By Michael Peltier
TALLAHASSEE, Florida (Reuters) - Tropical Storm Debby weakened to a tropical depression after it drifted ashore on Florida's Gulf Coast on Tuesday, even as it dumped more rain on flooded areas and send thousands of people fleeing from rising rivers.
After stalling in the Gulf for two days, the large and ragged storm finally began moving eastward. The center crossed the shore late Tuesday afternoon near Steinhatchee, in the Big Bend area where the Panhandle joins the peninsula.
Most of the thunderstorms and rain were northeast of the storm center and had already dumped 2 feet of rain over parts of Florida.
Forecasters at the National Hurricane Center said Debby could bring another 4 to 8 inches of rain - and possibly tornadoes - to north Florida and southeast Georgia in the next two days.
Debby's top winds weakened to 35 miles per hour (55 km per hour) on Tuesday evening, just below the threshold to remain a tropical storm.
It could weaken further, as its center slogged across the northern Florida peninsula, a trek expected to take about 24 hours, but could strengthen again into a tropical storm as it crosses into the Atlantic Ocean, the forecasters said.
Though Debby was still a threat, the hurricane center said a tropical storm warning for the Gulf Coast of Florida had been discontinued. No coastal watches or warnings remained in effect.
Emergency managers in Pasco County on Florida's central Gulf Coast ordered a mandatory evacuation for 14,000 to 20,000 people living between the Anclote and Pithlachascotee Rivers. The Anclote rose from 9 feet before Debby's approach to more than 27 feet, well above major flood level, said Pasco County spokesman Eric Keaton.
Water was ankle-deep to head-high in the evacuation area. Emergency crews had to use boats to reach stranded residents in some areas, and 106 Pasco County homes had been damaged.
"The city has always been prepared for a water event, but I think Mother Nature woke us up as to how fast she can operate," Keaton said.
The storm was piling up coastal waters and pushing them inland, preventing the rainwater from draining out to sea.
Nearly 20 inches of rain has fallen in two days on Wakulla County, a Gulf Coast county famed for its natural springs. Roads were under water in many parts of the surrounding area.
Parts of Interstate 10 were closed between the capital, Tallahassee, and the Atlantic coast city of Jacksonville. The storm left 29,000 people without power across the central and northern parts of the state, emergency managers said.
Tropical storm warnings were in effect for much of Florida's Gulf coast and could be extended inland as the storm moves slowly east over the state in the next few days.
Debby spawned tornadoes that killed a woman, badly injured a child and wrecked homes in central Florida in rural Highlands County on Sunday. Florida's coastal Pinellas County was also hit hard, with flooding in some areas and at least 20 houses with roofs that were partially or fully blown off during a tornado-like storm.
WHITE HOUSE CALL
President Barack Obama called Florida Governor Rick Scott from Air Force One "to ensure the state had no unmet needs" as it responds to the flooding, said White House spokesman Jay Carney.
Obama expressed condolences for the loss of life and damage to homes, and federal authorities "stood ready to provide additional assistance if necessary," Carney said
Scott declared a state of emergency on Monday and ordered all state agencies, including the Florida National Guard, to provide any necessary assistance requested by local governments.
Flash flood warnings were in effect for many areas and emergency managers cautioned that inland flooding was linked to more than half the deaths from tropical cyclones in the United States over the last 30 years.
Debby was the first tropical storm of 2012 to disrupt U.S. energy operations in the Gulf of Mexico. Shutdowns peaked on Monday, when more than 44 percent of daily oil production and a third of daily natural gas production were closed.
Energy companies began returning staff to offshore platforms after the storm veered away from the Gulf oil patch and production was rapidly being restarted.
(Writing by Jane Sutton; Additional reporting by Kevin Gray and Tom Brown in Miami, Laura MacInnis in Washington and Kristen Hays in Houston.; Editing by Tom Brown and Eric Walsh)