Mid-Afternoon Update: Watch Possible
We’ve been fairly calm across the Tennessee Valley for the past few hours, but a few showers are now developing in western areas, specifically in Lauderdale County. More storms are developing along a line of converging winds near I-40. These may continue develop and head southeast during the next few hours.
The storms in Northwest Alabama are forming in the more unstable air, where sunshine has managed break through the clouds.
Currently, the best wind shear support for severe thunderstorms is displaced from the instability into Southern middle Tennessee, but as time goes by, we may see some overlap in the instability and wind-shear providing better support for stronger thunderstorms with a threat for high winds and an outside chance for isolated brief, weak tornadoes.
So far, the situation is not unfolding very quickly, but may accelerate over the next few hours. The Storm Prediction Center is indicating a chance for a tornado watch soon. See Jason Simpson’s post regarding this development.