Mammatus clouds loom overhead

Mammatus clouds cover western Maryland

Stunning mammatus clouds at sunset near Roswell, New Mexico

Stunning mammatus clouds hover over Nebraska

Ominous clouds loom overhead in severe storm

Ominous funnel cloud looms overhead in tornado-warned storm

Eerie funnel clouds appear overhead in wake of possible tornado

Dark clouds loom as tornado outbreak threatens Texas

Beautiful yet ominous storm clouds loom over chocolate town

Ominous clouds loom over Harrisburg

Storm clouds loom over flatland

Ominous storm clouds loom over Texas coast

Harsh winds and stormy clouds looming over the beach

Dark clouds loom as lightning flashes over city

Ominous clouds loom in the distance

Tornado-warned storm looms ominously overhead

Large tornado looms ominously overhead

Thunderstorms loom overhead

Baseball-sized hail splashes in pond as mothership supercell looms overhead

Massive dust cloud looms over Sioux Falls

Massive shelf cloud looms above Falcon 9 rocket before launch

Drenching storms lead to flooding and tornado threats in Texas

Preparations underway for possible storms at the Preakness Stakes

Severe storms to bring flood danger back to eastern Texas and Louisiana

10 ways to keep safe at the pool this summer

Here's your travel outlook for May 16

Storms drench the Southeast