Forecasters say Tropical Storm Erin, which formed in the eastern Atlantic Ocean on Monday, is expected to become the Atlantic's first hurricane of the season. The storm formed just west of the Cabo Verde islands,

Tropical Storm Erin formed in the Atlantic Monday morning, Aug. 11. Erin could become a hurricane by Aug. 13. Because the flooding has been a growing concern, city officials have installed emergency flood barriers along several miles of riverbanks. Flash flooding has emerged around the St. Louis region after heavy rain Tuesday afternoon.

Erin could potentially strengthen to sustain wind speeds of over 115 miles per hour in the next four days, making it a Category Three hurricane on the Saffir-Simpson scale and the first major hurricane of the Atlantic season.