Tornado Watch Potentially Coming Soon to the Southeastern Parts of the Area

SUMMARY… Severe weather risk — including potential for a couple of
tornadoes — will gradually increase the remainder of this evening
and overnight. A tornado watch will likely be needed.

DISCUSSION… The latest water vapor loop shows a strong short-wave trough approaching the lower Mississippi Valley region at this time, and will reach the central Gulf Coast states and Tennessee Valley overnight. As this occurs, a surface cold front will continue advancing eastward, while a cold air dam persisting across the Carolinas and into Georgia/eastern Alabama gradually erodes with time from southwest to northeast.

As the low-level dam/stable layer is gradually replaced by higher theta-e air as low-level theta-e advection increases in tandem with the advance of the upper system, a more favorable thermodynamic environment — in terms of sustaining deep/moist convection — will slowly evolve. Initially, this increase in low-level theta-e — and thus mixed-layer CAPE — will occur from southern Alabama and the Florida Panhandle into southwestern Georgia. As this occurs, in tandem with a corresponding increase in low-level flow, risk for organized/rotating storms will likewise increase.

At this time, it appears that a combination of storms developing near the front, along with additional warm-sector cells spreading northeastward/onshore from the Gulf, will eventually contribute to the increase in severe risk. Along with the potential for a few instances of marginally severe hail, locally damaging wind gusts will be possible, as will a couple of tornadoes. As such, new Tornado Watch issuance is expected to be required in the next 1 to 2 hours.

Category: Alabama's Weather, ALL POSTS, Severe Weather