We are currently watching scattered lake-effect snow development across Lake Huron and Georgian Bay before intensification and organization this (Thursday) evening. Heavy snow with peak rates between 4-8cm/h with totals near and possibly over 40cm being possible from the event.
Areas in red and marked with a '5' can expect snowfall totals between 20 and 40cm of snow with local snowfall totals near 50cm. As snow squalls develop over areas east of Central/Northern Lake Huron, organization is expected to occur. These snow squalls will develop in the morning before shifting south throughout the day on Thursday. Into the afternoon, organization is expected with a strong snow squall or two extending from the Goderich area inland as well as the Grand Bend area inland. Over the Grand Bend area, inland including Bayfield, Parkhill and Exeter, snowfall totals between 25 and 35cm are likely. If the band can remain stationary for an extended period of time, total snowfall amounts between 35 and 50cm are possible in this region. Depending on the exact location of the band when it begins to be stationary (at least somewhat), it could shift this region further south or north. Areas south towards Forest and Watford should monitor the location of this strong snow squall Thursday evening. The heaviest snow will fall at rates of 4-8cm/h, possibly stronger and occur overnight into Friday. Along the direct-shores of Lake Huron, snowfall totals may be reduced due to the nearby lake temperatures.
Areas in the orange and marked with a '4' can expect snowfall totals between 15 and 30 with local amounts towards 35cm. This area extends along the shores of Lake Huron extending inland towards London. This region includes Amberley, Goderich and Lucan, as well as Clinton and Hensall. As the snow squalls shift south and begin to organize, the squall will be largest over this region with the potential for multiple small bands of snow squalls. This would extend from Amberley south towards Goderich and from Goderich inland towards Lucan. As described above, the exact location of the organizing may change, therefore, this region may shift a few kilometres south or north. Most regions should see between 15 and 25cm of snow although the hardest hit could see between 25-35cm. Snowfall rates will peak between 3-7cm/h in the evening extending into the overnight. Along the direct-shores of Lake Huron, snowfall totals may be reduced due to the nearby lake temperatures.
Areas in the yellow and marked with a '3' can expect snowfall totals between 10 and 25cm. Most of the highlighted places will see between 10 and 20cm although local amounts near 25cm are possible towards London and south of Georgian Bay with isolated totals near 30cm. For areas east of Lake Huron towards Kincardine, Saugeen Shores and Lucknow can expect between 10 and 20cm of snow. Areas towards London near Komoka and Northern London, snowfall totals between 10 and 25cm are possible. For areas south of Georgian Bay between Owen Sound through to Meaford, Stayner and Singhampton can expect between 15 and 25cm of snow, locally 30-40cm. Along the direct-shores of Lake Huron and Georgian Bay, snowfall totals may be reduced due to the nearby lake temperatures.
Areas in the green and marked with a '2' can expect snowfall totals between 5 and 15cm. This includes between Lake Huron and Georgian Bay extending inland. Towards the north, this includes Lion's Head, Wiarton, Collingwood, Shelburne, Markdale and Sauble Beach. Snowfall totals will range between 10 and 15cm in this range with 5 to 10cm over the Bruce Peninsula. Further south towards Wingham, Listowel, Mildmay, St. Marys and Glanworth, including Strathroy, snowfall totals between 5 and 10cm are likely. For areas near the west such as Glanworth and Wingham, snowfall totals may be slightly higher towards the 10-15cm range.
Areas in the blue and marked with a '1' can expect snowfall totals less than 10cm. For much of the highlighted areas, snowfall totals less than 5cm are expected. Over portions of Grey County near Hanover and Simcoe County near Angus can expect snowfall totals towards 10cm are possible. In the Niagara region towards Fort Erie and the Parry Sound region towards Britt, southwest winds will begin to push into the region beginning later in the day on Friday, local snow squalls may develop into Saturday and could locally produce up to 10cm. Isolated pockets of 15cm are possible towards Britt extending to Lake Nipissing, although this will be brief. In Eastern Ontario, lingering flurries are likely to produce less than 5cm.
Road closures are possible to the east and southeast of Lake Huron as well as some bus cancellations and school closures on Friday across the region, specifically around the Goderich/Grand Bend/London regions. We will have a weather day outlook issued between 8pm and 12am on our website in the Weather Day section. We will also be posting our school day closure information there Friday morning if there are any closures.