Heavy Rain, Snow, and Damaging Winds to End the Work Week (including Halloween)

We are watching a large and complex system that is expected to bring heavy rainfall and strong winds to portions of Southern Ontario and heavy snowfall to Northeastern Ontario for your Halloween evening into Friday, November 1st.

Significant Rainfall

Rainfall Forecast, for Southern Ontario. Issued October 31st, 2019.

Areas in orange and marked with a '4' can expect rainfall totals between 30-50mm. This region extends from Cobden through to Bancroft, Apsley and over to Lindsay and Oshawa. This area includes everything south and east towards the United States border and the Quebec border. This includes Ottawa, Brockville, Cornwall, Kingston, and Belleville. Rainfall will be heaviest throughout the early morning hours on Friday before clearing begins throughout the day on Friday. Rainfall totals may be locally higher towards the 50-70mm range due to patches of heavier rainfall. Another area of 30-60mm can be expected over the Niagara region extending from Grimsby to Port Dover. This also includes Niagara Falls and Long Point.

Areas in yellow and marked with a '3' can expect rainfall totals between 20-40mm. This region extends from the border of Quebec between Deep River and Petawawa through to areas northeast of Huntsville. This region also extends west in a line from Huntsville through to Midland, Meaford, and Owen Sound. This region also includes everything south of this line extending to the United States border and the orange region. Rainfall totals will be in the range of 20-40mm across most of the region although areas towards the northeast in the Grey/Bruce region as well as the central and northern shores of Lake Huron could receive rainfall totals towards the lower end of the scale (20-30mm) while areas further south and east towards London, Woodstock and Stratford as well as Newmarket, Lindsay and Haliburton could see totals towards the higher end of the scale (30-40mm) and have the best chance to see locally higher totals of 40-60mm. Elsewhere, local totals towards 40-60mm are possible, although less likely. A pocket of heavy rain will cross the region bringing strong winds and a changeover to snow to portions of Southwestern and Central Ontario. The rain will weaken and end beginning in the west and ending in the east.

Areas in green and marked with a '2' can expect rainfall totals between 10 and 30mm. This region extends from a line beginning over Manitoulin Island through to Key River and North Bay including Tobermory, Parry Sound, much of Algonquin Park, and Britt. Most places in this area will see between 10 and 20mm of rain although locally higher totals towards 30mm will be possible over the Bruce Peninsula extending towards Britt, Parry Sound and Burk's Falls. The lesser end of the scale can be expected over Manitoulin Island towards North Bay. The rain may mix with snow across portions of Manitoulin Island extending towards North Bay. This would reduce rainfall totals.

Areas in blue and marked with a '1' can expect rainfall totals less than 15mm. This is expected for an area from Sault Ste. Marie over to Blind River, Killarney, Monetville and West Nipissing. Rainfall totals under 10mm are likely with lesser amounts towards the north, therefore, we have excluded areas further north from the shaded portion of the map.

For those trick-or-treating, it sadly looks like a wet one. Much of Southern Ontario will be covered with a pocket of rain with only a few possible patches. These possible patches include portions of Southwestern Ontario from Central Huron-Perth Counties south to Lake Erie including Sarnia, Chatham, London and Windsor. Another pocket is throughout Central and Eastern Ontario including Parry Sound, North Bay, Britt, and Huntsville. Both these pockets are questionable and may shift as the timing approaches.


Due to the record high water levels on the Great Lakes, numerous conservation authorities have issued flood watches and watershed condition statements across our region including the GTA as well as the shores of Lake Huron and Lake Erie. The Province of Ontario has also issued flood watches across all of Southern Ontario including portions of Northeastern Ontario (Sudbury, North Bay, Manitoulin Island, and Temiskaming Shores) as well as continued a flood watch for portions of Northwestern Ontario following record rainfall through September and October, this includes Lake Superior, Kenora, Dryden, and Fort Frances.

Additional statements, watches, and warnings can be found on the Ministry of Natural Resources and Forestry's website: found here

Damaging Waves

On Lake Erie, damaging waves of 8-16 feet in height could develop over the central portion of the lake. This could strongly impact Long Point National Wildlife Area and Long Point itself with mass erosion and flooding.

