We are currently tracking a system that will track south of Southern Ontario which will bring some light snow to much of the region with some lake-enhanced amounts to the west of Lake Ontario.
Blue or '1':
Areas in the blue or marked with a '1' can expect less than 5cm of snow. This will include areas along the far northern side of the system. This include Kincardine, Wingham, Barrie, Orillia, Woodview, Apsley, Plevna, Fenelon Falls, Macdoc, Sharbot Lake, Smiths Falls, Alexandria, Cornwall, and Brockville. Areas which may see locally higher amounts include Goderich, Wingham, Shelburne, Mount Forest, Lindsay and Peterborough. These areas can expect around 5cm although local amounts towards 10cm are possible.
Green or '2':
Areas in the green or marked with a '2' can expect between 5 and 15cm of snow. This includes much of the Extreme South and portions of the GTA, Southwestern Ontario and Central Ontario. Areas which are likely to see around 5cm but may see upwards of 10cm include Goderich, Wingham, Shelburne, Mount Forest, Lindsay and Peterborough. Areas which may see between 5 and 10cm include Bayfield, Listowel, Arthur, Orangeville, Newmarket, Belleville, Kingston, Picton, Brighton, Windsor, Pelee Island, Chatham and Rondeau Park. Local amounts of 10 to 12cm are possible. Areas likely to see between 6 and 12cm with local amounts towards 15cm include Sarnia, London, St. Thomas, Delhi, Long Point, Dunnville, Cambridge, Kitchener, Toronto, Oshawa, and Brampton. Isolated pockets of 14 to 18cm are possible between Kitchener, Woodstock and Dunnville although the risk is too low to include into the 'yellow' region or area marked with a '3'.
Yellow or '3':
Areas in the yellow or marked with a '3' can expect between 10 and 20cm of snow. This includes much of the Western GTA extending into the Golden Horseshoe. Snowfall totals between 12 and 16cm are possible over areas between Guelph and Brantford, including Fort Erie. Snowfall totals between 14 and 18cm are possible over portions of Mississauga, Oakville, Burlington, Hamilton, Grimsby and Niagara Falls. As these totals are higher than elsewhere, it's important to mention that this is due to lake-enhancement in lake-effect snow bands. Therefore, because of the localized nature of these bands, the difference of 10 kilometers could change amounts of 8 to 12cm to 14 to 18cm. Snowfall amounts between Burlington and Grimsby, including Hamilton could locally overachieve to amounts between 15 and 25cm although the risk is quite low.
Disclaimer: This forecast is working off the the higher possible numbers. Multiple places could ‘underachieve.’