In Sahara Desert, Fall Deluge Filled Dry Lakes

An unusual early September cyclone drenched large parts of Morocco, Algeria, Tunisia, and Libya, filling dry lakes and rivers. New satellite imagery from NASA shows the impact of the deluge.

Some parts North Africa saw up to 8 inches of rain, as much as they would typically receive in a year, with waters flowing out of the mountains and into ephemeral lakes, such as Sebkha el Melah in northern Algeria. As of last week, the lake spanned more than 70 square miles and extended to a depth of more than 7 feet — enough water that it could take a year for the lake to dry up.

Of the hundreds of storms to cross the region since 2000, only six, all of them cyclones, unleashed enough rain to begin filling Sebkha el Melah, a recent analysis found. Of those, only two left the lake more full than last month’s deluge.

Where humid air from near the equator collides with hot, dry air further north, the Sahara Desert tends to see more rainfall. This latitude of this collision is moving further north as the planet warms, scientists say, and will likely continue to do so in the next couple decades.

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