Thursday’s Ask Storm Team 11 question comes from Geoffrey Smith. He asks: “How does thunder roll that way where it’s more than just a singular clap?”

Let’s first talk about why thunder occurs. When lightning strikes, it heats up the nearby air extremely rapidly. Temperatures can reach of to 50,000F in the lightning channel! This causes the air to expand, but then contract quickly as it cools. This rapid expansion and contraction causes sound waves, thunder!

We don’t hear the thunder instantaneously since light travels fast than sound. And, we don’t hear the thunder the same way every time. The sound of thunder changes with distance from the lightning channel that produce it. 

The loud crack sound indicates the lightning channel is nearby. And you may hear rumbles after the initial crack and the air continues to vibrate from a more distant portion of the strike.

A longer rumble of thunder occurs when the strike is farther away. The shape of the lightning matters too. Shock waves can bounce off each other and create those long, rumbles of thunder.