This is an updated forecast post from the one issued between 12pm and 2pm on Tuesday, December 10th, 2019.
This forecast is for the same event although the validation period has been shortened from Tuesday through Friday to Wednesday through Friday. This will be displayed on the forecast maps, most evident across Southwestern Ontario (Huron-Perth-Wellington-Dufferin-York-Durham areas).
There are some slight changes in location between this forecast and the one issued earlier which are explained in each forecast region.
You can view the original forecast here: https://www.weatherwatcher.space/post/multi-day-snow-squall-outbreak-across-the-great-lakes
We have made numerous localized maps for these snow squalls. Scroll down in the article to find the map which best fits your region.
Niagara:
Changes with this forecast:
- Shifted the the 10-15cm from Fort Erie and Crystal Beach north to Niagara Falls and Welland
- Extended the St. Catharine and Dunnville cm further north towards Niagara Falls and Welland
- Removed the 5-10cm from Southwestern Ontario (Listowel-Guelph-Monkton)
Brief heavy flurries will develop along the shores of the Lake and extend north before creating a snow squall from Kingston/Eastern Ontario into Long Point. This snow squall will shift south throughout the morning before moving over the lake in the early afternoon.
Areas in the yellow and marked with a '3' can expect snowfall totals between 10 and 15cm. This extends from Niagara Falls and Black Creek through to Welland, Long Beach, and areas just south of Dunnville. Local snowfall amounts up to 20cm are possible within just a few hours.
Areas in the green and marked with a '2' can expect snowfall totals between 5 and 10cm. This extends from between St. Catharines and Niagara Falls through to Dunnville and Long Point Park where 5-10cm is likely. There will be a sharp cutoff between no snow and up to 10cm, therefore, areas in the green should note that you may see no snow at all. Areas along the shores of Lake Erie near Fort Erie over to Crystal Beach could see a quick 10cm as the snow squall shifts back south of the region over Lake Erie into New York State. Local amounts near 15cm are possible in this area if the squall can linger just one or two additional hours.
Elsewhere, areas in blue and marked with a '1' can expect snowfall totals between a trace or 0 to 5cm.
Prince Edward County:
Changes with this forecast:
- Shifted the track of the Prince Edward County snow squall south over Lake Ontario
- Extended the Prince Edward County snow squall into Eastern Ontario along the US border
- Updated Central Ontario (Kawartha Lakes-Dongola-Lake Dalrymple) to better reflect the expected squall location
Note: Refer to the Southwestern Ontario forecast for information on the Kawartha Lakes-Lake Dalrymple-Minden squalls.
Areas in the green and marked with a '2' can expect snowfall totals between 5 and 10cm. This extends from Sandbanks into Picton, Kingston, Port Milford, and Gananoque where 5-10cm is expected. The lowest amounts will be towards the north near Picton and Sandbanks with the most near Port Milford. This area also extends along the New York border including Mallorytown, Brockville and even Prescott. Snowfall amounts near 5cm are likely with 10cm possible if the squall can become 'somewhat' stationary over the region.
Elsewhere, areas in blue and marked with a '1' can expect snowfall totals between a trace or 0 to 5cm.
Southwestern Ontario (Parry Sound-Tobermory South):
Changes with this forecast:
- Limited snowfall totals across Southwestern and Central Ontario for areas like Huron-Perth-Grey-Wellington-Dufferin-Southern Simcoe-York-Durham-Eastern Haliburton
- Lowered snowfall totals across the Bruce Peninsula
- Updated the heavy snow regions to better align with expected squall locations north of Orillia and Midland and south of Parry Sound
Areas in the red and marked with a '5' can expect snowfall totals between 20 and 30cm with local amounts between 30 and 40cm. This includes two defined regions. The first region including and south of Parry Sound extending to areas near Huntsville and MacTier, including Rosseau and Iifracombe. A second band also extends for areas north of Midland and Orillia over Washago, Honey Harbour, Severn Falls, and Lake Dalrymple.
Areas in the orange and marked with a '4' can expect snowfall totals between 15 and 20cm. This extends across the southern areas of the Bruce Peninsula between Wiarton, Cape Croker, and Kemble. Snowfall totals near 15cm are likely here. Areas towards the east between Brooks Landing towards Emsdale, Swindon, Huntsville, MacTier, Port Carling, and Torrance. Snowfall totals between 15-20cm are expected with local totals between 25 and 30cm are possible. Areas further south between and including Midland, Longford, and Victoria Road. Isolated totals near 25cm are possible.
Areas in the yellow and marked with a '3' can expect snowfall totals between 10 and 15cm. This includes much of the Bruce Peninsula extending south towards Owen Sound and Southampton as well. Isolated totals near 20cm are possible on the Bruce Peninsula as well, mainly towards the orange (4) region. In Central Ontario, snowfall totals between 10-15cm, locally 20cm, are possible for areas south of Midland such as Balm Beach extending into Orillia, Lagoon City, Kawartha Lakes, Norland, Gravenhurst, Bracebridge, Baysville, Southwestern Algonquin Park, Dunchurch, Bayfield Inlet and Britt.
Areas in the green and marked with a '2' can expect snowfall totals between 5 and 10cm. This is expected from Lucknow and Amberley through to Hanover, Markdale, Chatsworth, and Kincardine. Snowfall amounts near 5cm are likely with local amounts towards 10cm likely. In any stationary squall in this region, snowfall totals near 15cm are possible. In Central Ontario, 5-10cm are possible for areas from Elmvale through to Baywood Park, Gamebridge, Fenelon Falls, Minden, Haliburton, and Dorset. Most places will see between 7 and 12cm across this region with less towards Southern Simcoe County and more towards Muskoka and Haliburton. Around 5cm is likely across much of Manitoulin Island with up to 10cm near South Baymouth and the eastern shores as well as a band across the central-western portion of the island.
