Southern Ontario is bracing for a storm of epic proportions, and the forecast just got even worse with threats of rare winter lightning and snowfall that could exceed the 30 cm mark in parts of the region.

The region has flirted with major snow events in recent weeks, ranging from light dustings to heavy (but fast-melting) snowfall, however, this weekend's storm seems to be the real deal.

A massive low-pressure system now intensifying over the Great Lakes is expected to cause chaos across the region when it strikes on Friday evening, including the potential for major traffic slowdowns in the Greater Toronto Area and disruption at local airports.

According to The Weather Network, snow is expected to arrive just in time for the evening rush hour commute on Friday, and will worsen throughout the evening.

Different areas of southern Ontario can expect varying levels of accumulation between Friday evening and Saturday morning. Most of the region will likely wake up to coverage in the range of ten to over 20 cm of snowfall on Saturday, though some areas further west, like Orangeville, may break the 30cm mark.

Other areas of Ontario to the east, like Bancroft east into Ottawa, may see totals in the 20-25 cm range.

'Massive and powerful' weekend snow storm could slam Toronto area with 20 cm https://t.co/DtzWbSdmgT

— blogTO (@blogTO) January 10, 2024

Toronto will be spared from the worst of the storm, though Environment and Climate Change Canada (ECCC) has placed the city under a Weather Advisory, cautioning of "Locally heavy snowfall with total accumulations of 5 to 10 cm."

Regardless of the totals, that snow is expected to show up in force. ECCC warns of peak snowfall rates of up to five cm per hour in Toronto, with the potential for strong gusts of wind up to 70 km/h and blowing snow to reduce visibility and cause havoc on roads.

Similarly, The Weather Network describes the potential for "blizzard conditions" across the GTA with whiteout conditions across the broader region.

The Weather Network notes that these conditions could affect more than just commuters, warning the public to "expect flight delays and cancellations" and suggesting "localized wind damage and power outages are also possible."

Joining the heavy snowfall, this system is expected to bring a rare winter thunderstorm, known as 'thundersnow' to the region.

Conditions will transition into rain and scattered flurries in Toronto through Sunday, which will be followed by an extended deep freeze that will feel as cold as -19 C in the city.