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What is the ‘dirty side’ of a hurricane?

Key West Fire Department works on a strip mall fire on Flagler Ave., in midtown Key West, Fla., in the aftermath of Hurricane Ian's tropical winds, Wednesday, Sept. 28, 2022. (AP Photo/Mary Martin)

(NewsNation) — Florida is in the throes of Hurricane Ian, which made landfall Wednesday afternoon.

Although hurricanes are dangerous no matter what side of them you’re on, certain weather conditions such as storm surges, even heavier rain, and stronger wind gusts are more likely on the storm’s “dirty side.”


A storm’s “dirty side” can be “the most powerful and destructive section” of a hurricane, according to the Miami Herald.

what is the ‘dirty side’ of a storm?

The National Oceanic and Atmospheric Administration says tropical cyclones tend to be symmetrical, meaning the winds should be the same in all quadrants at a given distance from the center.

Most hurricanes, though, are constantly moving. The direction the storm moves in will add to or subtract from its winds. When the storm’s forward motion is going in the same direction of the vortex of hurricane winds, the Miami Herald wrote, that can create strong and damaging winds — also known as the “dirty side” of the storm. That same forward motion, though, subtracts from hurricane wind speeds on the back end.

“For example, a hurricane with 90mph winds moving at 10mph would have a 100mph wind speed on the forward-moving side and 80 mph on the side with the backward motion,” NOAA said.

Where the dirty side of a hurricane can vary, but the Miami Herald reports that it’s generally the right front section of the storm, in the direction it is headed.

Brian McNoldy, a senior research associate at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science, told the Miami Herald that the dirty side to a hurricane encompasses the entire right portion from the eye. Areas in the “dirty side” of a hurricane that are close to the eye of the storm will likely see the worse winds.

While the other side of storm will still have winds, WTSP wrote these blow offshore, meaning there’s less of a threat of storm surge, and also, it’s less likely to create tornadoes.