Haboobs were first observed and described in Sudan [Farquharson, 1937, DOI: 10.1002/qj.49706327111]. The word haboob is Arabic and means "blasting" or "drifting". Haboobs generally occur around meteorological phenomena called weather fronts. Mostly, they are related to thunderstorms, which is why very often pictures of these spectacular events are accompanied by dark and rain-bearing clouds. When so-called downdrafts move out in front of the thunderstorm, they can pick up sediments and blow them at speeds up to 100km/h!
Haboobs moving along fronts can be up to 100km wide and up to several km high. Literally several million tons of dust can be mobilised this way and you can imagine that seeing such amounts of material being blown in your direction can be pretty scary!
Not for this couple though; they even managed to shoot a video of driving into a haboob near Broken Hill, Australia: