Summary (tl;dr)

Multiple regions around the Great Lakes are currently under "lake effect snow warnings" due to heavy snowfall, significantly reduced visibility, and hazardous travel conditions caused by cold air moving over the relatively warmer lake waters.

Essential Background

Lake effect snow is a localized weather phenomenon that occurs when cold air masses move across the unfrozen, warmer waters of large lakes. As the cold air passes over the lake, it picks up moisture and warmth, creating narrow bands of clouds that then deposit heavy snowfall on the downwind (leeward) shores. This process is particularly common in the Great Lakes region during late fall and winter months.

The Full Story

As of mid-December 2025, "lake effect snow warnings" are trending as several areas surrounding the Great Lakes are experiencing significant snowfall and difficult conditions. In Northeast Ohio, Lake Effect Snow Warnings are in effect for counties including Ashtabula, Cuyahoga, Geauga, and Lake, with forecasts predicting 5 to 10 inches of snow and strong winds causing blowing and drifting snow. Western New York, specifically southern Erie, Chautauqua, and Cattaraugus counties, is also under a Lake Effect Snow Warning, with 4 to 12 inches of snow expected, particularly in higher terrain east of Lake Erie. Central and upstate New York, especially east of Lake Ontario, including Oswego, Wayne, northern Cayuga, Onondaga, Madison, and southern Oneida counties, have faced or are currently under warnings, with Oswego County anticipating up to 14 inches of snow by Sunday. Across the border, parts of Ontario, Canada, such as Simcoe, Grey, and areas near Lake Superior including Sault Ste. Marie, Searchmont, Montreal River Harbour, Batchawana Bay, and St. Joseph Island, are experiencing snow squalls with accumulations ranging from 10 to 35 cm, leading to hazardous travel and highway closures.

Why It Matters

The issuance of lake effect snow warnings is crucial because these events can rapidly create dangerous travel conditions, including sharply reduced visibility, snow-covered roads, and blowing snow, which increase the risk of accidents. Beyond travel disruptions, heavy snowfall can also lead to power outages and make daily activities exceptionally difficult, posing risks to public safety and impacting local infrastructure and economies.

Geographic Location

• Ashtabula County, Ohio, United States (Lake Effect Snow Warning, 5-10 inches of snow expected)
• Cuyahoga County, Ohio, United States (Lake Effect Snow Warning, 5-10 inches of snow expected)
• Geauga County, Ohio, United States (Lake Effect Snow Warning, 5-10 inches of snow expected)
• Lake County, Ohio, United States (Lake Effect Snow Warning, 5-10 inches of snow expected)
• Southern Erie County, New York, United States (Lake Effect Snow Warning, 4-12 inches of snow expected)
• Chautauqua County, New York, United States (Lake Effect Snow Warning, 4-12 inches of snow expected)
• Cattaraugus County, New York, United States (Lake Effect Snow Warning, 4-12 inches of snow expected)
• Oswego County, New York, United States (Lake Effect Snow Warning, 6-14 inches of snow expected)
• Wayne County, New York, United States (Lake-Effect Snow Warning, 5-10 inches of snow expected)
• Northern Cayuga County, New York, United States (Lake-Effect Snow Warning, 5-10 inches of snow expected)
• Onondaga County, New York, United States (Lake-Effect Snow Warning, 6-12 inches of snow expected)
• Madison County, New York, United States (Lake-Effect Snow Warning, 6-12 inches of snow expected)
• Southern Oneida County, New York, United States (Lake-Effect Snow Warning, 6-12 inches of snow expected)
• Simcoe County, Ontario, Canada (Snow Squall Warning, 10-20 cm of snow expected)
• Grey County, Ontario, Canada (Snow Squall Warning, 10-20 cm of snow expected)
• Sault Ste. Marie, Ontario, Canada (Snow Squall Warning, 20-35 cm of snow expected)
• Searchmont, Ontario, Canada (Snow Squall Warning, 20-35 cm of snow expected)
• Montreal River Harbour, Ontario, Canada (Snow Squall Warning, 20-35 cm of snow expected)
• Batchawana Bay, Ontario, Canada (Snow Squall Warning, 20-35 cm of snow expected, Highway 17 closures)
• St. Joseph Island, Ontario, Canada (Snow Squall Warning, 20-35 cm of snow expected)
• Wawa, Ontario, Canada (Highway 17 closures due to snow squalls)