POST-STORM REVIEW: Snowstorm Brings Blizzard Conditions and Buries Parts of the GTHA and Eastern Ontario in Up to 50cm of Snow on Monday (Jan 17, 2022)
/
This is only an overview of some of the reports we received. A table of all 150+ locations are included at the bottom of this article.
As you likely know by now, a massive snowstorm impacted Southern Ontario earlier this week with the biggest effects being felt early Monday morning. In the end, it brought much of the Golden Horseshoe and Eastern Ontario to a standstill with many major highways being closed for hours and leaving drivers stranded. Widespread school closures delayed the start of in-person learning for many students which continued into Tuesday as road crews struggled to clear the significant amount of snow.
After the storm, we collected snowfall reports from social media and by crowdsourcing reports from our community. We received over 250 snowfall reports which represented totals for 138 unique towns and cities across Southern Ontario. Widespread totals between 40-50cm were reported across Southern Ontario with locally up to 60cm reported in the hardest-hit regions including Oshawa/Ajax and the Niagara Region. Thank you to everyone who sent us their snowfall reports! We couldn't do this without you. We tried our best to include all reports that we could find, but it’s likely that missed some reports. We extracted the data from our snowfall report form on Tuesday afternoon so any reports submitted after won’t be included in this report.
Forecast Analysis
We created an aggregate estimation for each location where we had multiple reports by using the average of the reports. This allowed us to better estimate the range of snowfall totals found within a particular area. Based on this method, the ‘winner’ of the event was Niagara on the Lake with 60cm of snowfall accumulation. However, when looking at individual reports, Oshawa comes out as the winner with 66cm of snow reported by one community member. Fifty (50) of the locations received over 40cm of snow with the average accumulation across our region ending up around 31.6cm.
Here at Instant Weather, we’re always evaluating our forecasts after each event to see how we can improve. Our goal is to continue to provide a source you can rely on and trust to provide you with accurate weather information. For this storm, we compared our final forecast map (LINK) to the 138 aggregate snowfall totals across Southern Ontario. Our forecast was considered ‘Correct’ if the reported aggregate snowfall total was within our forecasted range for that location. Note: When the aggregate snowfall total was less than 1cm away from our range we still considered it to be correct as there can be some error when measuring snow. We found that 49.6% of locations fell within our regular forecast range.
This storm ended up overperforming even the most optimistic projections so we relied more than usual on our ‘local’ range which is intended to catch the few locations that pick up more than the general forecast. This mostly occurred in the GTA and Eastern Ontario which picked up over 40cm and were above our regular forecast range. Our aim is for 15-25% of reports to fall within our local range, but with this event, we ended up with 39.4% of reports that fell within our local range.
Our forecast was incorrect in just over 10% of locations with the bulk of these locations being off by less than 10cm of snow. When looking at the average error of our forecast, we calculated the difference between the actual snowfall total and what we forecasted if the location didn’t fall within our range. This includes locations that fell within our local range so we only considered our regular forecast range. Our average forecast error for this storm was 3.5cm of snow.
Thank you so much to all those who helped us get the word out about this storm and provided us with real-time reports! You make all the difference!
Storm Timeline
Wednesday, Jan 12, 2022 (10:16 PM) - Instant Weather gives a heads up about a potential snowstorm on Sunday and Monday.
Friday, Jan 14, 2022 (5:40 PM) - Environment Canada issues the first statement regarding a potential snowstorm for Eastern Ontario and the Niagara region. The GTA wasn’t included in this first statement.
Friday, Jan 14, 2022 (7:00 PM) - Instant Weather posts an early preview of the snowstorm with the potential for over 25cm of snow.
Saturday, Jan 15, 2022 (12:03 AM) - Instant Weather provides an update based on the latest model data and says “confidence is growing for a very impactful snowstorm across Eastern Ontario and around the Golden Horseshoe with widespread totals between 20-40cm”.
Saturday, Jan 15, 2022 (4:58 AM) - Environment Canada updates Special Weather Statement calling for 20 to 35cm of snow in Eastern Ontario and the Niagara Region. (LINK)
Saturday, Jan 15, 2022 (11:18 AM) - Environment Canada upgrades Eastern Ontario and Niagara region to a Winter Storm Watch calling for up to 40cm of snow. The GTA also gets the first alert of the storm calling for 10 to 20cm of snow.
