Tropical Storm Humberto Threatens Southeastern US as Fujiwhara Effect Looms

As of September 26th, 2025, Tropical Storm Humberto, the eighth named storm of the hurricane season, is currently swirling over the waters just north of the Caribbean. While forecasts predict that Humberto is unlikely to make direct landfall, there is a possibility that it could interact with another system developing nearby in the western Atlantic.

This potential interaction could result in a rare meteorological phenomenon known as the Fujiwhara effect. The Fujiwhara effect occurs when two tropical storms get close enough to each other to reach a common point, causing them to either merge or spin around a newly formed, shared center. The outcome depends on the relative strength and size of the storms involved.

According to CBS News meteorologist Nikki Nolan, if Humberto and the other developing system do collide, it is more likely that the smaller and weaker system will be overrun and eliminated by the larger, stronger Humberto. However, in very rare cases, the two storms could "dance around each other" before continuing on their separate paths.

Regardless of whether the Fujiwhara effect takes place, Humberto is expected to strengthen over the next few days and potentially impact coastal areas from Florida to North Carolina. The National Hurricane Center is also monitoring a second storm churning near Humberto over the northeastern Caribbean, which could become a tropical depression and then a tropical storm named Imelda, further increasing the chances of storm surge, wind, and rainfall in the southeastern United States.