High-impact storm to dump several inches of rain across the South and Southeast

A potent low will develop over the northern Gulf of Mexico late Friday night into early Saturday, which will aid in heavy rain from Texas east to the Carolinas through the weekend into early next week. The low will develop in response to an upper-level trough that is digging into Texas. This trough is expected to close off into an upper-level low late Friday. This will help allow the surface low to develop and quickly intensify.

While this low will not acquire tropical characteristics (the surface waters of the Gulf of Mexico are too cool right now), it is still expected to cause big impacts across the South & Southeast through early next week. The primary impact is heavy rain that may lead to isolated areas of flooding but a few other impacts are: severe thunderstorms & tornadoes, gusty winds & high seas that may lead to coastal flooding.

This low will pull in adequate Gulf moisture into the South & Southeast allowing for a large shield of moderate to heavy rain beginning late Saturday and continuing through Monday. A widespread 2-4″ is in the forecast with isolated 5-8″ amounts. Flash flooding is possible, especially for areas near and south of I-20 (Louisiana, Mississippi and Alabama) late Saturday into early Sunday with the flood hazard shifting east into Georgia and South Carolina late Sunday into Monday.

As the storm begins to get its act together late Saturday into Sunday, gusty winds are possible along the Gulf Coast from eastern Louisiana to the western coast of Florida. The elevated wind threat will eventually impact eastern Florida up through the Carolinas late Sunday into Monday as the low moves northeast. The counter-clockwise winds around this low may allow water to “pile” along the northern Gulf Coast that may lead to some salt-water flooding. Isolated severe thunderstorms are also possible along the Gulf Coast this weekend with the best chance on Sunday for the southern half of Florida. The main hazards are damaging winds but isolated tornadoes are possible. 

Let’s time out the onset and ending of precipitation. The graphics below are estimates from our numerical models in Central time.

This system is rather warm so the snow threat appears to be greatly limited in the southern Appalachians. The low will quickly race out to sea by early Tuesday, thus, impacts are not expected across the Northeast.