Mid-Level Disturbance Sparks Buoyancy Surge (Image Credits: Flickr)
ArkLaMiss region – Forecasters highlighted a Slight risk of severe thunderstorms stretching from the Arkansas-Louisiana-Mississippi confluence eastward into north-central Mississippi and Alabama on Thursday.[1][2]
Mid-Level Disturbance Sparks Buoyancy Surge
A mid-level disturbance tracked southeastward from the central High Plains toward the ArkLaMiss area by late Thursday. This feature combined with a cold front accelerating along the Mississippi-Tennessee border and into the central Gulf Coast states. Modest cold-air advection steepened lapse rates between 700 and 500 millibars across Mississippi and Alabama during the afternoon. Additional daytime heating amplified buoyancy, with surface-based CAPE climbing above 1,500 J/kg in western zones and dipping below 500 J/kg farther east.
Weak low-level winds contrasted with robust mid- and upper-level flow, producing effective shear exceeding 40 knots. Such conditions favored storm organization, including potential supercells as convection fired mid-afternoon. Storm coverage promised to scatter initially before transitioning to more pulse-like modes by evening.[1]
Hail Emerges as Leading Hazard
Large hail stood out as the primary threat, with the Storm Prediction Center delineating a 15% probability contour for severe hailstones. Scattered thunderstorms held potential to produce isolated severe hail, particularly where supercells intensified. Damaging wind gusts earned a smaller 5% probability area, reflecting gusts possibly topping 50 knots in stronger cells…