Increasing Density of Severe Weather Events
September 5, 2011 • 7:54AM

Still reeling from the damage wrought by Hurricane Irene, the U.S. is being hit by tropical storm Lee and may be hit by Hurricane Katia, which is now building up in the Atlantic.

Early Sunday, the center of Tropical Storm Lee stretched across the central Gulf Coast over Louisiana, dumping torrential rains that threatened flooding in low-lying communities in a foreshadowing of what cities further inland could face in coming days.

By Sunday, Sept. 4, at least 6 to 10 inches of rain had fallen in some spots along the Louisiana and Mississippi coasts, and the National Weather Service warned there was a threat of extensive flooding and flash floods because of the storm's movement inland.

The drenching rain bands were expected to head northward into the Tennessee Valley later in the week, as forecasters warned that 10 to 15 inches of rain were possible along the central Gulf Coast and up to 20 inches in isolated spots.

The National Hurricane Center said the flash flood threat could be more severe as the rains moves from the flatter Gulf region north into the Appalachians.

The storm was expected to turn to the east-northeast Sunday night. Maximum sustained winds are near 45 MPH with higher gusts. Tropical-storm-force winds extend outward up to 275 miles from the center. There is also a danger of tornadoes over portions of southern Louisiana, southern Mississippi, southern Alabama, and the far Western Florida panhandle.

At the same time, the National Hurricane Center reports that Katia has become a Category 2 hurricane in the open Atlantic. As of the 11 a.m. Sunday advisory, Katia had maximum sustained winds of 100 miles an hour. It was moving to the northwest at 12 miles an hour. Rapid strengthening is expected, and the National Hurricane Center is advising that Katia could become a major hurricane by Monday. It is still not certain what trajectory the hurricane will follow, and whether or where it will make landfall on the U.S. coast.