By Rich McKay
(Reuters) -Tropical storm Debby formed late Saturday and was expected to surge up into a hurricane before it slams into Florida's northern Gulf Coast shoreline on Monday, the National Hurricane Center said.
The storm turned into a tropical storm after days of spinning as a broad, sloppy system in the Atlantic, finally shoving off Cuba's northern coast on Saturday evening, when it was about 100 miles west-southwest of Key West, Florida, forecasters said.
"It's become clearer and clearer that Debby will become a hurricane before it makes landfall," said Jamie Rhome, the deputy director of the NHC, urging people to heed evacuation orders.
The storm was crawling at 14 mph (23 kph) into the Gulf Coast about 240 miles (386 km) south of Tampa, where its winds were expected to grow from 40 mph up to 70 mph or more as it gains strength overnight.
"This is a life threatening situation," the NHC said in a late Saturday report.
Debby was already whipping up rain squalls, winds of 40 mph and surging tides in Key West, Florida on Saturday night.
"There are a host of hazards, not just the wind," Rhome said.
He warned of storm surges up to 7 feet (2 m) along Florida's Big Bend area where it is expected to hit just southeast of Florida's Panhandle.
"Now, I stand at six feet tall," Rhome said. "So that's over my head," he said.
He added that heavy rains of 10 inches (25 cm) with spots of 15 inches of rain could be expected, more if the storm slows down or stalls over land.
Debby is expected to cut across Central Florida out to the Atlantic coast and crawl up to Savannah, Georgia, and then toward Charleston, South Carolina.
Ocean surges are forecast for Bonita Beach northward to Tampa Bay. Those surges could send sea waves further inland than normal, damaging structures and endangering anyone in their path.
Parts of three Gulf Coast Florida counties, Pasco, Hernando and Citrus, issued mandatory or voluntary evacuation orders on Saturday.
A tropical storm warning is in effect for extreme southern Florida and stretching as far north as the Fort Myers area, which was crushed by Hurricane Ian in 2022.
Governor Ron DeSantis has called up 3,000 National Guardsmen and put most of the state's cities and counties under emergency orders ahead of the expected landfall.
U.S. forecasters expect a large number of Atlantic hurricanes to form in the 2024 season, which began June 1, with four to seven major hurricanes forming out of 25 named storms. That is more than the record-breaking 2005 season that spawned hurricanes Katrina and Rita.
Only one hurricane, Beryl, has formed in the Atlantic so far this year. The earliest Category 5 storm on record, it ravaged the Caribbean and Mexico's Yucatan Peninsula before rolling up the Gulf Coast of Texas as a Category 1 storm, with winds up to 95 mph.
Debby is expected to follow a similar track as the deadly 2022 Hurricane Ian, which killed at least 103 people in Florida and caused billions of dollars in damage as it made its way along the Gulf Coast.