Lake-Effect Season Is Beginning and It's Not Just About Snow

The first step to reaching lake-effect season occurs when cold air temperatures begin to infiltrate southward over the Great Lakes and the water temperatures remain relatively warm compared to the air in the region. 

The lake waters add moisture and warmth to the cold, dry air, which results in instability and rising air, causing clouds and precipitation to develop.

In addition, winds also need to be blowing in nearly the same direction throughout the lower atmosphere, and strong wind speeds are not ideal.

For lake-effect snow, the air temperature about 5,000 feet above the ground should be at least 23 degrees Fahrenheit colder than the lake temperature. When this difference is not met, then only clouds or very light precipitation will form.

These conditions are more likely to be in place after a cold front pushes through the Great Lakes region.

(MORE: What Is Lake-Effect Snow)

As mentioned, snow is not the only event to be aware of during lake-effect season. When air temperatures are above freezing toward the surface, the precipitation that falls to the ground is rain. Sleet and graupel can also form depending on the temperatures the precipitation encounters as it falls to the ground.

Given the right conditions, thunder, heavy rainfall and waterspouts can also occur, particularly in early fall.

The temperature difference between the colder air a few thousand feet above the surface and the warmer lake water can result in enough instability for waterspouts to form.

Even when precipitation doesn't form, the increase in cloud cover can result in gloomy conditions, especially heading into November. This is the case during the fall due to the higher relative humidity values at this time of year, as temperatures cool down over lakes that are still unfrozen.

The direction of the wind plays an important role in how much and where precipitation occurs. When the trajectory of the cold air takes it along a longer path over the lake, thicker clouds can grow.

Bands of rain and snow will set up in relation to the wind direction and can result in big differences in precipitation amounts over a small distance.

One particularly noteworthy example that took place in October was the Buffalo lake-effect snow event on Oct.12-13, 2006. Just east of Buffalo, Depew and Alden received 24 inches of snow, while north Buffalo saw 20 inches. This was a memorable event due to it occurring so early in the season and because of the amount of damage that was done to trees and power lines.

Buffalo has only seen a trace of snow so far this season. However, many portions of western New York saw the first snow of the season earlier this week due to lake-effect snow.

A cold front will move through the Great Lakes Friday into Saturday and the surge of colder air will likely lead to some lake-enhanced precipitation.

Behind this front, more lake-effect rain and snow showers are possible, especially in western New York on Sunday. Little to no accumulation of snow is anticipated into early next week.