In the Gulf, Invest 98L has a low chance for development, before it moves inland over northeastern Mexico or southern Texas by late Friday. The National Weather Service in Brownsville, Texas, said regardless of tropical development, locally heavy rain and increased swells "will be a concern" along the Texas coast.

Tropical Storm Erin is expected to strengthen, but will the storm be a direct hit to Delaware and the East Coast? See models, the latest updates here.

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.