ROCHESTER, N.Y. – It has been a long, hard winter and the combination of nearly daily snowfall, strong winds, and bitter cold can be a big challenge. Speaking from personal experience, it can wear you down over time.

We know that much of our seasonal snowfall is due to the lake effect. But did you know that about 50 percent of our seasonal snow is due to this “snowmaking machine” we call Lake Ontario? Conversely, if we did not have the Great Lakes, Rochester would have much less snow to have to contend with. By now, most of us know the basic ingredients for the development of lake snow. The water temperature has to be significantly warmer compared to the air crossing the lakes. In the case of this week’s event, the water temperature of Lake Ontario is in the mid-30s, but the airmass above it is in the teens and the single digits. As a result, that relatively warm moist air tends to rise just like a hot air balloon. And that moisture is then deposited downstream with the wind direction being a big influence on who gets to shovel all that snow.

However, not all of these lake-effect snow events are the same. First, quite often there can be just a single intense band of lake snow. Usually, this type of squall is orientated west to east along the long geographic axis of Lakes Erie or Ontario. Places like Watertown or Buffalo can see huge amounts of accumulation with snowfall rates in the range of two to four inches per hour. Second, there is a multiple-band event which is not quite as intense. This can still produce a significant amount of snow over a larger geographic area. In this case, the wind is now orientated in a more north-to-south direction. This gives the cold air a shorter distance to cross the lakes and consequently less time to gain moisture. However, do not be fooled. This type of lake snow is still a problem in terms of visibility and difficult travel.

For the News10NBC First Alert meteorologists, it is a major challenge to forecast these moving and migrating bands of lake of snow. An analogy for this movement is like watching windshield wipers on your car. The squalls can move back and forth across Western New York and make for a long, hard winter season.