Full access rapid mesoscale environmental changes accompanying genesis of an unusual tornado

Storm-relative helicity suddenly increased to large values during this pretornadic period as a midtropospheric layer of strong southeasterly winds descended to low levels. The following events also occurred simultaneously within this short period of time: a pronounced decrease in midtropospheric equivalent potential temperature θe accompanying the descending jet, an increase in low-level θe associated with the surface sensible heating, and elimination of the capping inversion and convective inhibition.

The simultaneous nature of these rapid changes over such a short period of time, not fully captured in Storm Prediction Center mesoanalyses, was likely critical in generating this unusual tornadic event.