(CBS/AP) NEW ORLEANS -- With its massive size and ponderous movement, Tropical Storm Isaac was gaining strength as it headed toward the Gulf Coast.
Forecasters say Tuesday will likely reveal whether Isaac will become a destructive hurricane with the usual punishing rains and winds — or something even more destructive, harkening back to the devastation wrought seven years ago by Hurricane Katrina.
Predictions call for Isaac to intensify into a hurricane at any time, then continue to strengthen, possibly into a Category 2 hurricane with winds of about 100 mph by early Wednesday, around the time it's expected to make landfall.
The huge storm's winds could be felt more than 200 miles from its center.
The latest storm track forecast aims at New Orleans. But hurricane warnings extend across 280 miles, from Morgan City, La., to the Florida-Alabama state line.
Isaac could become the first hurricane to hit the Gulf Coast since 2008.
At 2 a.m. EDT, Isaac remained a tropical storm with winds of 70 mph, centered about 145 miles southeast of the mouth of the Mississippi River and moving northwest at 12 mph.
The storm's center was forecast to approach the coast of southeastern Louisiana and Mississippi on Tuesday afternoon or Tuesday night, the Hurricane Center said.
Officials say that, beside the potentially destructive winds and storm surge, they are worried about extreme rainfall.
The Gulf Coast region has been saturated already because of a wet summer. Intense rain could make it easy for trees and power lines to fall over in the wet ground. Too much water also could flood crops, and wind could topple plants such as corn and cotton.