Elsewhere, areas in blue and marked with a '1' can expect snowfall totals between a trace or 0 to 5cm.
Central Ontario (Parry Sound-Tobermory North):
Changes with this forecast:
- Lowered snowfall totals across the south (south of Markdale-Hanover-Barrie)
- Lowered snowfall totals across Manitoulin Island and the Bruce Peninsula
- Updated snowfall areas to better align with expected snow squalls over Manitoulin Island and Central Ontario
Areas in the red and marked with a '5' can expect snowfall totals between 20 and 30cm with local amounts between 30 and 40cm. This includes three separate regions. The first region is in Northern Ontario along the shores of Lake Superior. Areas from Batchawana Bay through to Montreal River Harbour and Agawa Bay can expect snowfall totals near 25 and 30cm with local amounts towards 35-45cm. Areas in Central Ontario between Parry Sound, Emsdale, Huntsville, Swords, and MacTier can expect snowfall totals between 20 and 30cm with local totals between 30 and 40cm. This includes Rosseau and Ilfracombe. Finally, a narrow band will develop and become stationary for areas just north of Midland through to Washago, Honey Harbour, Severn Falls, and Lake Dalrymple.
Areas in the orange and marked with a '4' can expect snowfall totals between 15 and 20cm. This extends across the southern areas of the Bruce Peninsula between Wiarton, Cape Croker, and Kemble. Snowfall totals near 15cm are likely here. Areas towards the east between Brooks Landing towards Emsdale, Swindon, Huntsville, MacTier, Port Carling, and Torrance. Snowfall totals between 15-20cm are expected with local totals between 25 and 30cm are possible. Areas further south between and including Midland, Longford, and Victoria Road. Isolated totals near 25cm are possible. In Northern Ontario, this includes areas just north of Heyden along Highway 17.
Areas in the yellow and marked with a '3' can expect snowfall totals between 10 and 15cm. This includes much of the Bruce Peninsula extending south towards Owen Sound and Southampton as well. Isolated totals near 20cm are possible on the Bruce Peninsula as well, mainly towards the orange (4) region. In Central Ontario, snowfall totals between 10-15cm, locally 20cm, are possible for areas south of Midland such as Balm Beach extending into Orillia, Lagoon City, Kawartha Lakes, Norland, Gravenhurst, Bracebridge, Baysville, Southwestern Algonquin Park, Dunchurch, Bayfield Inlet, Britt and Port Loring. Across Manitoulin Island, there is a band of near 10cm likely from Silver Water through to Sheshegwaning into areas just east of Spanish. In Northern Ontario, this includes Searchmont and Heyden as well as the northern portions of Sault Ste. Marie. Snowfall totals near 10cm are most likely with 10-15cm for areas surrounding Heyden.
Areas in the green and marked with a '2' can expect snowfall totals between 5 and 10cm. In Central Ontario, 5-10cm are possible for areas from Elmvale through to Baywood Park, Gamebridge, Fenelon Falls, Minden, Haliburton, Dorset, Powassan, and Monetville. Most places will see between 7 and 12cm across this region with less towards Southern Simcoe County and more towards Muskoka and Haliburton. Around 5cm is likely across much of Manitoulin Island with up to 10cm near South Baymouth and the eastern shores as well as a band across the central-western portion of the island. This region also includes Killarney and Espanola. In Northern Ontario, this includes Sault Ste. Marie and Ranger Lake.
Elsewhere, areas in blue and marked with a '1' can expect snowfall totals between a trace or 0 to 5cm.
Northern Ontario:
Changes with this forecast:
- Increased snowfall totals for areas east of Lake Superior
- Lowest snowfall totals for areas east of Lake Nipigon
- Removed the light flurries across Northwestern Ontario
Note: Refer to the Central Ontario forecast for information on the Manitoulin-Parry Sound-Britt squalls.
Areas in the red and marked with a '5' can expect snowfall totals between 20 and 30cm with local amounts between 30 and 40cm. This extends from Lake Superior Park through to Agawa Bay, Montreal River Harbour, Batachawana, and Goulais Bay. Snowfall totals will average near 25 and 30cm. Areas near Montreal River Harbour towards Batchawana Bay could see local amounts between 35 and 45cm with other places seeing local amounts between 30 and 40cm.
Areas in the orange and marked with a '4' can expect snowfall totals between 15 and 20cm. This extends around the red region and includes areas just north of Heyden along Highway 17.
Areas in the yellow and marked with a '3' can expect snowfall totals between 10 and 15cm. This region includes Searchmont and Heyden as well as the northern portions of Sault Ste. Marie. Snowfall totals near 10cm are most likely with 10-15cm for areas surrounding Heyden.
Areas in the green and marked with a '2' can expect snowfall totals between 5 and 10cm. This is expected over Beardmore as well as areas slight north, south and east. General snowfall amounts between 6 and 12cm are likely in this region. Around 5cm is likely across much of Manitoulin Island with up to 10cm near South Baymouth and the eastern shores as well as a band across the central-western portion of the island. This region also includes Killarney and Espanola. This also includes Sault Ste. Marie and Ranger Lake.
Elsewhere, areas in blue and marked with a '1' can expect snowfall totals between a trace or 0 to 5cm.
We will continue to monitor the situation and update as needed.
There is the risk of road closures and school closures over the next few days so make sure to frequent check out social media pages for updates forecasts and live-report information.
This information including our snow day forecast can be found on our website here: https://www.weatherwatcher.space/oww