Ontario...up to 25 cm of snow ...minus 20 deg C

Thursday morning's commute could be slower in parts of Ontario as a low-pressure system brings heavy, fluffy snowfall. Parts of the GTA and the 401 corridor could see accumulations of up to 25 cm. Weather alerts are also in place for snow squalls in some areas. This increase in snowfall is driven by a strengthening upper-level low tracking south of Lake Erie and Lake Ontario, enhancing snowfall rates and totals. Snowfall rates of 1-2 cm/h are expected for the GTA and parts of eastern Ontario overnight, continuing into early Thursday morning.

Blustery winds accompanying the system may lead to blowing and drifting snow, reducing visibility at times. Lake-enhanced and lake-effect snow squalls could create higher accumulations in snowbelt regions. Temperatures in southern Ontario will steadily drop throughout Wednesday as well. A significant cooldown is expected, with temperatures falling by 10-15°C between Wednesday and Thursday.

Overnight into Thursday, colder air will spread, bringing daytime highs in the minus double digits. Wind chills could make it feel closer to the -20s. Another surge of Arctic air is forecast to push south, keeping cold conditions entrenched well into next week. Arctic air will take hold next week, bringing lake-effect snowsqualls to snowbelt regions east and southeast of Lake Huron and Georgian Bay.

Environment Canada