What is a "haboob?"

Haboob (‘blasting/drifting’ in Arabic‎) is a type of intense dust/sand storm carried on a weather front. They were first named in Sudan for the sandstorms most commonly seen in the summer in the Khartoum region.

Haboobs are frequently created by the collapse of a thunderstorm. When this downdraft of cold air, or downburst, reaches the ground, it blows dry, loose silt and clay up from the ground, creating a wall of sediment that precedes the storm cloud. These storms can carry and transport large amounts of dust and sand, with the leading edge being composed of a wall of thick dust as much as 15,000 ft. (4.5 km) high and 60 to 90 mi (96 to 145 km) wide. Haboob winds can travel at 22-62 mph (35–100 km/h), and they may approach with little or no warning. Often rain does not appear at ground level, evaporating in the hot, dry air (a phenomenon called virga). The evaporation cools the rushing air, accelerating it. When the rain does persist, it can contain a considerable quantity of dust. Severe cases are called mud storms. Dust storms have been linked to outbreaks of Valley Fever in the U.S. Southwest, possibly caused by fungal spores in dust.

Haboobs occur regularly in any arid region of the world. Global dust storms on Mars have been compared to haboobs on Earth.

In North America, they are most commonly called dust storms or sandstorms. They often occurred during the Dust Bowl years of the 1930s, with one “black blizzard” famously reaching New York City in 1934.