Sunday, September 29, 2024 9:58 PM

More moisture, flood concerns for parts of the Southeast

Christopher Nunley

All eyes are on the potential for a new developing tropical system in the Gulf of Mexico this week and any potential impacts to the U.S.

Numerical guidance continues suggesting the potential of a tropical system developing in the Caribbean or Gulf of Mexico this week. While guidance is struggling with the exact setup, the National Hurricane Center has moderate confidence in a system developing, thus, there's a 50% chance for development in this region this week.

NHC tropical forecast NHC Gulf of Mexico and Caribbean forecast over the next 7 days

While there's increasing confidence in development, there's a lack of confidence in where the system develops, where it moves and the intensity, and hence, any impacts—if any—to the U.S., especially for areas recovering from devastating rains from Helene.

Regardless of tropical development, it does appear tropical moisture could be funneled into parts of the Southeast late this week into the weekend, possibly sticking around into early next week. Guidance suggests a ridge will set up shop over southern Florida and the western Atlantic and the flow around the ridge could help direct moisture into this region. With that steering pattern around the ridge, eyes will be kept close on any tropical system that develops for a similar trajectory as the tropical moisture. Let's be clear, a tropical system impacting the Southeast is not currently in the forecast but keep checking back for updates over the coming days.

Because of this developing ridge placement and the pool of moisture that's building over the Gulf, the Weather Prediction Center has highlighted parts of the Southeast in a flood risk hazard from western parts of the Florida Coast into the Southeast, including the Carolinas. The hazard outlook highlights where flooding is possible and likely.

WPC 3-7 day hazard outlook WPC 3-7 day hazard outlook

WPC 3-7 day hazard outlook Southeast WPC 3-7 day hazard outlook Southeast

With that said, there are some questions as to how much moisture resides over the region, any potential mechanisms to enhance precipitation and the northward extend of the moisture fetch. The latest 7-day precipitation forecast keeps the focal and heaviest of rain south of I-10 across the South and Southeast, which is great news for areas farther north into Georgia, the Carolinas and Tennessee that do not need any additional rain. With that said, this is fluid and subject to change, especially if a tropical system does develop.

WPC 7-day precipitation forecast WPC 7-day precipitation forecast

This is a waiting game, but it needs to at least be put "on the radar" that there's some concern for more moisture to move into parts of the Southeast late this week into the weekend and there's the potential for a tropical system. Keep checking back for updates.