The National Weather Service issued dust storm warnings on Saturday, July 11, for Maricopa, Pinal and Pima counties, putting a dust storm in Phoenix area travel on alert as visibility fell to less than a quarter mile in some places. The warnings covered highway stretches in south central Arizona and southeastern Arizona, including Interstate 10 and Interstate 8.
For drivers, the practical problem was not the dust itself but how quickly it cut the road down to a few feet of usable sight line. Near Eloy, an NWS employee reported visibility dropping to around 20 feet, and the warning language told drivers to avoid dust storms if possible and, if caught in one, pull off the road, turn off lights and keep a foot off the brake.
National Weather Service in Tucson
The National Weather Service in Tucson issued a Dust Storm Warning for Northwestern Pima County until 10 p.m. MST. At 8 p.m. MST, a wall of dust was located along a line from 15 miles northwest of Santa Rosa to 10 miles southwest of Sells and was moving west at 25 mph. The warning covered Route 85 between mile markers 34 and 76 and Route 86 between mile markers 53 and 101.
That warning also described dangerous life-threatening travel in Northwestern Pima County. It left a clear footprint across the northwest side of the county, but the affected roads were limited to the named route segments rather than the whole region.
National Weather Service in Phoenix
The National Weather Service in Phoenix issued a Dust Storm Warning for Maricopa County and Pinal County until 8:30 p.m. MST. At 7:32 p.m. MST, a wall of dust was along a line extending from near Randolph to near Arizola to near Chui-Chu and was moving west at 30 mph. The warning included Interstate 10 between mile markers 186 and 204, Interstate 8 between mile markers 137 and 178, and Route 87 between mile markers 125 and 130.
It also included Casa Grande, Maricopa, Arizona City, La Palma, Toltec, Big Horn, Kaka, Freeman, Arizola, Randolph, Stanfield, Ak- Chin Village and East Chui-Chu. For readers tracking the Phoenix area, that means the county-level warning and the route-level warning did not line up exactly: some locations sat inside the broader county alert, while others were singled out by the later Phoenix-area update.
Southwestern Pinal County
The National Weather Service in Tucson issued a Dust Storm Warning for Southwestern Pinal County until 9 p.m. MST. At 7:33 p.m. MST, an area of blowing dust was located near Eloy and extended west across the southwest portions of Pinal County, with less than a quarter mile visibility and strong winds in excess of 50 mph.
The warning included the northern portions of the Tohono O'odham Nation, Route 87 between mile markers 116 and 124, and Interstate 10 between mile markers 205 and 218. The split end times meant the hazard did not clear at once across the full warned area: one warning ran to 8:30 p.m. MST, another to 9 p.m. MST and another to 10 p.m. MST, depending on where the dust was moving.
For drivers in Maricopa, Pinal and Pima counties, the useful reading was simple: check the exact route segment and county in the warning, not just the county name. A storm line moving west at 25 mph to 30 mph can push the danger zone into a new stretch of road before a single countywide alert looks outdated.
