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Distant dust drives down tropical storm threats

Posted at 6:45 PM, Jun 17, 2020
and last updated 2020-06-25 15:22:29-04

(WTXL) — Tropical storms and hurricanes depends on, among other things, high amounts of moisture in the atmosphere to build and sustain strength. But there are times in the hurricane season when nature zaps away the moisture and keeps activity low.

Airborne dust from the vast deserts on the African continent often contribute to settled periods in the Atlantic Ocean and other nearby waters, limiting the growth of tropical systems.

This dry air source emerges from the Sahara Desert in the warmer times of year and spreads over parts of the Atlantic basin, following natural air flows in the atmosphere. The layer of dry, dusty air is usually about 2 miles thick, and located about one mile above the Earth's surface.

Amounts of dusty air tend to reach their peak from June to mid-August, and can travel the farthest during these months.

The combination of decreased moisture, stronger wind aloft, and warm air acts to decrease tropical storm development in the open Atlantic. The plume of dust can reach the mainland United States, also cutting down formation efforts in the Gulf of Mexico.

On the occasions that it does reach the Big Bend and southern Georgia, the Saharan dust layer can create a hazy appearance to the daytime sky, and add red hues to the setting and rising sun. People with sensitive respiratory systems or related ailments can experience breathing difficulties.