Tropical Storm Erin is expected to become a hurricane later today, Aug. 15, and a Category 4 hurricane with maximum sustained winds of 130 mph over the weekend. A major hurricane is a Category 3 or stronger, with maximum sustained winds of at least 111 mph.

Tropical Storm Erin is continuing to pick up strength as it moves across the Atlantic, with forecasters expecting the storm to officially strengthen into a hurricane on Friday, Aug. 15, according to the National Hurricane Center.

Though Erin is not currently forecast to make landfall in the U.S., the East Coast could still get heavy rainfall associated with the storm, along with the northern Leeward Islands, the British Virgin Islands and southern and eastern Puerto Rico. Isolated flash flooding, landslides and mudslides are possible.