We are tracking a complex Texas low that is expected to move across the Southern Great Lakes as it weakens before strengthening over the Northeastern United States and bring a snowstorm to portions of Atlantic Canada and Southeastern Quebec.
Areas in the orange and marked with a '4' can expect snowfall totals near 15cm on average with amounts lower towards 13cm and amounts higher towards 17cm being possible. The first area extends from Eastern Hamilton near Stoney Creek and passes into the Grimsby and Albion Falls regions. Snowfall totals near 15cm are likely with lake-enhancement possibly boosting totals up to 20cm. In Eastern Ontario, this region expands from Brockville extending towards Winchester Springs, Avonmore, Alexandria, and Lancaster, including Cornwall. Snowfall amounts near or over 15cm are most likely across this region with local pockets between 15 and 25cm. Snowfall amounts between 20 and 25cm are most likely along the border with the United States and Quebec near Lancaster, Cornwall, and Morrisburg. Isolated totals up to 40cm may be possible between Cornwall and Alexandria although due to the low confidence, we have not included this on the map.
Areas in the yellow and marked with a '3' can expect snowfall totals between 10 and 15cm with pockets up to 20cm. This extends across the Hamilton and the Niagara region. Snowfall totals closest to 10cm are most likely towards the southern portion of the Niagara region while amounts closer to 15cm are possible near Lake Ontario into Hamilton. Isolated pockets up to 20cm will be possible closer to the shores of Lake Ontario for areas towards Grassie and around Grimsby. Into Eastern Ontario, snowfall totals between 10 and 15cm are likely across Prince Edward County extending into Kingston, Delta, Merrickville-Wolford, Kemptville, Chesterville, Maxville, and into Ste-Anne-de-Prescott. Local amounts near 20cm are possible across this region.
Areas in the green and marked with a '2' can expect snowfall totals between 5 and 10cm. This includes a large portion of Southern Ontario extending from Goderich through to Barrie, Bancroft, and Cobden, including everything south. This includes Ottawa, Peterborough, Toronto, London, Sarnia, and Windsor. Areas towards the north will see the lowest amounts with increasing totals as you move south. Areas near Windsor and Chatham along the shores of Lake Erie extending into Brantford and Toronto, along the shores of Lake Ontario into Oshawa and Belleville could see up to 15cm with local amounts. These increased totals will be in localized pockets only, not widespread. The best likelihood is towards the Niagara region and the United States border in Eastern Ontario.
Areas in the blue and marked with a '1' can expect snowfall totals between a trace to 5cm. Areas north of a line between Goderich, Barrie, Bancroft, and Cobden can expect snowfall totals near or under 5cm. Areas furthest south will see closer towards 5cm with the possibility of locally higher amounts near 7 or 8cm. Areas further north will see less with some areas likely to record no snowfall. This is most likely towards Parry Sound and Britt extending into Manitoulin Island, Espanola, and North Bay.
There is the potential for snow to mix with ice pellets along the shores of Lake Erie which may result in a few centimeters of lost snowfall.
Due to the timing of the heaviest snow, snow bus cancellations are possible across portions of the region on Thursday. This can be found on our website here: https://www.weatherwatcher.space/oww