A larger-than-normal cloud of dust, kicked up by winds over the Sahara Desert, is moving across the Atlantic Ocean and will reach parts of the U.S. — including Texas and other Gulf Coast states — by the end of this week, Severe Weather Europe reported.
Officially known as a Saharan Air Layer, events like this happen pretty regularly. Routine late spring-early summer weather patterns over the Mediterranean Sea and North Africa kick up Saharan dust into the atmosphere. Then, carried by the same tropical winds that move hurricanes and tropical storms into this part of the Western Hemisphere, the dust cloud is moved across the Atlantic and toward the U.S. and Caribbean.
The one that’s currently making its way across the Atlantic is larger than usual. Further, the concentration of dust within is denser than usual, tweeted University of Maryland scientist Santiago Gassó.
“This dust event over the N. Atlantic is unusual not only in the extent but also in large area w/high dust concentration,” he wrote.
And it’s expected to reach the southernmost portions of the mainland U.S. — to include parts of Florida, Texas, and Louisiana — by the end of this week.
A large plume of dust has moved off the west coast of Africa during the last few days. As this dry and dusty Saharan air layer moves across the tropical Atlantic toward the Caribbean it will help suppress the development of tropical systems. pic.twitter.com/fCoTw2xvl0
— NWS Eastern Region (@NWSEastern) June 18, 2020
Already the westernmost edges of the dust cloud have reached portions of the Caribbean, darkening skies and cutting down on local air quality, according to The Weather Channel.
In Puerto Rico, for example, a wispy haze hung in the atmosphere.
Saharan dust is coming to #PRWX and #USVIWX. There may be a few showers tonight but then the loaded air will arrive. It will be most dense on Monday. pic.twitter.com/UpMEFU0sP4
— NWS San Juan (@NWSSanJuan) June 20, 2020
And in the Lesser Antilles, local authorities have deemed the air quality “unhealthy.”
These naturally occurring weather events bring both good and bad outcomes.
For example, the microparticles of dust can help fertilize the soil, particularly if they reach the Amazon basin, replenishing the region with nutrients. Similarly, according to NASA, these storms are beneficial in maintaining Caribbean beaches.
Conversely, the sudden influx of nutrients can cause toxic algae blooms in some bodies of water, depriving plants and animals of much-needed oxygen. Such an event is known colloquially as a “red tide,” as the high concentration of algae gives the water a reddish hue.
However, the biggest benefit to these dust storms is that they can suppress hurricanes. Indeed, the layer of dust creates strong down draft around tropical storms, which in turn can prevent them into organizing into stronger storms such as hurricanes. However, it bears noting that these storms’ overall effect on hurricane season is not fully understood.
Additionally, residents in populated areas affected by these dust storms can expect to see “spectacular” sunsets and sunrises, as the sun’s rays filter through the clouds of dust.