RALEIGH, N.C. -- North and South Carolina put hundreds of National Guardsmen on standby Wednesday for fear the rainy remnants of Tropical Storm Ernesto could cause severe flooding.

Forecasters said Ernesto could drench the eastern half of North Carolina with as much as seven inches of rain on Thursday and Friday. A separate storm system arriving ahead of Ernesto also threatened to soak the region.

"We could get a clobbering today," National Weather Service forecaster Phil Badgett said.

Ernesto weakened to a tropical depression while crawling north through Florida. Its winds were less a concern to emergency officials than the prospect of downpours.

Ernesto was expected to move off the Florida coast by evening and possibly regain tropical storm strength. Forecasters predicted it would come ashore again Thursday along the South Carolina coast and reach North Carolina by Thursday night.

"We know we're going to get a lot of rain. We know this is going to be a water event," North Carolina Gov. Mike Easley said.

Easley activated 150 National Guardsmen and ordered the State Emergency Response Team to prepare for flooding and power outages. Guard troops in South Carolina were on standby, Lt. Col. Pete Brooks said.

North Carolina has struggled this summer with on-again, off-again drought.

"If we could get the rain where it was spread out over 12 to 24 hours, where it was a good, soaking rain, (flooding) would not be an issue," Badgett said.

On James Island, one of a string of barrier islands on the South Carolina coast, Gerald Galbreath collected 24 sand bags. "It's just precautionary," he said.

At 8 p.m. EDT, Ernesto was centered just northwest of Melbourne, Fla., moving north at near 15 mph. The depression had winds near 35 mph, or about 4 mph below tropical storm strength.