Extreme heat waves favored haboob-generating conditions during the record-breaking “Godzilla” African dust event

Abstract North African dust is frequently transported across the Atlantic to the Caribbean Basin and the U.S.A. in boreal summers, impacting regional weather, climate, and environment. The June 2020 “Godzilla” dust outbreak was the strongest of such events in the last two decades. While multiple factors have been linked to this record-breaking event, the role of the extreme heat waves that developed before and during the event remains unclear. Here, we investigate how heat waves influenced the development of haboob-generating mesoscale convective systems (MCSs) during the “Godzilla” event using observational analyses and numerical simulations. We show that heat waves not only desiccated soil moisture but also steepened the lower-tropospheric temperature gradient and shifted the Intertropical Discontinuity northward, enhancing atmospheric instability and favoring the development of intense MCSs responsible for convective dust storms (“haboobs”). Idealized surface-cooling experiments show that reduced land-surface heating substantially weakens MCS development and reduces dust-generating winds. The study highlights the important role of heat waves in modulating convective dust-storm dynamics and underscores the growing importance of understanding compound heatwave–dust hazards over North Africa.