SPC Issues MD for Haboob

Can it always be caused by thunderstorm winds, or are there acceptions? One thing, that has always baffled me is, how is the dust cloud, able to maintain structure, momentum, and terminal velocity for so long, without a continous wind force being applied on it?
Last night's haboob seemed to owe its staying power to the same basic mechanism that drives derechos. There's a 30-40kt mid-level wind that appeared to be pinned to the surface by the storms' downdrafts.