SPC Mesoscale Discussion: Severe Potential… Watch Unlikely

SUMMARY…Strong storms may pose at least some risk for potentially damaging wind gusts late this afternoon. While it still appears unlikely that this will require a watch, trends will be monitored.

DISCUSSION…Insolation within a very moist boundary layer (characterized by mid/upper 70s surface dew points) has contributed to a pre-cold frontal corridor of large CAPE (up to 3000 J/kg), along an axis across central Mississippi through northwest Alabama and southern Middle Tennessee. This has become the focus for increasing thunderstorm development, aided by forcing associated with a subtle mid-level trough within generally light westerly deep layer mean flow. Embedded within the weak troughing, a remnant mesoscale convective vortex is evident migrating across middle Tennessee, perhaps accompanied by a belt of at least modest (20-30 kt) flow in the 700-500 mb layer. This may be contributing to sufficient shear to support some organization of convection as it attempts to gradually grow upscale through the remainder of the afternoon. If this occurs, there may be a period of increasing potential for strong surface gusts approaching severe limits along expanding, strengthening surface cold pools. Otherwise, a few downbursts appear possible, accompanied by localized potentially damaging wind gusts.

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