A blizzard warning has now been issued for south Niagara including Port Colborne, Fort Erie as well as southern parts of Welland and Niagara Falls.
Environment Canada says wind gusts could reach 100 to 120 km/h beginning tomorrow morning.
Snowfall amounts of 15 to 30 cm will spread across the area by Sunday morning but locally higher amounts are possible especially around Fort Erie as lake effect snow off Lake Erie intensifies.
Windchill values near minus 20 are also expected and a flash freeze is possible Friday morning.
Officials say visibility will be suddenly reduced to near zero at times in heavy snow and blowing snow.
They are advising people not to travel.
Also there is an increased risk of frostbite and hypothermia in the cold weather.
Pet owners should ensure that shelter is provided for pets and outdoor animals.