A strong wind and duststorm or sandstorm occurring in northern and central Sudan (World Meteorological Organisation).
The average duration of a haboob is three hours and the average maximum wind velocity is over 15 m/sec (29 kts). The dust or sand forms a dense whirling wall which may be up to 1000 metres high. It is often preceded by isolated dust whirls. Haboobs usually occur after a few days of rising temperature and falling pressure.
The Haboob can also be considered a gust front generated by afternoon convective activity in the Sudan regions described above predominantly from May to September. Unstable (relatively hot and saturated) air is drawn toward the Inter Tropical Convergence Zone (ITCZ) located north of the region. The air picks up sand and dust as it moves towards the ITCZ, reducing visibility and creating the dramatic scenes as per photo below. Afternoon and evening shower and thundershower activity may follow the dust storm, washing out the sand and dust from the air.
The word Haboob is an Arabic word meaning "strong wind".
A massive dust storm cloud (haboob) close to enveloping a military camp as it rolls over Al Asad, Iraq, just before nightfall on April 27, 2005. DoD photo by Corporal Alicia M. Garcia, U.S. Marine Corps. (Released)