June 25 Severe Weather Threat

A weak frontal boundary is expected to drift southeastward this afternoon, and be roughly situated across central Minnesota into eastern South Dakota. This boundary, combined with other subtle boundaries from convection last night will provide several potential areas for development of thunderstorms this afternoon. Southerly surface winds will continue to push moisture into the state ahead of the slowly moving boundary. Dewpoints are expected to reach into the upper 60s, and lower 70s throughout. This moisture return combined with strong heating with highs expected in the upper 80s and even lower 90s will provide strong instability. This instability will lead to strong updrafts, and quickly developing storms this afternoon. Shear values are not expected to be sufficient for strong rotating storms, but supercells are still likely due to the amount of instability.

With thunderstorms developing along/near the surface boundaries this afternoon, expect storms to move off slowly to the southeast. With the strongest storms, the potential for very large hail (>2") is there, however, expect the main threats with the storms to be heavy rain, lightning, strong winds, and large hail. More updates are possible this afternoon if severe weather becomes likely, or if any drastic changes are made in the forecast. For now, be prepared for thunderstorms this afternoon, but also be ready for a beautiful day beforehand with highs in the upper 80s and mostly clear skies.