Isaac lumbered Tuesday across the Gulf of Mexico, bearing down on the northern rim of the Gulf of Mexico.
The storm's large size threatened to move an enormous amount of water in the northern Gulf with a storm surge forecast to be the biggest impact along a swath of coastline stretching across Louisiana, Mississippi and Alabama.
A storm surge of several feet was likely for the central Gulf Coast and into the Mississippi River Delta as Isaac appeared poised for landfall as early as Tuesday evening.
Isaac has a tremendous amount of moisture associated with it, and up to 10 inches of rain are expected to fall through the central Gulf Coast in areas most impacted by the storm. Even though the center of Isaac may move over New Orleans, it will affect a much wider area.
Elsewhere, the tail end of a cold front will continue to provide rain and some thunderstorms through the Carolinas and Virginia.
The Northeast will see temperatures rise into the 70s and 80s, while the Southeast will see readings in the 80s and 90s. The Southwest's temperatures will rise into the 90s and 100s, while the Northwest will see temperatures in the 70s and 80s.
Temperatures in the lower 48 states ranged Monday from a morning low of 30 degrees at South Lake Tahoe, Calif., to a high of 106 degrees at Palm Springs, Calif.
Weather Underground: http://www.wunderground.com
National Weather Service: http://iwin.nws.noaa.gov