Chadron Storms Spark Supercell Threat: 2.5-Inch Hail Looms in SD Plains — SevereWX

Chadron Storms Spark Supercell Threat: 2.5-Inch Hail Looms in SD Plains

Initial thunderstorms are bubbling up near Chadron, Nebraska, along a stationary boundary, with fresh cumulus towers popping in central South Dakota on satellite views. The SPC just issued Mesoscale Discussion 1534, highlighting an 80% chance of a severe thunderstorm watch as these storms gain steam.

A weak shortwave trough over eastern Wyoming is delivering lift, while intensifying surface heating chips away at the cap (MLCIN). Mid-level lapse rates around 7-8°C/km from recent soundings support explosive storm potential. With 40-45 kt effective shear, expect supercell structures churning out large hail up to 2.5 inches and damaging wind gusts to 70 mph. Peak threats include 1.50-2.50 inch hail, 55-70 mph winds, and isolated gusts to 90 mph.

Timing looks primed for late afternoon through early evening (around 3-6 PM CDT onward), as the nocturnal low-level jet ramps up. This could fuel upscale growth into bowing clusters, ramping up the severe wind risk east along the boundary.

Areas at risk span portions of western and central South Dakota into far northern Nebraska. Keep eyes on radar—coverage should expand quickly.

Stay prepared: Review your safe room plan, charge devices, and monitor updates from local NWS offices (ABR, FSD, LBF, UNR, CYS). Have helmets ready for hail protection and secure outdoor items against gusty winds.