Tropical systems' interaction could shield Carolinas

As a wet tropical system chugged north toward the Bahamas on Saturday, its threat to the Carolina coast might be determined by its unusual interaction - maybe even a rare dance - with another tropical system that could steer the mess out to sea.

- BY SETH BORENSTEIN AND MICHAEL PHILLIS

A still unnamed and developing tropical depression - likely to become Imelda - is heading toward the Carolinas and is expected to become a hurricane with the potential to bring damaging heavy rains, especially if it stalls and keeps dumping rain for a while.

The storm could hit early this week, so residents of North and South Carolina need to be aware, especially of rain and flooding possibilities. But slight changes in its path and speed will determine how Hurricane Humberto, a big, bad storm already, might come to the rescue.

Humberto, which is farther east and threatening the U.S. territory of Puerto Rico, may get close enough to the future Imelda and start to interact. One possibility is that Humberto, which reached major hurricane status late Friday afternoon, could tug the smaller storm to the east. But if Humberto stays far enough away, it could allow Imelda to hover off the coast or make landfall.

"Even if we expect a slowdown and an eastward turn, exactly when that starts and where it happens will make a big difference in how close the center gets to the coastline," said National Hurricane Center Director Michael Brennan.

As Imelda heads past the coast of Florida, Brennan said, there's a tropical storm watch for parts of the state's east coast. That means winds of at least 39 mph.

"There's going to be a high risk of rip currents. People are not going to want to be out in the water," Brennan said.

As the storm proceeds north, the Carolinas could face a significant flooding threat.