D3 disco
...Most of the area from the mid MO Valley into the TN Valley...
A classic, progressive deep-layer cyclone will interact with a
increasingly unstable air mass to produce widespread wind damage
beginning near the KS/MO and OK/AR borders during early afternoon,
and expanding northeast across much of MO, IA, IL, IN, western KY
and parts of western TN through evening. Not only will extreme wind
field favor damaging winds, but profiles will also favor supercells
capable of fast-moving tornadoes, whether a broken line or in QLCS
fashion along surging outflows. The steep lapse rates and rapid
changes overall will also support strong tornado potential
interspersed with the damaging wind area. Last, cells will also
produce hail over northern areas where temperatures aloft are cold.
...MS/AL/TN Overnight...
As the upper wave departs to the north, mid to perhaps upper 60s F
dewpoints will surge north across MS, western AL and the western FL
Panhandle during the evening and overnight. As mentioned, height
falls will be maintained due to the secondary wave moving into TX.
The result will be a persistent 50-60 kt low-level jet beneath 60 kt
midlevel southwesterlies, and increasing boundary-layer moisture.
This regime is likely to support scattered thunderstorms after 06Z,
and the overall environment conditionally supports strong tornadoes.
The severe risk will only increase into Saturday/D4. As such, have
extended the Enhanced Risk farther south across MS and western AL.