Have you ever looked at the radar before heading outside and it shows rain, but then realize nothing is falling? That’s called Virga. It’s rain that evaporates before reaching the ground.

However, sometimes virga can hit the next level, creating something dramatic and rare: a virga bomb!

A virga bomb happens when rain from a dying thunderstorm falls into an especially dry layer of air below the cloud. As that rain evaporates, it rapidly cools the surrounding air, making it much denser. That dense air suddenly plunges downward FAST — which is known as a microburst. When it slams into the ground, it spreads out in all directions with powerful, gusty winds that can create winds as strong as a small tornado.

Weather in your inbox

Forecast Location

Sign Up

By signing up you agree to the Terms & Privacy Policy. Unsubscribe at any time.

On July 1, 2025, a virga bomb occurred around Las Vegas, producing winds as high as 70mph. It triggered a massive dust storm that brought visibility down to almost zero in a matter of minutes, snapped power lines and caused tens of thousands to lose power.

A virga bomb can be dangerous for those on the ground as well as aircraft. It’s one of the atmospheric tricks that can catch pilots off guard, packing surprising power in what seems like a quiet sky.

Jennifer Gray is a weather and climate writer for weather.com. She has been covering some of the world's biggest weather and climate stories for the last two decades.