Costliest Tropical Storm in U.S. History

The 2001 North Atlantic Hurricane Season wasted no time in getting started as Tropical Storm Allison formed quickly in an area of disturbed weather over the southwestern Gulf of Mexico on just the fifth day of the season.

Allison would make landfall near Houston with top winds near 60 mph, but the main impact from the storm would be heavy rains. The storm circulation would remain intact over land for nearly two weeks, dumping nearly 36 inches of rain in parts of the Houston area and up to 25 inches over parts of Southeast Louisiana.

The 35.94 inches of rain that fell at Greens Bayou, near Houston, is the third highest rainfall total in U.S. history, behind the 45 inches that fell from 1979’s Tropical Storm Claudette and the 40 inches that fell at Thrall, Texas in 1921. The 29.86 inches of rain that fell at Thibodeaux LA ranks as one of the top 5 storm total rainfalls in Louisiana history. Baton Rouge LA picked up 21.36 inches rain for the month, nearing breaking their all time June record.

Catastrophic flooding occurred in the Houston area. More flooding would occur from Georgia to Pennsylvania as the remnants of Allison slowly spun into the Mid Atlantic states.

Twenty two people would die from the floods and some tornadoes in Texas and Louisiana and another 9 in Florida with 4 storm-related deaths in Philadelphia. Allison would become the costliest Tropical Storm in United States history, with preliminary damages near $2.5 billion.

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