Saturday, Jan 15, 2022 (5:48 PM) - Instant Weather talks about the potential for some locations to get up to 50cm of snow according to our free app.
Saturday, Jan 15, 2022 (10:16 PM) - Instant Weather posts our first detailed forecast of the event calling for locally over 40cm of snow for Eastern Ontario and Niagara Region.
Sunday, Jan 16, 2022 (4:55 AM) - Environment Canada starts upgrading parts of Eastern Ontario to a Winter Storm Warning with up to 50cm of snow possible. A snowfall warning is issued for the GTA calling for between 15-20cm of snow. Special Weather Statement is issued further west for Muskoka, Orillia and K/W for 5 to 15cm of snow.
Sunday, Jan 16, 2022 (11:01 AM) - Instant Weather posts an update saying that the GTA and Hamilton appear likely to see 20-40cm of snow.
Sunday, Jan 16, 2022 (4:35 PM) - Environment Canada updates Snowfall Warning for the GTA calling for locally up to 25cm. (LINK)
Sunday, Jan 16, 2022 (5:29 PM) - Instant Weather posts their final forecast of the event calling for widespread 20-40cm and locally up to 50cm of snow.
Sunday, Jan 16, 2022 (6:48 PM) - Two hours later, Environment Canada revises the Snowfall Warning for the GTA again mentioning locally up to 30cm of snow. (LINK)
Sunday, Jan 16, 2022 (9:03 PM) - Environment Canada upgrades the GTA to a Winter Storm Warning with between 20-30cm of snow. Snowfall warnings are issued for Orillia and Guelph with totals near 15cm. Barrie gets the first advisory of the event calling for 5-15cm of snow.
Sunday, Jan 16, 2022 (10:34 PM) - Instant Weather forecasts an ‘Impactful Blizzard’ around the Golden Horseshoe and into Eastern Ontario. Advises against non-essential travel during the morning.
Sunday, Jan 16, 2022 (10:46 PM) - Environment Canada updates Winter Storm Warning around the GTA calling for up to 35cm of snow. (LINK)
Sunday, Jan 16, 2022 (11:06 PM) - Environment Canada updates Snowfall Warning for Orillia/Guelph with 15-20cm of snow possible. (LINK)
Sunday, Jan 16, 2022 (11:16 PM) - Instant Weather talks about the potential for 40+cm of snow throughout the GTA based on the latest data.
Sunday, Jan 16, 2022 (11:38 PM) - Environment Canada updates Winter Storm Warning for the Niagara region with locally up to 50cm of snow possible. (LINK)
Monday, Jan 17, 2022 (2:08 AM) - Instant Weather says confidence is growing in 40-50cm of snow for the GTA.
Monday, Jan 17, 2022 (5:08 AM) - Environment Canada issues the first Blizzard Warning of the event for the Niagara Region.
Monday, Jan 17, 2022 (6:46 AM) - Environment Canada updates Winter Storm Warning around the GTA for 25cm to 40cm of snow. (LINK)
Monday, Jan 17, 2022 (6:51 AM) - Environment Canada adds areas further west including Orillia through K/W to 15-25cm of snow. (LINK)
Monday, Jan 17, 2022 (7:06 AM) - Environment Canada issues Snowfall Warning for the City of London calling for near 15cm of snow.
Monday, Jan 17, 2022 (7:15 AM) - 30cm of snow is reported in Downtown Toronto.
Monday, Jan 17, 2022 (7:45 AM) - Blizzard Warning is issued for the rest of the Golden Horseshoe and into Eastern Ontario calling for up to 40cm.
Monday, Jan 17, 2022 (8:21 AM) - Environment Canada upgrades the K/W and Guelph area to a Winter Storm Warning calling for 25 to 35cm of snow.
Monday, Jan 17, 2022 (8:39 AM) - Environment Canada updates the Blizzard Warning for the GTA mentioning the potential for up to 50cm of snow. (LINK)
Monday, Jan 17, 2022 (9:00 AM) - Eastern Ontario is added to the Blizzard Warning.
