Eta reached hurricane strength for the second time as the Category 1 storm made its approach toward Florida's west coast early Wednesday.
A hurricane watch is in effect for Anna Maria Island to Yankeetown, where hurricane conditions are possible within 24 hours, forecasters said.
By Thursday, "life-threatening storm surge" could occur on portions of the Florida Gulf Coast from Bonita Beach to Steinhatchee River, including Tampa Bay and Charlotte Harbor, forecasters said.
As of 7 a.m., Eta was 130 west-southwest of Fort Myers and 170 miles south-southwest of Tampa, moving at 15 mph, according to the hurricane center.
The latest forecast track has Eta offshore of the southwest coast of Florida on Wednesday, making an approach toward the west-central coast of Florida Wednesday night, and then traveling inland over the northern portion of the Florida Peninsula on Thursday.
A tropical storm warning and a storm surge watch were issued for Florida's west coast from Bonita Beach to the Suwannee and Steinhatchee rivers, including Tampa Bay and Charlotte Harbor. A tropical storm warning is still in place for Dry Tortugas.
A tropical storm watch is in place for Florida's Gulf Coast from north of the Suwannee River to the Aucilla River.
Eta should start to weaken Wednesday night or early Thursday due to storm-shredding wind shear.
Ken Graham, director of the National Hurricane Center, said the storm was entering a "hostile environment" of dry air and wind shear that would limit the extent it could strengthen.
Although the storm has churned away from South Florida, the region remains on high alert for rain and flooding Wednesday.