1.25-Inch Hail, 70 MPH Gusts Forecast in Evolving SD-NE Supercells — SevereWX

Supercells are firing up across central South Dakota, with storms poised to push into northern Nebraska amid a setup ripe for severe hazards.

Storms have initiated near a pocket of rising mid-level air motion over the central and northern Plains. After morning thunderstorms cleared out, sunshine has fueled temperatures into the 80s F with dewpoints near 70 F. This has sparked moderate atmospheric instability—MLCAPE of 1000-2000 J/kg—paired with 20-30 kt deep-layer shear and veering winds favoring rotating supercell structures.

Initial storms could pack large hail to 1.25 inches (half-dollar size) and damaging wind gusts. As the afternoon progresses, models indicate storms will cluster, heightening damaging wind risks into the evening.

The Storm Prediction Center highlights an 80% chance of issuing a Severe Thunderstorm Watch this afternoon (valid through 8 PM CDT) to cover these threats. Peak expectations include wind gusts of 55-70 mph, hail to 1.25 inches, and isolated tornadoes up to 90 mph.

Key Threats:

This MD (1802) underscores a transition from discrete supercells to a wind-focused cluster, warranting vigilance in the affected polygon from central SD southward into northern NE.

Stay weather-aware: Review your severe weather plan, monitor radar and local NWS updates, and have a safe shelter ready if storms approach.