locations since temperatures will continue a downward trend
through the week. Isolated thunderstorms developed over portions
of the mountains and deserts this afternoon, and quickly
diminished just after 5 PM. A rainfall summary and record event
report are headlined on our webpage with the details. The weather
should be quiet overnight, with no additional storms expected. No
additional updates were needed to the forecast this evening.

&&

.SYNOPSIS...
Temperatures will slowly decrease the next few days. Monsoonal
moisture will bring a chance of showers and thunderstorms each
day, mainly over the mountains and deserts. There will be a better
chance of more significant rainfall across more areas on Tuesday
and Wednesday as moisture increases with passing easterly waves.

&&

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

.PREV DISCUSSION FROM 136 PM THIS AFTERNOON...
On Monday the monsoon flow channels a deeper, thicker layer of
moisture and clouds into the region. If the cloud deck is thick
enough, it would suppress the surface heating and destabilize the
atmosphere to where few if any thunderstorms really get pumping.
It seems like that's the scenario that guidance is showing us
right now. However, if the cloud isn't thick enough, we could get
lots of thunderstorms. On Monday night and Tuesday an easterly
wave brings a bit more instability and even deeper moisture to the
region, which continues into Wednesday. Tuesday looks better for
thunderstorms, not only during the afternoons, and not only in the
mountains, but possible light showers or thunderstorms during
nights and mornings and anywhere in the region. Temperatures will
continue to come down close to average by midweek thanks to weaker
high pressure aloft, the added moisture and increased clouds.
Most guidance is showing the moisture tapering off a bit toward
the week's end, so we'll go back to our regularly scheduled
program of thunderstorm chances only in the mountains only during
afternoons. Next weekend might not have any thunderstorms. At some
point our wounded marine layer might come back to give us some
coastal clouds late in the week. Some guidance also shows high
pressure strengthening again for a warming trend, but other
guidance does not. Temperatures a little above average is the best
forecast for now.

&&

.AVIATION...
090330Z...Coast/Valleys...SCT clouds above 10000 ft MSL and
unrestricted VIS will continue through Monday.

Mountains/Deserts...SCT clouds above 10000 ft MSL and unrestricted
VIS will continue through Monday morning. There is a slight chance
of TSRA Monday afternoon, mainly over the mountains, with cloud
bases 8000-9000 ft MSL and tops to 35000 ft MSL. Any storms that
form could be accompanied by strong up/downdrafts, LLWS and surface
gusts over 35 knots.

&&

.MARINE...
No hazardous marine weather is expected through Friday.

&&

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

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.

PZ...NONE.
&&

UPDATE...JJT
PUBLIC...MM
AVIATION/MARINE...Maxwell

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

1 dust storm. Local standard time, as filed.

Dust Storm, Coachella Valley

When: July 9, 12:00 AM PST to 10:00 AM PST
Where: Coachella Valley forecast zone
Property damage: $200,000
Reported by: Broadcast Media
Coordinates: 33.744, -115.994 (the zone’s center; the record gives no point)

An intense line of thunderstorms across Arizona pushed to the west- northwest into Southern California around 0000 PST on July 9th. By 0100 PST, the thunderstorms began to collapse. The outflow boundary produced a gust front, which brought some gusty winds and kicked up a good bit of dust and dirt. The gust front pushed into the Coachella Valley around 0130-0200 PST and greatly reduced visibility through 15z. Visibility of of a mile was reported in Thermal. The intense winds downs a power pole and line onto a house, which caused it to catch fire. A wind gust of 40 knots was reported in Indio. Haze and dust were present in the Coachella Valley for a few hours in the morning of July 9th.

What these are

Dust Storm: Blowing dust that reduced visibility to a quarter mile or less.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in California in 2018 Every state in 2018 This day in weather history Warnings in California, July 2018

Sources

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: 776159.