Water Wheel July/August 2022: Opinion

Abstract

OPINION What did cause the April KZN floods? It was the not-so-little girl who caused the trouble. The April KwaZulu-Natal floods that claimed 448 lives – with 88 people still missing at the time of writing – owes its origins to a complex phenomenon on the other side of the planet. Every now and then, winds cool a vast swathe of surface sea east of South America. The Pacific catches a cold, as it were, and the world’s weather sneezes. It’s known as La Niña (Spanish for “the girl”) and we are at present in her grip, meaning generally heavier rains and more frequent floods. And so it happened around the second weekend of April. A cutoff low pressure system began brewing south-east of Durban. These occur when the atmosphere’s usual west-east passage is disrupted, trapping a pool of low pressure in a huge eddy. Where pressure is lower air is freer to rise and the moisture it carries condenses and falls: It rains.

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