Adjust font size:
MIAMI, Florida (CNN) -- Hurricane watches have been dropped for most of Florida, as forecasters predicted that Tropical Storm Ernesto would not strengthen before landfall in the Florida Keys on Tuesday night, the National Hurricane Center said.
The storm, which as of 8 p.m. had maximum sustained winds of 45 mph, was expected to hit the Keys by 10 p.m. Tuesday and reach the Florida coast by midnight.
Heavy rain is still expected, and a tornado watch remains in effect for the southeastern part of Florida.
Forecasters predicted rainfall totals of 5 inches to 10 inches near the track of Ernesto. Isolated amounts of 15 inches were possible.
Tropical storm-force winds extended up to 105 miles from the storm's center, and tornadoes could touch down over the Florida Keys as early as Tuesday night, forecasters said.
With the storm projected to skip across southeast Florida and back into the Atlantic Ocean, forecasters Tuesday afternoon extended storm watches northward into the Carolinas.
A hurricane watch was posted from Altamaha Sound, Georgia, to Cape Fear, North Carolina, with tropical storm warnings extending from Altamaha Sound to the tip of Florida and up the state's west coast to Bonita Beach. (Watch how Ernesto could pose a serious problem for Miami -- 1:55)
After crossing Florida, Ernesto is expected to stall in the Carolinas and move into Virginia, and could cause flooding in the Northeast and mid-Atlantic, according to CNN meteorologist Chad Myers.
In Florida, county officials ordered tourists to evacuate the Keys on Sunday, but residents were told to take shelter indoors as Ernesto neared.
A tropical storm warning remained in effect from Englewood, on Florida's west coast, around the Florida Keys and up to Altamaha Sound, Georgia. Tropical storm warnings remained in effect from Englewood to Tarpon Springs.
"While Ernesto is a weak tropical storm, its rains could still cause life-threatening flash floods and mudslides," the hurricane center said.
At 8 p.m. ET, Ernesto was centered about 70 miles south of Miami, the National Hurricane Center reported. The system was moving northwest at 13 mph. (Floridians prepare)
State authorities told residents not to let their guard down because the storm is no longer a hurricane.
"We should not lose people in a tropical storm if people will at least take some safety precautions," said Craig Fugate, the state's emergency management director.
Residents can expect power outages and some flooding, Gov. Jeb Bush said at a news conference, but he warned Floridians not to hoard fuel as the storm nears.
Drivers have been waiting in long lines to fill up their gas tanks at South Florida stations, but Bush said the state has "abundant" fuel supplies.
He also urged Floridians to follow basic safety precautions.
"Don't go outside if you don't have to for a period of time," Bush said. "Don't drive into flooded areas. Don't allow your kids to play in flooded streets, because there could be utility lines down. All the things that common sense would suggest to do, we hope that you will do that."
The Federal Emergency Management Agency has begun to prepare for Ernesto's possible impact on Florida, FEMA Director David Paulison told CNN Monday. FEMA has four urban search-and-rescue teams in Florida, and 13 medical teams in and around the state on stand-by, he said.
The agency has moved supplies into Homestead, outside Miami, and Jacksonville, in northeastern Florida.
NASA decided Tuesday to begin rolling space shuttle Atlantis back into an assembly building as Tropical Storm Ernesto headed for Florida. (Full story)
CNN's Rusty Dornin, Chad Myers and Morgan Neill contributed to this report.