Isaac a Hurricane Now, Less Than 30 Miles from Hunkered Down Gulf Coast

With sustained winds of 80 miles per hour, Isaac is a hurricane now, bearing down on the Gulf Coast shores of Louisiana, Mississippi, Alabama and the Florida Panhandle -- a slow-moving giant carrying violent thunderstorms along its edges and heavy rainful end to end.

Isaac arrives nearly seven years to the day after Katrina. Itbegan pounding the Gulf Coast on Tuesday afternoon with heavy rain and strong winds, gaining strength as the day wore on and prompting warnings about even more dangerous hours ahead.

Having begun Tuesday as a tropical storm, Isaac emerged as a hurricane around noon and has gotten stronger in subsequent hours. By 4 p.m. CT (5 p.m. ET), the storm had maximum sustained winds of 80 mph, with gusts up to 100 mph -- up 5 mph from a few hours earlier -- and was centered 30 miles south-southwest of the mouth of the Mississippi River and 105 miles south-southeast of New Orleans, the National Hurricane Center said.

Steady hurricane-force winds of 74 mph and stronger were felt 60 miles out, mostly to the east and northeast, from Isaac's eye, the Miami-based center added in its advisory.

"Isaac (is) getting better organized," the center's forecasters told CNN News. "Some slight strengthening is possible before it makes landfall."