Surf. Swells generated by Tropical Storm Imelda and Hurricane Humberto are affecting the Bahamas and are currently spreading to much of the U.S. east coast. These swells are likely to cause life-threatening surf and rip current conditions.

Imelda is the ninth named storm of the 2025 Atlantic hurricane season and is expected to strengthen into a hurricane Tuesday.

Article last updated: Monday, Sept. 29, 2025, 11 p.m. ET

Article last updated: Tuesday, Sept. 30, 2025, 5 a.m. ET

That's an unlikely outcome, said CBS News meteorologist Nikki Nolan. But if such a collision does occur, it could produce what's called the Fujiwhara effect, a rare phenomenon in which two different storms merge and become entangled around a newly formed, common center.

Tropical Storm Imelda got stronger on Monday morning and could become the season’s fourth hurricane on Tuesday, according to the hurricane center. Tropical storm warnings remained in effect for parts of the Bahamas on Monday.

A strengthening storm brewing near the Bahamas could bring flooding rain, coastal surge, damaging winds and dangerous surf to the Southeast.

A combination of weather factors and geography helped make it one of the most brutal storms in the modern history of hurricanes.

Article last updated: Tuesday, Sept. 30, 2025, 8 a.m. ET