The Arctic cold front is forecast to move out of the East and Gulf Coasts through the weekend, as a cold high-pressure system settles over the Plains and Ohio Valley.

This will bring freezing temperatures well below -17.7°C (0°F) across the Upper and Middle Mississippi Valley and Ohio Valley, according to the National Weather Service. The system is driven by the polar vortex and has prompted multiple winter weather alerts across the country.

It will generate heavy lake-effect snow along the coastlines of Lake Erie and Lake Ontario during the weekend. This will bring heavy snow and dangerous to near-impossible travel conditions to parts of New York, Ohio, and Pennsylvania on Sunday, prompting lake effect snow warnings across the three states.

New York

Lake-effect snow warnings remain in effect across multiple counties in western and north-central New York through Sunday into early Monday, as persistent snow bands continue downwind of Lakes Erie and Ontario.

In western New York, the warning is in effect until 07:00 EST Monday for Chautauqua, Cattaraugus, and southern Erie counties, including Jamestown, Olean, Orchard Park, and Springville.

Heavy lake-effect snow totals of 15–30 cm (6–12 inches) are forecast in parts of the warning area. Gusts of up to 56 km/h (35 mph) will bring blowing and drifting snow, reducing visibility.

Across north-central New York, a Lake Effect Snow Warning is in effect for northern Cayuga County from 04:00 EST Sunday to 04:00 EST Monday, with the greatest accumulations expected north of Cato and near Fair Haven. Snowfall totals of 18–36 cm (7–14 inches) are forecast, with intense snowfall rates reaching 5–7.5 cm (2–3 inches) per hour Sunday morning through midday.

Farther east of Lake Ontario, Oswego County remains under a Lake Effect Snow Warning until 16:00 EST Sunday. Additional snowfall of 25–50 cm (10–20 inches) is expected in the most persistent bands, with extreme snowfall rates of up to 7.5–10 cm (3–4 inches) per hour through Sunday morning. Wind gusts up to 56 km/h (35 mph) will lead to blowing and drifting snow, producing near-zero visibility at times and making travel dangerous.

Lake-effect snow warnings also remain in effect until 13:00 EST Sunday for Jefferson and Lewis counties, including Watertown and Lowville.

Snow accumulations of 18–36 cm (7–14 inches) are forecast, with the highest totals across far southern Jefferson and far western Lewis counties. Gusty winds will further reduce visibility and create hazardous travel conditions on snow-covered roads.

Ohio

A Lake Effect Snow Warning is in effect until 07:00 EST Monday for counties across northeastern Ohio. These include Ashtabula Inland, Ashtabula Lakeshore, Cuyahoga, Geauga, Portage, and Lake counties.

Heavy lake-effect snowfall totals of 8–23 cm (3–9 inches) are forecast across the warning areas.

Travel will be hazardous due to icy roads and visibility dropping to less than 0.4 km (0.25 miles) through Sunday. Snow squalls with heavy snowfall rates of 2.5–5 cm (1–2 inches) per hour will create whiteout conditions at times, making travel impossible.

Pennsylvania

Lake-effect snow warnings are in effect for areas north of I-90, including northern and southern Erie counties and Crawford County, until 07:00 EST Monday. The warnings are also in effect for Mercer, Venango, McKean, and Warren counties for the same period.

Snowfall totals of 8 – 25 cm (3 – 10 inches) are forecast through Sunday, with wind chills below -17.8°C (0°F) persisting in parts of the warning areas.

Lake-effect snow squalls around Lake Erie are expected to make travel conditions difficult along parts of I-90 through Sunday afternoon. Snowfall rates of 2.5 – 5 cm (1 – 2 inches) will create near-whiteout and impossible travel conditions at times, especially in higher terrain inland from Lake Erie.

Slippery roads due to accumulating snow will create difficult travel conditions across the region.