KITCHENER -- A snowfall warning is in effect Waterloo Region and Wellington County as 15-25 cm of snow is expected to fall on Sunday.

Environment Canada first issued a special statement Saturday afternoon to the area and several others across Southern Ontario, including Toronto, Hamilton, Huron-Perth, Oxford-Brant, London-Middlesex, and Halton-Peel.

At the time, the agency said only 5-10 cm was expected, but increased the amount to 7-14 cm in a Sunday morning update as well as issued a travel advisory.

Around 12:30 p.m., the snowfall warning was in effect and the estimated amount was increased to 15-20 cm before another increase to 15-25 cm just before 2 p.m.

Roughly 7-11cm of snow had already been observed between London and Guelph by noon.

The significant snowfall is now expected to fall throughout the day and late into the night.

Motorists should be prepared for slippery roads, low visibility, and rapidly accumulating snow, according to the agency.

Those closer to Lake Ontario may experience rain or ice pellets closer to the evening.