Stalled Boundary Fires Up Supercells for Hail, Tornadoes in Minnesota-North Dakota — SevereWX

Evening Severe Threat Brewing in Upper Midwest

A stalled low-level boundary across north central Minnesota into southeastern North Dakota is set to spark strong thunderstorms by 7-9 PM CDT. The SPC's Mesoscale Discussion 1829 highlights a 60% chance of a watch as supercells become possible.

Key Threats:

• Hail: Up to 1.75 inches in stronger storms.
• Winds: 55-70 mph gusts.
• Tornadoes: Potential for EF2 intensity (up to 90 mph).

Beneath steep mid-level lapse rates and a capping elevated mixed layer, moderate instability is building along the boundary's western edge. A 30-40 kt low-level jet and 50-70 kt upper-level winds will aid organized storm development, favoring supercell structures despite some undercutting risk from the front.

Even if storms form on the cooler side of the boundary, thermodynamic profiles should support large hail into the evening before the front surges east with a developing wave.

This setup targets parts of north central through west central Minnesota and adjacent southeast North Dakota. Activity peaks through 10 PM CDT.

Stay Prepared: Monitor radar closely, have multiple alert sources, secure outdoor items, and know your safe room. Evening timing means more people at home—don't get caught off guard. Check SPC updates for watch issuance.