Haboob

Formation and characteristics

When thunderstorms form, winds move into the storm from all directions, opposite to the storm's travel. As the storm collapses and releases precipitation, wind directions reverse, gusting outward, strongest in the direction of travel. The downdraft of cold, dense air, or downburst, reaches the ground and sweeps up dry, loose silt and clay from the desert, forming a wall of airborne sediment that can be up to 100 km wide and several kilometers high.

During peak intensity, haboob winds reach 35–100 km/h and may approach suddenly with minimal warning. Rain often evaporates before reaching the ground (virga), further chilling the rushing air and propelling it forward. Persistent rain may carry significant dust, leading to mud storms in severe cases.

Occurrence

Haboobs have been observed across the Arabian Peninsula, throughout Kuwait, and in the most arid regions of Iraq, frequently created by the collapse of a thunderstorm. In Africa, they occur in the Sahara and Sahel, most typically in Sudan, resulting from the northward summer shift of the Intertropical Convergence Zone bringing moisture from the Gulf of Guinea. In Australia, haboobs are frequently associated with cold fronts, particularly in the deserts of Central Australia near Alice Springs, where sand and debris can reach several kilometers into the sky and leave up to 30 cm of sand in the storm's path.

In North America, haboobs are often created by thunderstorm collapse and are local or mesoscale events; during extreme drought they can originate in agricultural regions. Some famous dust storms of the Dust Bowl were synoptic scale events generated by strong cold frontal passages, with storms on 11 November 1911, 9–11 May 1934, 14 April 1935, and 19 February 1954 being vivid examples. In the U.S., they frequently occur in the deserts of Arizona, New Mexico, eastern California, west Texas, and the High Plains, as well as the Columbia Basin of Eastern Washington, where improved farming practices have led to a decline since the 1990s, with largest likelihood between late March and April.

In Mexico, they occur in the Sonoran and Chihuahuan Desert; a haboob impacted Guaymas, San Carlos, and Empalme, Sonora on 20 July 2023. Usage of the Arabic term by local U.S. news media has sometimes attracted criticism. Global dust storms on Mars have been compared to haboobs on Earth.

Did You Know?

• The term 'haboob' comes from the Arabic root 'haab' meaning wind or blow.
• The term was first applied to North American dust storms in 1972 by Robert Ingram and co-authors.
• Eye and respiratory system protection is advisable for anyone outside during a haboob.