A Deluge for the Sahara

Recent heavy rainfall in the Sahara Desert, particularly in Morocco, Algeria, Tunisia, and Libya, has resulted from an extratropical cyclone that occurred on September 7 and 8, 2024. This cyclone brought unprecedented rainfall to regions that typically receive minimal precipitation, with estimates showing accumulations of over 200 millimeters in some areas. The MODIS satellite captured images of the resulting floodwaters, highlighting the stark contrast between the dry landscape before and after the storm. While much of the rain fell in sparsely populated areas, several villages in Morocco experienced destructive flash floods, leading to damaged infrastructure and disrupted services. Moshe Armon, a senior lecturer at the Hebrew University of Jerusalem, noted that this event is unique due to the cyclone's influence, which pulled moisture from equatorial Africa into the Sahara. The phenomenon has also led to the filling of normally dry lakes, a rare occurrence in the region. Researchers have identified only six similar heavy precipitation events in the last two decades that resulted in lake filling. Overall, this event underscores the increasing frequency of heavy rainfall in the Sahara, particularly during summer months, with only a small percentage linked to extratropical cyclones.

- An extratropical cyclone caused heavy rainfall in the Sahara, particularly affecting Morocco and Algeria.

- Rainfall accumulations exceeded 200 millimeters, significantly impacting areas that usually receive little rain.

- Several villages faced destructive flash floods, damaging infrastructure and services.

- The event led to the filling of normally dry lakes, a rare occurrence in the region.

- Researchers noted an increase in heavy precipitation events in the Sahara, especially during summer.