When does a storm surge typically peak?

By Livia Albeck-Ripka

One of a hurricane’s most deadly and destructive features, according to the National Hurricane Center, is storm surge: the rise in water generated by strong winds pushing ocean water ashore.

These surges can happen quickly, leaving little or no time to act. According to the National Hurricane Center, 6 inches of fast-moving floodwater can knock over an adult. Two feet can carry away a pickup truck or SUV.

So how can you know when to expect a storm surge, and when is it at its worst?

A storm surge usually builds over many hours as the eye of hurricane approaches the coast and peaks around the time it makes landfall, when the strongest winds around the eye are blowing perpendicular to the shore, said Hal Needham, an extreme weather and disaster scientist with GeoTrek, a science communication platform.

These winds force seawater ashore, he said, creating a raging river through coastal communities. Because winds blow counterclockwise during a hurricane in the Northern Hemisphere, water levels usually rise most on the right side of a hurricane, creating the worst effects for communities in that region.

According to the National Hurricane Center, the areas likely to be worst hit by Hurricane Ian are south of Tampa, from the middle of Longboat Key to Bonita Beach. There, water could rise up to 12 feet above ground level.

“It’s moving in violently,” Needham said, noting that some communities expecting a storm surge had not been faced with one as significant in human memory. “The impacts can be catastrophic.”