Weather Routing For Long Distance Racing

March 18, 25 & April 1, 2021 -- 7:30 pm to 9:00 pm (Eastern)


Doing well in a long distance race such as the Bayview Mack, Chicago Mac, or TransSuperior demands teamwork, endurance, and a routing strategy based on an accurate weather forecast.  Developing a competitive routing strategy requires an understanding of basic weather forecasting principles, a familiarity with weather resources, and a working knowledge of modern routing software. This three-part 4 1/2 -hour webinar is designed for sailors who are new to long-distance racing or experienced competitors who would like to refresh their skills before the season begins.

This webinar series will cover the following topics:

  • How to interpret weather forecasting graphics.
  • The basics of wind forecasting.
  • Forecasting the development and movement of low pressure systems and their impact on the wind.
  • The basics of weather forecast models.
  • Sources of Gribs (small data file that contain weather forecast information).
  • A strategy for determining the accuracy of Grib forecast data and selecting a preferred model.
  • Preparing a marine forecast using resources from the National Weather Service and Grib files (using Squid & Expedition).
  • Weather routing using Grib data and your boat’s sailing characteristics (using Squid Sailing Software).

Don't worry if you can't attend one of the live sessions. Each session will be recorded and made available to all registered attendees until July 15, 2021.

Click here to download the weminar flyer.


Live Webinar Series

March 18, 25 & April 1, 2021

7:30 pm to 9:00 pm (Eastern)

$60 for all sessions. $45 for members of Bayview Yacht Club.

Please send questions regarding the seminar to Mark Thornton at Please click here to view the speaker's resume.

About The Presenter

Mark Thornton has been sailing for more than 25 years and currently owns Osprey, a C&C 35. His interest in weather forecasting grew from his experiences cruising and racing on the Great Lakes. Mark is a 2006 graduate of the Penn State University Certificate of Achievement in Weather Forecasting, a two-year program that develops skills in general, tropical, and severe weather forecasting.

He is the president of LakeErieWX LLC, a company dedicated to providing marine weather education and forecasting resources for recreational boaters ( Mark publishes a marine weather blog and teaches basic forecasting seminars to recreational boaters during the off-season. He has served as the Race Meteorologist for the Bayview Mackinac Race since 2014. Mark is also employed as a Teaching Assistant in the Certificate of Achievement in Weather Forecasting Program at Penn State University.