On Lake Ontario, damaging waves of 3-9 feet in height could develop over the central and eastern portions of the lake. This could impact Sandbanks Park through to Wolfe Island.

Strong to Damaging *Peak* Winds

Peak Wind Forecast, for Southern Ontario. Issued October 31st, 2019.

Areas in red and marked with a '5' can expect strong to damaging peak winds gusts between 95 and 105km/h. Isolated gusts may range between 105 and 115km/h. There is some question as to whether or not stronger wind gusts are possible over Lake Erie and Lake Ontario towards 120km/h and even 130km/h, although, due to the uncertainty, we have not included this on our forecast map, despite this, it is something to watch for. This would make for significant coastal damage. This includes much of Lake Erie including Long Point and Port Dover into the Niagara region (Dunnville and Fort Erie) and possibly Niagara Falls. Over Lake Ontario, similar winds between 90 and 105km/h, locally higher between 100 and 110km/h are likely across all of Lake Ontario. This includes portions of Sandbanks Park, south of Picton through to Wolfe Island.

Areas in orange and marked with a '4' can expect strong peak wind gusts between 85 and 100km/h are possible. This includes Pelee Island and portions of Point Pelee Park and Rondeau Park. Extending inland from Lake Erie and Lake Ontario, these strong wind gusts are likely over the Delhi-Brantford-Hamilton area as well as the remaining portions of the Niagara Peninsula such as Grimsby and St. Catharines. Along the shores of Lake Ontario such as water--level Oakville, Burlington, and Toronto Island could see wind gusts in the 85-95km/h range. Extending off of Lake Ontario, wind gusts between 85 and 100km/h are possible from Gananoque and Kingston west through to Belleville, Picton, and Coburg. Over Lake Huron, wind gusts in the 85-95km/h are possible directly along the shores. This includes water-level Grand Bend, Goderich, Kincardine, and Saugeen Shores. Over Northern Lake Huron, the wind gusts between 85 and 95km/h are also possible over the Tobermory region. Finally, extending southeast of Georgian Bay, wind gusts between 85 and 95km/h are possible between Midland and Collingwood, possible extending inland just north of Barrie. It is possible that areas southeast of Lake Simcoe through to Brockville and Cornwall could receive stronger wind gusts in the 85-100km/h range IF the track of the system shifts. This is something which is not currently expected although this is something which should be monitored throughout the event incase it develops.

Areas in yellow and marked with a '3' can expect widespread peak wind gusts between 70 and 85km/h. This includes much of Southern Ontario. In Southwestern Ontario from Lake Huron through to Lake Erie and Lake Ontario, wind gusts between 75 and 80km/h are expected. This includes Windsor, Sarnia, London, Owen Sound, Kitchener, Barrie and Toronto, including everything in between. Locally higher wind gusts towards 90km/h are possible in the higher terrain throughout Southwestern Ontario (Orangeville, Guelph, and Hamilton). These isolated gusts are also possible southeast of Georgian Bay towards Midland, Barrie and, Orillia, including everything in between. Finally, in Central and Eastern Ontario, the 70-85km/h are possible from Ottawa through to Denbigh and Minden including everything south to the United States border. Locally higher wind gusts towards 90km/h are possible in the Beaverton-Lindsay region as well. Along the shores of Lake Huron and Georgian Bay in the MacTier, Bayfield Inlet, Killarney regions, including much of Manitoulin Island, wind gusts between 70 and 80km/h are possible.

Areas in green and marked with a '2' can expect peak wind gusts between 60 and 75km/h are expected. In Central and Eastern Ontario, widespread 60-70km/h are likely with highlighted higher gusts towards 75km/h. Towards Georgian Bay and Lake Nipissing, as well as Manitoulin Island, isolated wind gusts may be slightly higher towards the 70-80km/h range.

Areas in blue and marked with a '1' can expect peak wind gusts below 60km/h. These winds will cause blowing snow and could blow some Halloween decoration around.

On the map, we have included timestamps as to when the PEAK WIND GUSTS will come to an END. These can be seen at the bottom of the map. They include:

  • Friday Early Morning (2-6am): Extreme Southwestern Ontario; Windsor, Sarnia, Chatham, and Grand Bend.

