Supercell-to-Bow Echo Shift Unleashes 80 MPH Winds Toward Indiana Heartland — SevereWX

An aggressive supercell southeast of Chicago is rapidly evolving into a powerful bow echo, radar showing 80-knot winds just above the ground. This beast is surging southeast at 40-45 mph into far eastern Illinois and northern/central Indiana through early evening.

Fueled by extreme instability (3000-4000 J/kg MLCAPE) and robust wind shear over 45 knots, the storm could carve a swath of 65-80 mph damaging gusts. Isolated large hail up to 1.75 inches and a tornado or two (potentially 85-110 mph) are also on the table. SPC's Mesoscale Discussion 1764 highlights the primed downstream environment in Indiana to keep this menace going strong.

Peak threats include:

• Winds: 65-80 mph
• Hail: 1-1.75 inches
• Tornado: EF1-EF2 possible

A new watch is nearly certain (95% odds) downstream of current Watch 520, covering areas from near Kankakee, IL, eastward into places like Lafayette and Kokomo, IN.

This setup echoes today's earlier storms near Lake Michigan but ramps up as it barrels into central IN. Keep an eye on radar—conditions are ripe for rapid worsening.

Stay prepared: Monitor local NWS alerts, secure outdoor items, and have a severe weather plan ready. Know your safe spot indoors away from windows.