A dust plume that originated in the Plains states has settled in over the Tennessee Valley.
The plume, which has thickened over the day, originated in Nebraska, Kansas and Oklahoma after strong windstorms stirred up the dust and carried it east, according to the Chattanooga-Hamilton County Air Pollution Control Bureau.
"We have seen like this before, but it usually comes from wildfires or dust fires," said bureau spokeswoman Amber Boles.
Boles said the plume will dissipate when winds pick up, but it is unclear how soon that will be.
At this point, Noles says air quality levels are safe, though the APCB is continuing to monitor them.
"If those levels become unhealthy, we will notify the public," Noles said.