Tropical Storm Erin sputtered in the open waters of the eastern Atlantic when it was wrapped in a veil of dry, dusty air from the Sahara, which limited the storm’s ability to strengthen. But it’s still set to become a hurricane by the weekend,

The chances that the storm will make landfall in the U.S. have increased slightly after the path shifted south.

Brief: Tropical Storm Erin is likely to become a hurricane in the next 48 hours, according to the National Hurricane Center on Aug. 12.