‘Formidable’ lake effect snow band could slam parts of Upstate NY this weekend

Syracuse, NY – The first real taste of winter could bring “formidable” lake-effect snow to parts of Upstate New York this weekend, the National Weather Service said.

More than a foot of lake effect snow is possible in the typical lake effect areas near Lakes Erie and Ontario.

“Formidable lake-effect snow bands and flurries will develop east and southeast of the Great Lakes, resulting in significant accumulations and drifting snow in the hardest hit areas,” the weather service said.

The worst places are probably I-90 between Cleveland and Buffalo and I-81 north of Syracuse. Winds gusting up to 30 mph will cause poor visibility on the roads.

“Travel may be very difficult to impossible with very poor visibility and deep snow on the roads,” the weather service office in Buffalo said. “Some major roads may temporarily close.”

Winter storm watches will be in effect for the areas from Friday morning to Sunday morning. The watch areas include Cattaraugus, Chautauqua, Wyoming and southern Erie counties in western New York, south of Buffalo; and Oswego, Lewis and Jefferson counties on the Tug Hill plateau.

On Monday, the wind may change and come from the northwest. If that happens, the lake effect snow could reach all the way from Georgian Bay to central New York and even the Southern Tier, the weather service said.

The exact positions of narrow lake effect snow bands are very difficult to predict several days in advance.

The end of November and the beginning of December is the best snow season for the lake effect because the Great Lakes are still warm and mostly ice-free. Cold winds blowing down from Canada scoop up moisture from the warm lakes and drop it as snow as the wind blows over relatively colder land.

Lake Erie’s water surface temperature is 51 degrees today, 6 degrees above the long-term average for November 27th. Lake Ontario is also 51 degrees, but the weather service doesn’t keep historical data. That’s because Lake Ontario is so deep — up to 800 feet — that cold water rising under strong winds causes the temperature to fluctuate widely at the weather service’s official measuring site near Rochester.

The surface temperature of the Great Lakes is an important ingredient for snow effect on the lake, but not the only one. To generate blizzards with large lake effects, the wind must come from the west or northwest, and the air blowing over the lakes must be cold enough.