The term “haboob” originated in Sudan, where strong winds, sandstorms or dust storms erupt. Khartoum averages 24 haboobs per year. Other characteristics include an average duration of three hours, with wind velocities over 30 mph. They form when super-cool air ejects from a developing dust storm, creating a massive whirling wall that can elevate to 3,000 feet. Wednesday’s haboob in Phoenix included a 100-mile wide, mile-high dust cloud, pushed by 60-mph winds. A dust storm in 1995 along the Arizona-New Mexico border caused eight highway fatalities and 20 injuries. Las Vegas ranks in the top five regions in the national for airborne particulates because it is surrounded by deserts that kick up dust causing the storms. Dust storms in Australia are called brickfielders.

Fastcast: Fewer showers.

Scattered showers, mainly after 1 p.m. Mostly sunny, with a high near 94. Rain chance: 30 percent. Tonight: Isolated showers before 1 a.m. Partly cloudy, low around 75. Rain chance: 20 percent.