  • Friday Morning (4-9am): Southwestern and portions of Northeastern Ontario; Manitoulin Island, Espanola, Tobermory, Owen Sound, Goderich, Kincardine, Stratford, London, and Port Dover.

  • Friday Noonish (11am-2pm): GTA, the Golden Horseshoe and portions of Central and Northeastern Ontario; Niagara Falls, Hamilton, Toronto, Barrie, Midland, Parry Sound, Britt, North Bay, and Temagami.

  • Friday Afternoon (11am-4pm): Central and Eastern Ontario; Peterborough, Belleville, Kingston, Bancroft, Algonquin Park, Pembroke, and Haliburton.

  • Friday Late Afternoon (3-6pm): Eastern Ontario; Ottawa, Cornwall, Brockville

Strong and gust winds will continue after these timestamps, although the peak wind gusts will have pasted after these timestamps.

It is recommended that your Halloween decorations are taken down late in the evening on Thursday to avoid any damage or property loss from the winds.

Significant Snowfall

Snowfall Forecast, for Southern Ontario. Issued October 31st, 2019.

Areas in the yellow and marked with a '3' can expect snowfall totals between 15 and 30cm. Local snowfall totals in the 30-40cm are possible, although unlikely. This region extends from the Quebec border near Temagami and Temiskaming Shores through to Sudbury. The snow may fall at moderate to heavy rates at times throughout the event, therefore, travel could be impacted along Highway 11.

Areas in green and marked with a '2' can expect snowfall totals between 5 and 15cm. This region extends from Iroquois Falls southwest through to Gogama, Elliot Lake and Blind River. This region also includes portions of Central Ontario such as Manitoulin Island, Espanola, Britt, Parry Sound and South River. Snowfall totals between 5 and 10cm are likely between Iroquois Falls and Matheson through to Gogama as well as south of Parry Sound and South River. Snowfall totals in the 10-15cm, locally in the 15-30cm are possible in and around Englehart through to Gowganda, Ruel and Sudbury including portions of Highway 11 between North Bay and Temagami as well as Manitoulin Island. In this region, the snow may fall at moderate to heavy rates which could cause travel problems along some of the roadways in the area. Some major roads include Hwy 11, 65, 118, 560, 562, 571, 567 and 805. Alongside these highway impacts, the snow would accumulate faster, therefore, allowing for more accumulations. In Southern Ontario, an area of 5-10cm is possible in Central Grey County including portions of Bruce County. This includes Markdale and areas south of Meaford, north of Shelburne and east of Hanover. This could be the first accumulating snow in Southwestern Ontario this season.

Areas in blue and marked with a '1' can expect snowfall totals less than 5cm. This includes portions of Southern Ontario to the east of Lake Huron and Georgian Bay. This includes Stratford, Wingham, Listowel, Tobermory, Owen Sound, Collingwood, Barrie, Arthur, Midland, MacTier, Gravenhurst, Huntsville, Orillia, Haliburton , Apsley, and Deep River. Snowfall should be light with most of the snow melting-on-contact. Some isolated patches of snow may accumulate on the ground. This is most likely in the Wingham-Listowel-Seaforth-Mount Forest regions of Southwestern Ontario and in the Orillia-Haliburton-Huntsville regions of Central Ontario. The remaining portions of Northern Ontario can expect 0 to 8cm of snow. In Northeastern Ontario between Blind River, Ranger Lake and Sultan, local snowfall amounts between 10-15cm are possible.

Snowfall Forecast, for Northern Ontario. Issued October 31st, 2019.

Elsewhere in Southern Ontario extending from the GTA through to Bancroft and Apsley to the east and Chatham and Windsor the west, including everything north, isolated pockets of snow may develop. The snow is not expected to accumulate and should remain melt-on-contact for these regions. Not everyone will see some. An isolated patch of accumulating snow in these unhighlighted areas is possible, although, unlikely.

This is a complex forecast with multiple elements, therefore, we will keep updated with the latest and will adjust forecasts as needed.

Last Update: Thursday Morning: 10am

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