According to the Weather Network and Environment Canada, some areas of the Great Lakes region — such as those on the eastern shores of Lake Ontario, the Gulf of Georgia and Lake Erie — could be buried under 40 to 60 centimeters of snow by Sunday. “I think the real concern is going to be in the Niagara-Welland region in Ontario and, of course, Buffalo (New York), where it’s already a state of emergency,” Environment Canada senior climatologist David Phillips told CTVNews.ca. in a telephone interview Thursday. “I mean roofs can collapse under the weight of all that snow and you have power outages.” In an avalanche watch issued Wednesday night and updated Thursday, Environment Canada warned that road closures may be possible in the worst-hit areas. “Consider postponing non-essential travel until conditions improve. If you must travel, inform others of your schedule and destination and carry an emergency kit and cell phone,” the agency said. Cities and towns to the east and northeast of Lake Huron, Georgia Bay, Lake Erie and Lake Ontario have particular experience with weather systems like this, Phillips said, citing the 2014 storm that dumped more than five feet on the lake snow. Buffalo. To understand why, he said, it’s necessary to understand how lake-induced snows work. Lake-driven blizzards in Ontario and New York are most common in November and December, Phillips explained, when lower-atmosphere air and ground-level temperatures have cooled, while water in the Great Lakes it is still relatively warm. As the cold wind of late fall passes over the warm lake waters, it gathers moisture and energy to form water-laden clouds. Once these lake-induced clouds meet land, they release all that moisture, usually in the form of heavy snowfall. “The greater the difference between air temperature and water temperature, the more dangerous, stronger and more deadly storms will be,” Phillips said. The other key ingredient in the formation of lake-effect snow is the distance the wind travels over a warm lake, a factor known as “fetch.” Cold winds typically associated with lake-driven snow tend to come from the west and northwest, Phillips said. The more time these winds spend over warm bodies of water like Lake Ontario and Lake Erie, the more moisture they pull. “If the winds are going over the most water, then there’s more time for that cold air to moderate and pick up the moisture loads that are available to it, just like a sponge over a wet surface,” Phillips said. Both Lake Ontario and Lake Erie are long and narrow and stretch from west to east. This means that cold westerly winds aligned with the orientation of the lakes have a long distance to collect the moisture that later becomes snow. Phillips said that’s why communities on the eastern shores of Lake Ontario and Lake Erie – such as Buffalo, Fort Erie, Niagara Falls, Belleville and Kingston – tend to get hit hardest by the snow. caused by the lake. Finally, Phillips explained, if the winds are persistent and don’t oscillate in their passage over the land, then communities see continuous, localized snowfall over a period of days. “A lot of it is like baking a souffle — all the things have to come together to give you that perfect result,” Phillips said. “And in this case, that’s what we have: warm water, cold air and persistent winds.” Fortunately, lake-driven storms tend to become less frequent as winter progresses and the lakes freeze or at least cool. Phillips said they also don’t affect the weather systems that follow. “One storm doesn’t make another storm later,” he said. “It doesn’t really affect the weather a week or so later.”
