Boundary Supercells Ignite Severe Fury Across IL-IN-KY-TN — SevereWX

Storms are exploding along a differential heating boundary from southeastern Illinois into far southwestern Indiana, western Kentucky, and far northern middle Tennessee. SPC's latest Mesoscale Discussion (1746) flags these cells rapidly maturing into supercells amid sky-high instability—over 6000 J/kg MLCAPE—and 40 knots of effective shear.

Echo tops are pushing 55,000 feet with signs of rotation already. Low-level shear (200 m²/s² 0-3 km SRH) boosts the odds for persistent supercells, severe hail (1-1.75 inches), damaging winds (55-70 mph), and a few brief tornadoes (up to 85-110 mph). Storms crossing the boundary could tap even richer spin for localized twisters.

A watch issuance looks probable within the hour (80% chance), valid through around 7 PM CDT. This setup stands out from earlier MCS wind chatter—now it's discrete supercell mayhem.

Key Threats:

Monitor radar closely as cells evolve. Have your severe weather plan ready: identify shelter, charge devices, and stay tuned to local NWS updates. Safety first in this primed environment.