Snowstorms headed to Southern Ontario this week are shaping up to be potentially worse than initially anticipated, with meteorologists now warning of two severe back-to-back weather events that will hammer portions of the province with up to 40 cm of wintry precipitation.

The treacherous conditions are set to kick off on Wednesday, when a Texas low will shift into southern and northeastern Ontario, bringing with it heavy, slow, freezing rain and sleet that could spell disaster for commuters and air travellers.

Power outages are possible, said The Weather Network (TWN) on Tuesday morning, adding that localized lake-effect snow will creep into areas around Sarnia, Kincardine, Hamilton, Oakville and more by early Wednesday afternoon, and quickly become more fierce as the evening wears on.

A swath of the province stretching from just north of Windsor, across London, and encompassing the above-listed cities and towns along with Barrie, Bancroft, Coburg, Toronto and more will experience bursts of the white stuff amounting to 1-3 cm overnight.

And by Thursday, things will get even messier.

Toronto could be hit with over 30 cm of snow before the weekend is overhttps://t.co/Im80fykUGv

— blogTO (@blogTO) February 10, 2025

As temperatures gradually drop, winds are expected pick up, creating potentially whiteout conditions with the newly-fallen snow.

"The strongest winds will blow over the Niagara region, and eastern sections of Lake Ontario, where gusts could reach between 70-90 km/h," TWN cautions. "The combination of gusty winds, wet snow, and icy conditions could result in power outages throughout the day."

Between the two days, heavy ice accumulations are expected around Lake Erie, and snowfall totals will amount to a staggering 20-40 cm in the worst areas — at rates of 5 cm per hour — including in cottage country.

Ottawa, too, will see some of the highest snowfall amounts of potentially over 30 cm.

The bulk of Southern Ontario, including GTA locales like Pickering, Oshawa, Hamilton, Brampton, and Toronto proper, are due to be hit with double-digit amounts of accumulation, from 15-20 cm in the downtown core to 20-25 cm in Newmarket and further north.

St. Catharines seems to be getting off the easiest with 10-15 cm accrued from Wednesday afternoon to Thursday — still enough of a hazard.

Environment and Climate Change Canada (ECCC) issued a special weather statement on Tuesday afternoon, likewise advising of "snow, ice pellets and freezing rain likely late Wednesday afternoon into Thursday" in Toronto with "snowfall amounts possibly exceeding 15 cm and poor visibility in heavy snow."

The Weather Network's latest outlooks for snow across the region in the next couple of days.

"There's high confidence that hazardous travel conditions are likely Wednesday evening into Thursday morning. Drivers are urged to consider postponing non-essential travel until conditions improve," TWN's experts say, adding that this midweek nastiness will be a precursor to another snowstorm moving in next weekend.

Double-digit snowfalls of 10-15 cm are expected on the Saturday and Sunday before Family Day, with freezing temps of the minus teens on the holiday itself and extending into colder-than-usual conditions in the weeks to come.