Humberto becomes a hurricane and may soon be joined by Imelda, posing a US threat

A rare weather pattern is unfolding in the southwestern Atlantic with the possibility of two hurricanes swirling within a few hundred miles of one another. At least one could make landfall along the United States' coast early next week, potentially posing a significant risk from flooding rain, damaging wind gusts and coastal inundation.

"The proximity of two storms expected within hundreds of miles of each other has made this a challenging and complex forecast," AccuWeather Lead Hurricane Expert Alex DaSilva said.

Despite the challenges, AccuWeather hurricane experts are becoming increasingly concerned about the possibility of a landfalling storm along the southeastern U.S. coast next week.

The setup is rare and highly complex. The last time something similar occurred near the U.S. was