Elevated Mixed Layer Primes Supercells for Hail, Tornadoes in Minnesota-North Dakota — SevereWX

A stalled low-level baroclinic zone stretching from north-central Minnesota into southeastern North Dakota is strengthening, setting the stage for robust thunderstorm development this evening.

As warm elevated mixed layer air aloft provides steep mid-level lapse rates and initial capping, a narrow corridor of moderate instability is building beneath strong upper-level winds. Expect south-southwesterly flow at 850 mb (30-40 kt) on the zone's western edge, combined with 50-70 kt west-southwesterly jets near 500 mb, to support organized storms—including potential supercells—starting around 7-9 PM CDT (23-01Z).

The Storm Prediction Center highlights at least a risk for severe hail, with profiles favoring 1.00-1.75 inch stones in the strongest updrafts. Damaging winds of 55-70 mph and tornadoes up to 90 mph (EF2 intensity) are also on the table. While stronger lift trails westward and the front could undercut storms, hail threats should persist into the evening before the boundary surges east with a developing wave.

This Mesoscale Discussion (1829) carries a 60% chance of a watch issuance. Impacts look focused on parts of north-central through west-central Minnesota and adjacent southeast North Dakota.

Stay prepared: Monitor radar and local alerts, secure outdoor items, and know your safe room if warnings are issued tonight.