Warm Lake Temperatures


Onshore winds from Lake Superior early or very late in the snow season can inhibit accumulation by melting the snow or at least retarding accumulation after the snow reaches the ground. The warming is abruptly reduced a short distance inland due to adiabatic cooling that occurs as air rises up the hill. When air rises it expands and cools to balance off the warming. Based on the dry adiabatic lapse rate, unsaturated air cools 5.37 degrees Fahrenheit per 1000 feet as it rises. Once saturated, the air cools generally half as much. Latent heat released when the water condenses is the process that reduces the cooling.


More on lapse rates from AMS Glossary of Meteorology:
Dry Adiabatic Lapse Rate
Moist Adiabatic Lapse Rate