The image above is from Bardabos (via @ArcaneWx). It shows massive dust concentrations, in an otherwise clear sky, with only a few low-altitude clouds. The Sun (lower left) is almost blocked out by the dense dust layer.

An unusually large Saharan dust cloud is moving across the Atlantic. It will reach Caribbean and the southern United States by the end of the week

A massive plume of dust from the Sahara Desert is the thickest in years to reach parts of the Caribbean, and some of the dust is expected to move into the Gulf of Mexico and parts of the United States later this week.

At a Glance:

An expansive plume of dust from the Sahara Desert has surged into the Caribbean Sea.
The dust is the thickest to move over the Puerto Rico area in years.
It is forecast to complete a 5,000-mile journey to the U.S. Gulf Coast later this week.
This Saharan air layer generally hampers tropical cyclone development.
The dust-laden air also produces spectacular sunrises and sunsets.

Known as the Saharan Air Layer (SAL), this dry dust plume commonly forms from late spring through early fall and moves into the tropical Atlantic Ocean every three to five days, according to NOAA’s Hurricane Research Division (HRD).

The densest plume began to emerge off western Africa last weekend and has now traveled 3,000 to 4,000 miles across the Atlantic Ocean and the Caribbean Sea, heading toward the southern United States and U.S. Gulf Coast by this weekend.

Saharan dust tracks as far west as the Caribbean Sea, Florida and the Gulf of Mexico each year – a 5,000-mile-long journey.

You can see this in the forecast below from NASA’s GEOS-5 model. Photos by NASA and Weather Channel

Dust plumes like these typically become less concentrated the farther to the west they move.

This particular dust event is unique because of its thickness over parts of the Caribbean Sea. It had the highest concentrations of dust particles observed over Puerto Rico in at least the last 15 years, according to Dr. Olga Mayol of the Institute for Tropical Ecosystem Studies at the University of Puerto Rico.

A thin layer of dust even coated cars and other exterior surfaces in Puerto Rico, as shown in the tweet below.

A thin layer of #Saharandust is in the surface of our cars, exterior tables, fans, etc. This extraordinary dense SAL was lifted from the Saharan desert and traveled to the Caribbean. The red color comes from the iron minerals that travel in this layer. pic.twitter.com/DRLP13kXRp

— Ada Monzón (@adamonzon) June 23, 2020

The core of the dust plume is currently forecast to reach the southern United States by the weekend. Highest concentrations are currently forecast over east Texas and Louisiana, with all of the southeastern states being affected, especially in the coastal areas. Photo by Severe Weather Europe