Mark Thornton

Mark Thornton is widely recognized as one of the leading marine weather authorities on the Great Lakes. With nearly 30 years of sailing experience and a deep passion for weather science, Mark brings a unique blend of practical knowledge and academic expertise to his teaching.

He is the founder and president of LakeErieWX, a company dedicated to providing marine weather education, forecasting, and routing services tailored specifically for Great Lakes boaters. Through LakeErieWX and GLCCSchool, Mark has helped thousands of recreational mariners better understand and anticipate the weather conditions that affect their time on the water.

Mark holds a Certificate of Achievement in Weather Forecasting from Penn State University - a rigorous program focused on general, tropical, and severe weather forecasting. He spends much of summer on his Maineship 34 Pilot Downeast Trawler, and continues to refine his forecasting skills while actively cruising the Great Lakes.

Whether you're a seasoned sailor or just starting out, Mark’s courses offer invaluable insights that can enhance your safety, confidence, and enjoyment on the water.

Upcoming classes

Great Lakes Weather 1: Marine Weather Basics
Marine Weather Basics is the first course in GLCCSchool’s four-part Marine Weather Essentials series, designed specifically for Great Lakes boaters. It’s available as a standalone class or as part of a specially priced bundle.
Great Lakes Weather 2: Forces Controlling The Wind / Using Doppler Weather Radar
This second class in GLCCSchool’s Marine Weather Essentials series reveals the forces that shape wind patterns across the Great Lakes. You’ll learn how terrain, temperature, and pressure systems influence wind behavior - and how to use Doppler radar to monitor developing weather in real time. Available individually or as part of a discounted four-class bundle.
Great Lakes Weather 3: Weather Makers … Forecasting High & Low Pressure Systems
In the third installment of the series, you’ll explore the powerful role of high and low pressure systems in shaping Great Lakes weather. Learn to identify and interpret cold fronts, warm fronts, and occluded systems using surface charts and forecast tools. Take this class on its own or enjoy savings with the full four-part package.
Great Lakes Weather 4: Thunderstorm Primer / Creating Your Own Marine Forecast
The final class in the Marine Weather Essentials series prepares you to recognize and respond to thunderstorm threats. You’ll learn how to spot storm types, understand their development, and use online tools to create your own daily marine forecast. Register individually or save with the complete four-part series.