re: Severe Weather for Friday

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...Southeastern Great Plains into central Gulf States...
While there appears reasonable model consensus on the general
large-scale pattern evolution, considerable spread does exist
concerning the synoptic and, particularly, the sub-synoptic
developments for this period. Given moistening low-levels in the
presence of steepening mid-level lapse rates, it does appear that
substantial mixed-layer CAPE could develop Friday, in the presence
of strong vertical shear. This provides support for the risk of
severe storm development, though the extent and focus/details remain
unclear at the present time. Based on the latest guidance, there
does appear potential for the evolution of multiple clusters of
severe storms Friday and Friday night, with isolated to widely
scattered discrete supercell development also possible.

There does appear a consistent signal in the model output that
large-scale ascent along a strengthening mid-level baroclinic zone
may provide support for increasing thunderstorm development across
the Ark-La-Tex vicinity through southern Arkansas by mid day Friday.
As the boundary-layer destabilizes, there appears potential for
this activity to evolve into an intensifying and organizing
mesoscale convective system, which will tend to advect/propagate
eastward across the north central Mississippi/Alabama vicinity
before weakening Friday evening.

The approach of the southern mid-latitude/subtropical Pacific
impulse may contribute to renewed thunderstorm development upstream,
along the trailing convective outflow, by Friday evening. This may
evolve into another organizing cluster of severe storms, which will
probably tend to develop east-southeastward across the lower
Mississippi Valley through early Saturday.

Given the steep mid-level lapse rates, sizable CAPE and strong
shear, stronger initial storm development may be accompanied by the
risk for large, damaging hail, before activity grows upscale with
damaging wind gusts becoming the more prominent hazard, along with
the possibility of a few tornadoes.

..Kerr.. 04/08/2021

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