Supercells to Batter Western Dakotas with Giant Hail, Tornadoes, Destructive Winds — SevereWX

Storms Gear Up for High-End Threats

A potent severe weather setup is taking shape across the western Dakotas into northwest Nebraska this evening. The Storm Prediction Center's latest Mesoscale Discussion (MD 1350) flags a 95% chance of a Tornado Watch as supercells fire up around 4-5 PM CDT.

A surface low near Gillette, WY, will deepen into northwest South Dakota, dragging a trough that erodes a stubborn cap. Mid-level forcing from Great Basin winds will spark widely scattered thunderstorms in a highly unstable environment—think steep lapse rates and rich low-level moisture.

Primary Hazards:

• Very Large Hail: Supercells could drop hail bigger than 2 inches, with potential for even larger stones.
• Strong Tornadoes: Low-level shear ramps up near the low, supporting a couple of intense twisters, especially in northwest SD.
• Damaging Winds: Later bow echoes in North Dakota may pack 80+ mph gusts, carving out swaths of destruction.

Initial discrete supercells in South Dakota give way to a mix of modes, including persistent hail-makers farther south into northwest Nebraska if storms ignite there.

Deep-layer shear backs north near a stalled front along the Montana border, adding some uncertainty to storm modes, but the overall threat remains robust.

Check the SPC MD graphic for the latest boundaries and stay tuned for watch updates from WFOs ABR, BIS, LBF, and UNR.

Preparedness Reminder: Review your severe weather plan, ensure multiple alert sources (NOAA radio, apps), and know your safe shelter spot. Act fast if warnings hit—time is critical with these hazards.