US, Canada: Storm system to bring heavy snowfall and strong winds to portions of the US and Canada through early Dec. 26 /update 2

Event

A potent storm system will bring snow to portions of the Appalachia, Great Lakes, and Ohio Valley regions of the US, as well as Ontario, and Quebec in Canada through early Dec. 26. The affected areas include Michigan near Lake Huron, western New York, western Pennsylvania, eastern Ohio, West Virginia, eastern Kentucky, southwestern Virginia, western North Carolina, and eastern Tennessee. As of the afternoon of Dec. 24, snow is falling across eastern Ohio, eastern Kentucky, and eastern Tennessee in the US while rain is falling farther east. Forecast models indicate rain is expected to change to snow is expected to change over to snow in the coming hours from west to east. There is also likely to be a period of sleet and freezing rain in western Pennsylvania, northeastern Ohio, southeastern Ontario, and central Quebec. Lake-effect snow will persist near Lake Erie, Lake Huron, and Lake Ontario through late Dec. 25 or early Dec. 26. Some uncertainty remains in the forecast track of the system and projected snow amounts are subject to changes over the coming days.

Government Advisories
As of Dec. 24, the US National Weather Service (NWS) has issued winter storm warnings for New York, Pennsylvania, and Ohio along lakes Erie and Ontario, northeastern and southern Ohio, the Laurel Highlands of Pennsylvania, West Virginia, eastern Kentucky, southwestern Virginia, eastern Tennessee, and far western North Carolina. Additionally, Environment Canada has issued snowfall and freezing rain warnings across southern Ontario and central Quebec. Authorities will likely issue new alerts or update/rescind existing advisories as the winter storm transits the region over the coming days.

Hazardous Conditions
The latest forecast guidance indicates that accumulations of 30-50 cm (12-20 inches) of snow are expected in the hardest-hit areas, including portions areas along the coasts of lakes Erie, Ontario, and Huron. Accumulations of 15-30 cm (6-12 inches) are expected across the Appalachian Mountains in the eastern US, as well as eastern Ohio and southeastern Ontario, including the Greater Toronto Area. Lower amounts of 5-10 cm (2-6 inches) are expected farther east and south within the affected area where there will be a more prolonged period of rain and/or freezing rain. In addition to the heavy snow, strong wind gusts are likely lead to periods of blowing and drifting snow. Blizzard conditions are possible. Sporadic power outages are likely throughout the affected area.

Transport
The inclement weather will likely cause widespread ground and air transport disruptions across the affected area through early Dec. 26. Traffic and commercial trucking delays are possible along regional highways including the I-40, I-64, I-70, I-71, I-75, I-76, I-77, I-79, I-80, I-81, I-86, I-90, and I-99 corridors in the US, as well as the Trans-Canada Highway, Macdonald–Cartier Freeway, and Alexander Graham Bell Parkway in Canada. Difficult and potentially dangerous driving conditions are also likely on secondary and rural roadways in the affected states as maintenance crews prioritize clearing major routes. Authorities could close stretches of highway if driving conditions become too hazardous. Gusty winds may threaten to topple high-profile vehicles throughout the affected area. Heavy wet snow and strong winds could bring down power lines and trees with foliage. Flight delays and cancellations are likely due to ground stops and deicing operations at regional airports including, but not limited to, those serving Toronto (YYZ), Pittsburgh (PIT), Cleveland (CLE), Columbus (CMH), and Buffalo (BUF).

Advice

Monitor local media for updated weather information. Verify road conditions before driving in areas where heavy snowfall is forecast. Allow extra time to reach destinations in these areas and carry an emergency kit and warm clothes if driving is necessary, especially on secondary or rural routes that could become impassable. Plan accordingly for delivery delays if routing shipments by truck through the affected area through at least early Dec. 26. Confirm flights. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

US National Weather Service
US Road Conditions
Meteorological Service of Canada