An Extreme early spring weather event across the Central Upper Peninsula of Michigan: Microburst to a foot of Snow

A potent early spring storm affected Michigan’s Upper Peninsula on 9-11 April 2017. This dynamic storm produced 80-mph straight-line winds, followed by nearly a foot of heavy wet snow. Numerous swaths of trees were uprooted across Iron and Marquette Counties, as a pocket of intense winds caused tornado-like damage during the night of 9 April from Republic to Negaunee, Michigan. As the cleanup process was underway, temperatures struggled to reach the freezing mark on 10 April, making for a frigid work environment for those restoring power. In fact, 24 hours after the convective storms, drifts of pea size hail remained in some locations. This powerful spring storm then dumped 8-12’’ of wet, heavy snow on the morning of 11 April across communities hit hard by the damaging convective winds. This further complicated restoration of power and cleanup.

While severe weather and the subsequent snowstorm were predicted, the combined impacts to the restoration of power were unexpected. This presentation will examine the complex meteorology and communication challenges of this event. This event is an important reminder that impacts from one event during transition seasons can be exacerbated by a subsequent high-impact weather event with significant implications on impact-based decision support services.