ST. LOUIS, Mo. – The hazy conditions over the past couple of days have been the result of dust that was swept off the Sahara Desert more than a week ago. Meteorologist Chris Higgins says that the plume has reached us here in the US.

The phenomenon isn’t unusual for May, June and early July, when thick dust plumes often show up in satellite images as milky, atmospheric swathes.

The Saharan dust usually travels about a mile above the surface of the Atlantic in a 2 to 2.5-mile-thick layer of very dry, dusty air, according to Dr. Jason Dunion, a University of Miami Hurricane researcher.

While much of the dust usually remains well above the ground, some dense plumes may cause ground-level air quality issues and cause irritation, especially for those with pre-existing respiratory problems.

Saharan dust plume, seen by the NOAA-20 satellite on June 17, 2020.

Depending on how dense the plume is, Saharan dust can also create eye-popping sunrises and sunsets, marked by deep red and orange hues. Under dense conditions, the sky may appear milky white during the day with the dust blocking light and causing muted sunsets in the evening.

There is a decent chance for thunderstorms tonight, most likely after midnight. A few of the storms may produce strong winds, hail, and potentially brief, localized flash flooding/street flooding.

The storms should sweep through the are between midnight to 5:00 am.

The weekend still appears to be dry and not quite as hot. But triple-digit temperatures appear ready to make a comeback next week.