Weird weather: Did a tsunami really hit Florida?

A large wave recently crashed onto Clearwater Beach, Florida, on Wednesday 21st June, but was it a tsunami?

The National Weather Service did indeed confirm it was a tsunami on Clearwater Beach, but not your typical kind triggered by seismic activity. It was what's known as a meteotsunami, caused by storms with strong winds.

The wave measured 1.2 feet in height, rare in size for Florida, but not in comparison to dramatic tsunami waves.

Meteotsunamis only last around an hour, and unlike their seismic-driven relative, are caused by fast-moving storm systems and pressure changes over open water.

If the storm is powerful, it can produce violent winds that push onshore, generating a wall of water. In some instances, waves can grow higher as the winds interact with coastal features such as a shallow continental shelf, inlets, or bays.

In the US, meteotsunamis are most common in the Great Lakes, Gulf of Mexico, and Atlantic Coast, though can also occur in other parts of the world. Ciutadella de Menorca, Spain for example, saw one in February 2016 after a low swept by.

If meteotsunamis become large enough, they can inundate coastal areas and sometimes even damage coast-adjacent homes or structures. Although the wave tends to be more local and weaker than earthquake-triggered tsunamis, they are almost undetectable.

Forecasting or detecting meteotsunamis have been a long-time challenge. This is because their characteristics are almost indistinguishable from a seismic tsunami. It can also be confused with other wind-driven waves such as storm surges.