Hurricane Idalia: What is the ‘dirty side’ of a tropical system?
While the Big Bend region of Florida prepared for the possibility of the first direct hit by a hurricane in more than a century, residents along the state’s west coast were wary of Hurricane Idalia’s “dirty side.”
So, what exactly is the “dirty side” of a hurricane?
It is considered to be the right side, or the upper-right quadrant in the direction the storm is traveling, the Miami Herald reported. While the winds near the center of a hurricane can be the most destructive, the dirty side also includes powerful winds, heavy rain and the highest risk for tornadoes, according to the newspaper.
According to the National Oceanic and Atmospheric Administration, if a hurricane is heading north — like Idalia — the right side would be east of the system.
That means that the west coast of Florida, which includes the Tampa Bay metropolitan area, may escape the heaviest winds but might be impacted by storm surges sweeping into the waterways. Even inland areas like Orlando and Gainesville could be impacted by Idalia’s dirty side, along with areas of Georgia and South Carolina after the storm makes landfall.
Because hurricanes have a counterclockwise movement, the winds on the dirty side blows onshore, pushing water onto the land, WTSP-TV reported.
“It’s kind of slang-ish, but it just means that the worst of the storm surge and the wind are usually to the east of the center as the center approaches the coast,” Mike Clay, chief meteorologist for Spectrum Bay News 9 in the Tampa Bay area, told the Tampa Bay Times.
For Florida’s Gulf Coast, most storm surges occur south of the eye of the hurricane, the Herald reported. For the east coast of the state, storm surges happen north of the eye.
“Water is going to be pushed counterclockwise onto our coastlines from Sarasota all the way to Pinellas and even in Citrus County,” WFLA-TV meteorologist Eric Stone said. “If you’re on the east side of a storm, typically you get a little bit more in the way of rain.”
When rain bands over water come on shore, the friction of land causes spin-up, Stone said. That can lead to isolated tornadoes.
All quadrants of a hurricane will contain dangerous weather, with storm surge posing the biggest threat to residents, the Herald reported.
“There is the potential for tornadoes and overnight tornadoes with that, so we want to make sure people are aware of that risk and have a way to receive those warnings,” Ali Davis, a meteorologist with the National Weather Service’s Tampa Bay office, told the Times.
A resident posted a sign at a home in Cedar Key, Florida, as Hurricane Idalia threatened the area.
American flags are placed on boarded windows ahead of Hurricane Idalia in Cedar Key.
The U.S. Post Office in Cedar Key, Florida, is boarded up in anticipation of Hurricane Idalia.
The beach is deserted at Cedar Key as Hurricane Idalia moved up Florida’s west coast on Tuesday.
Strong winds hit the Gulfport area in Pinellas County on Tuesday.
Debris flies off a roof ahead of Hurricane Idalia in Fort Myers on Tuesday.
High tide hits Fort Myers Beach ahead of Hurricane Idalia on Tuesday.
Water rises above the docks at Fort Myers Beach as Hurricane Idalia approaches on Tuesday.
High tide roars in at Fort Myers Beach ahead of Hurricane Idalia on Tuesday.
Palm trees sway in the wind at Fort Myers Beach ahead of Hurricane Idalia on Tuesday.
Waves crash on Fort Myers Beach during high tide on Tuesday.
People enjoy the beach in the Tampa Bay area on Tuesday as dark clouds gather.
Residents on Clearwater Beach walk along the shore as Hurricane Idalia moved up the west coast of Florida on Tuesday.
A sign informs travelers that Tampa International Airport is closed on Tuesday as Hurricane Idalia approached the area.
A surfer navigates the waves at St. Petersburg Beach as Hurricane Idalia moved up Florida’s west coast on Tuesday.
Residents brace for strong winds in St Petersburg as Hurricane Idalia churns in the Gulf of Mexico.
Sandbags guard a colorful building in St. Petersburg as Hurricane Idalia approaches the area.
A news reporter walks onto a dock ahead of Hurricane Idalia in Cedar Key.
