Watch Alex Lehnert's forecast

Sand and dust storms affect about 330 million people in over 150 countries and are taking an increasing toll on health, economies and the environment.

A line of heavy thunderstorms swept across the D.C. region Wednesday evening, unleashing torrential rains that flooded streets and violent wind gusts that toppled trees. The storms produced spectacular skies — including menacing clouds on approach and vivid rainbows upon exiting.

A tornado siren blared in Iowa this afternoon as a funnel cloud could be seen in the backdrop of the famed speedway outside Des Moines. NBC News’ Maggie Vespa reports on the severe weather threats facing millions in the Midwest tonight.

Federal agencies that monitor and forecast storms got heaps of attention on Capitol Hill Wednesday, as Florida prepares to enter peak hurricane season next month.

A hazardous weather alert is in effect for Northeast Ohio, including the Cleveland and Akron areas, as strong to severe thunderstorms and heat move through the region. The National Weather Service warns of damaging winds,

Severe thunderstorms will head east by Saturday, impacting eastern Michigan and parts of northern Indiana. Rain from 1 to 2 inches is possible as the system tracks east, but some areas could see isolated amounts of 3 to 5 inches through the weekend.

Michigan residents should prepare for a potentially stormy Saturday with a high risk of severe thunderstorms and heavy rainfall across multiple regions of the state.

Thousands of people were in the path of a dangerous storm that moved through North Carolina on Wednesday afternoon.