Tropical Storm Erin formed in the Atlantic Monday morning, Aug. 11. Erin could become a hurricane by Aug. 13. Two-day rain totals in and near Milwaukee reached over 12 inches in several locations, as a weekend storm battered the area and led to historic flooding.

For now, most reliable computer models that meteorologists use show Erin curving away from the United States, spinning off the East Coast later in August.

The hatched areas on the National Hurricane Center's tropical outlook map indicate "areas where a tropical cyclone — which could be a tropical depression, tropical storm or hurricane — could develop," said National Hurricane Center Deputy Director Jamie Rhome.