Why Tropical Storm Eta Caught Florida's Gulf Coast Off-Guard

WUSF | By Stephanie Colombini

Published November 12, 2020 at 10:08 PM EST

Much of Tropical Storm Eta's damaging effects were pushed east of its center by wind shear in the Gulf of Mexico.

Many residents in the greater Tampa Bay region had a rude awakening Wednesday upon learning Tropical Storm Eta wasn't slowly making its way toward the Panhandle as expected but instead taking a sharp turn in their direction.

Eta became more challenging to track when it moved into the Gulf of Mexico as it weakened into a tropical storm.

Meteorologist Athena Masson with the Florida Public Radio Emergency Network said tropical storms are typically harder to forecast than say, a Category 5 hurricane, because they rely heavily on other forces in the atmosphere to drive them.

"Eta managed to situate itself in a very prime area, and we had two high pressure systems on either side of it and they were battling it out on which one was going to be the dominant force to pull Eta northward," Masson explained.

Those battling forces are what caused Eta to stall in the Gulf, and Masson said she and her colleagues expected the storm to linger southwest of Florida for another couple days or possibly fizzle out due to wind shear tearing up its center.

But that wind shear pushed Eta slightly east, and Masson said that allowed one of the high pressure systems to drag the storm north toward Cedar Key, where it made landfall early Thursday morning before continuing across the state.

Masson said Eta “was not a pretty storm based on satellite, to say the least,” and the wind shear breaking up its formation created rain bands to the east of its center, drenching Gulf Coast communities and causing flooding and storm surge in some areas even while Eta was still offshore.

“So that [wind shear] pushed most of that cloud cover, most of those heavy winds and especially the rainfall, draping it across the Florida peninsula,” Masson said.

The good news: Masson said the high pressure system that carried Eta out of Florida should now bring most of the state some dry air and sunshine.

“We definitely need it, we need to dry out some areas,” she said. “At least from initial reports that I’ve been seeing, 5-9 inches of rain across portions of the Suncoast, and then over a foot of rain down in South Florida as Eta made its first approach into the state. We need that high pressure to build in.”

With its November landfall, Eta became the latest-occurring named storm to hit Florida since Gordon in 1994, and it is also one of the longest-lasting November storms.

Meteorologists say the lesson residents should learn is not to let their guards down in the fall.

“People need to remember that they need to be ready because hurricane season goes through November,” said Keily Delerme with the National Weather Service Tampa Bay office. “It doesn’t matter if it’s a tropical storm or a Category 5, there always needs to be a plan.”

Here's how the National Hurricane Center's forecast track for Tropical Storm Eta shifted from Tuesday morning, Tuesday afternoon and Wednesday morning.