The tornado touched down in Kathleen and Polk County east of Tampa where there were reports of an overturned 18-wheeler on Interstate 4 and damage to Kathleen Middle School, which had its roof partially ripped off, according to Bay News 9 in Tampa.
No injuries were immediately reported.
Several homes in Pinellas County were damaged by the tornado as well, according to WFLA_TV.
A Tornado Watch has been issued until noon Saturday for Citrus, Hernando, Hillsborough, Manatee, Pasco, Pinellas, Polk counties, News 9 reported.
Nestor developed in the Gulf of Mexico on Friday and is expected to strengthen as it comes ashore along the northern Gulf Coast Saturday with winds up to 60 mph, The Orlando Sentinel reported.