Arizona, 2018

Dust Storm in Arizona, April 12, 2018

April 12, 2018 · NWS PSR · 2 events in 2 counties and zones

A large area of low pressure over the desert southwest led to strong and gusty southwest to west winds during the afternoon hours on April 12th. Gusts that exceeded 40 mph at times resulted in areas of dense blowing dust that affected portions of the greater Phoenix metropolitan area; trained spotters as well as Department of Highways personnel reported visibility lowered to one quarter of a…

Where it happened

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.

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  • Floods
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  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

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The toll

Deaths
1
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
2

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 PSR wrote it up.

A large area of low pressure over the desert southwest led to strong and gusty southwest to west winds during the afternoon hours on April 12th. Gusts that exceeded 40 mph at times resulted in areas of dense blowing dust that affected portions of the greater Phoenix metropolitan area; trained spotters as well as Department of Highways personnel reported visibility lowered to one quarter of a mile in a dust storm in the early afternoon hours. No thunderstorms were present at the time, the gusts were generated due to strong low level winds associated with the large low pressure system. Numerous products were issued during the day including Wind Advisories, Blowing Dust Advisories and Dust Storm Warnings.

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 Phoenix, AZ wrote its last area forecast discussion before the first event at Apr 11, 2:02 PM MST, 21 hours 58 minutes earlier.

Area forecast discussion, Apr 11, 2:02 PM MST, 21 hours 58 minutes before
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The radar

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

Open the radar archive at this moment

Event by event

2 dust storm. Local standard time, as filed.

Dust Storm, Northwest Pinal County

When
April 12, 12:00 PM MST to 7:00 PM MST
Where
Northwest Pinal County forecast zone
Reported by
Law Enforcement
Coordinates
32.904, -111.345 (the zone’s center; the record gives no point)

Strong gusty southwest to west winds developed over northwest Pinal County during the afternoon hours associated with a large area of low pressure that had developed over the desert southwest. Wind gusts that exceeded 40 mph at times created areas of dense blowing dust, lowering visibilities to one quarter mile or below and causing dust storm conditions for much of the afternoon. At 1552MST local law enforcement indicated that Interstate 10 near Casa Grande had been closed in both directions from milepost 191 to 194 for over 2 hours due to very poor visibility in dense blowing dust. Additionally, at 1523MST Department of Highways spokesman indicated that Highway 347 was closed for over three and one half hours between Interstate 10 and Casa Blanca Road due to low visibility from blowing dust. Initially a Blowing Dust Advisory was issued for the area, but it was upgraded to a Dust Storm Warning at 1349MST and the warning remained in effect until 1900MST. Fortunately, no serious accidents were reported due to the dense blowing dust.

Dust Storm, East Valley

When
April 12, 1:00 PM MST to 3:00 PM MST
Where
East Valley forecast zone
Deaths
0 direct, 1 indirect
Reported by
Trained Spotter
Coordinates
33.349, -112.491 (the zone’s center; the record gives no point)

Strong gusty west winds developed across the greater Phoenix area during the early afternoon hours on April 12, associated with a large area of low pressure that had developed across the desert southwest. Gusts over 40 mph produced areas of dense blowing dust that lowered visibility down to one quarter of a mile across portions of the east valley. At 1305MST, a trained spotter 2 miles southwest of Chandler reported one quarter mile visibility in a dust storm. Additionally, at 1300MST a Department of Highways employee indicated that visibility had lowered to one quarter of a mile in dense blowing dust. The low visibility was could be seen in an ADOT webcam. No accidents were reported due to the dense blowing dust. A Dust Storm Warning was issued due to the low visibility; it was initially issued at 1334MST and was cancelled at about 1500MST. In related but unfortunate news, a young Mesa father died of Valley Fever that he contracted while caught in the dust storm. He was working outside and got caught in the dust storm; he breathed in the spores and the subsequent fungal lung infection led to his death on June 2. He developed symptoms on May 20 and died 2 weeks later. The family moved to the area in April and he became sick shortly after he was hired. He left behind a wife and a young son.

The people who died

As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.

EventDateAgeSexWhereKind
Dust Storm, East Valley2018-06-0232MaleOutside/Open AreasIndirect

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

More

Every storm in Arizona in 2018Every state in 2018This day in weather historyWarnings in Arizona, April 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: 745619, 745618.