While summer dust plumes are a common occurrence, this appears to be one of the most extreme in recent memory. It's so large it has been nicknamed the Gorilla Dust Cloud. 

"This is the most significant event in the past 50 years. Conditions are dangerous in many Caribbean islands," Pablo Méndez Lázaro, from the University of Puerto Rico's School of Public Health, told the Associated Press.

On satellite images from space, dust typically appears somewhat subtle and faint, but this plume can be seen as clear as day. The picture below was taken on Sunday from the International Space Station. "We flew over this Saharan dust plume today in the west central Atlantic. Amazing how large an area it covers!" astronaut Doug Hurley tweeted.