Countdown to the 110th CYC Race
to Mackinac - July 21, 2018




Email the Regatta Manager

Click here to email the Regatta Manager with any questions or information.

Join Our Mailing List


June 25 Safety Thursday - The Climatology of Lake Michigan

 Safety Thursday - The Weather of Lake Michigan

By Mark Thornton - LakeErieWX


Sailing and weather are intrinsically linked. Experienced Mac sailors understand that developing a pre- race weather forecast and monitoring its evolution on the racecourse is an important strategic and safety aspect of participating in the Chicago Yacht Club’s Race to Mackinac. Misjudging the wind forecast can quickly send you to the back of your fleet, while failing to properly assess the risk for severe weather can unnecessarily jeopardize the safety of the crew.

This Safety Thursday article is the first of a two-part series and focuses on the climatology of Lake Michigan and typical conditions for the middle of July. This is a great way to start thinking about the forecast and your weather strategy.

Since this article is so graphics-heavy, rather than replicating it here, please go to The full text of the article along with all graphics are available there.

Next Week’s Article will cover more practicalities of developing a forecast and monitoring conditions during the race.

About the Author
Mark Thornton began sailing on Lake Erie in 1994 and he currently owns Osprey, a 1985 C&C 35. His interest in weather forecasting grew from his experiences racing and cruising on the lake. In addition to sailing and weather forecasting, Mark maintains a website devoted to Great Lakes meteorology ( and enjoys publishing summaries of interesting Great Lake weather events and teaching basic weather forecasting skills to sailors.

Questions regarding this article are encouraged and should be directed to

Note: The purpose of this article is to highlight some of the Mac Safety Regulations and how your crew can race the Mac as safely as possible. As always, ultimate responsibility for the safety of the crew and the decision whether to race or to stop racing is that of the skipper (RRS4, MSR2). This email is meant as a courtesy only and you should always refer to the Race Documents section of the website for the Notice of Race, Sailing Instructions and Mac Safety Regulations, which govern the race.


Chicago Yacht Club


Team One





Star Line

Copyright © 2018 Chicago Yacht Club. CYC