Chicago Mac: The 2017 One-Two Punch

By any measure, the 2017 Chicago Yacht Club Race to Mackinac was no picnic.

The Race started on Saturday under very pleasant southwesterly breezes and the fleet made good progress toward Mackinac Island. However, as the fleet worked north, two weather features delivered a one-two punch that prompted nearly a third of the competitors to withdraw from the Race.

The first feature was a heat burst, a rare thunderstorm event that ravaged the fleet with 50 knot downburst winds near Milwaukee late on Saturday evening. The second feature was the passage of a cold front down Lake Michigan on Sunday.

Based on a review of the weather pattern and tracking data from YP Tracking, it appears the brisk northerly winds and the resulting steep waves following the passage of the cold front were responsible for many more retirements than the wind from the rare heat burst on Saturday evening.

The timing of the cold front’s passage, as well as the speed of the wind and wave heights, was well forecast. Over the course of many hours, the combination of strong winds and relentless waves took their toll on boats and crew, and the one-two weather punch won’t soon be forgotten.

Mark Thornton, whose company LakeErieWX LLC provides marine weather education and forecasting resources, has published a thorough review of what happened. To relive the race and prepare for the 2018 edition on July 21 … click here.