TAMPA, Fla. (WFLA) — On late summer nights, you can often see flashes off in the distance on the horizon. These flashes are commonly referred to as “heat lightning”.

Technically, there is no such thing as heat lightning! Those flashes of light are real lightning strikes from a thunderstorm. However, those thunderstorms can be quite far away, tens and sometimes even hundreds of miles away, which is why you don’t hear the thunder.

When the storms are that far away, the curvature of the earth blocks most of the thunderstorm. However, these storms are towering 40,000 to 60,000 feet up in the atmosphere so instead of seeing the actual bolt, you’re seeing the reflected flashes of light in the clouds at the top of the thunderstorm. In some cases, you can still see the bolt when the thunderstorm is close enough.

There is no thunder because the sound dissipates quickly as it spreads outward. The lightning strike did create thunder but it can only be heard by those closer to the storm. Light can travel very far distances, but sound stops about 10 miles out from the source in most circumstances. 

When storms are out over open ocean where the surface is flat, the sound can travel a little farther.