Monday, Jan 17, 2022 (9:13 AM) - Environment Canada increases the expected snowfall for the GTA to 40-60cm. (LINK)
Monday, Jan 17, 2022 (AM) - Blizzard conditions and rapid snowfall accumulation brings the GTA to a standstill and turns many major highways into a parking lot. Clean-up continued into Tuesday which resulted in 2 to 3 days of school closures throughout the affected area.
Aggregate Snowfall Reports
Note: To cut down on redundancies, we merged some smaller neighbourhoods and boroughs into the associated city/town.
| City/Town | Average Snowfall (CM) |
|---|---|
| Acton | 23 |
| Ajax | 51.25 |
| Alcona | 34 |
| Alliston | 25 |
| Almonte | 48 |
| Amherstview | 16.25 |
| Ancaster | 40 |
| Arnprior | 39 |
| Ayr | 37.5 |
| Balderson | 44 |
| Baltimore | 50 |
| Bancroft | 45 |
| Barrie | 25.5 |
| Beeton | 20 |
| Belleville | 33.7 |
| Bowmanville | 49.5 |
| Bracebridge | 19 |
| Bradford | 30.4 |
| Brampton | 37 |
| Brantford | 26 |
| Buckhorn | 41 |
| Burlington | 41.2 |
| Caledon | 20 |
| Cambridge | 24.5 |
| Cameron | 50 |
| Carleton Place | 46 |
| Chalk River | 12.5 |
| Chatham | 2.75 |
| Coldwater | 23 |
| Collingwood | 15 |
| Courtice | 46.7 |
| Deep River | 17.5 |
| Dundas | 32 |
| Dunnville | 30 |
| Elgin | 37 |
| Etobicoke | 48.3 |
| Fergus | 20 |
| Fergusonvale | 25 |
| Fonthill | 52 |
| Georgetown | 19 |
| Glencoe | 2 |
| Grimsby | 44.7 |
| Guelph | 22.3 |
| Hamilton | 43.4 |
| Hanover | 0.25 |
| Hastings | 45 |
| Havelock | 48 |
| Holland Landing | 30 |
| Jordan Station | 36 |
| Kanata | 42 |
| Keswick | 36.5 |
| Kilbride | 28 |
| Kincardine | 0 |
| Kingston | 34.75 |
| Kitchener | 29 |
| L'Amable | 43 |
| Lakefield | 42.5 |
| Leamington | 0 |
| Limerick | 36.5 |
| Lindsay | 40.7 |
| Lisle | 20 |
| London | 14.7 |
| Loretto | 22 |
| Lucknow | 0 |
| Markham | 58 |
| Maynooth | 39 |
| Millbrook | 46 |
| Millgrove | 30 |
| Milton | 37 |
| Mississauga | 41 |
| Monkland | 30 |
| Mount Albert | 40 |
| New Tecumseth | 24 |
| Newmarket | 36.75 |
| Niagara Falls | 49 |
| Niagara on the Lake | 60 |
| Nobleton | 35.5 |
| Norfolk County | 35 |
| North Bay | 0 |
| North Dumfries | 25 |
| North Frontenac | 45.5 |
| North York | 39.8 |
| Norwood | 38 |
| Oak Ridges | 43 |
| Oakville | 44 |
| Omemee | 35 |
| Orangeville | 21.95 |
| Orillia | 22 |
| Orleans | 46 |
| Oro-Medonte | 25 |
| Oshawa | 54.4 |
| Ottawa | 49 |
| Owen Sound | 0 |
| Peterborough | 45.25 |
| Pickering | 48 |
| Port Hope | 57 |
| Port Rowan | 43 |
| Powassan | 2 |
| Queensville | 37.5 |
| Quinte West | 28 |
| Richmond Hill | 37 |
| Rockwood | 14 |
| Roseneath | 52 |
| Rothsay | 3 |
| Sandford | 41 |
| Scarborough | 47.2 |
| Sebringville | 13 |
| Simcoe | 28.97 |
| Smiths Falls | 49.5 |
| St. Catharines | 50.3 |
| St. Marys | 12 |
| Stayner | 15 |
| Stittsville | 44 |
| Stoney Creek | 46.7 |
| Stouffville | 33 |
| Stratford | 7 |
| Strathroy | 0 |
| Sunderland | 35.5 |
| Tavistock | 26 |
| Tilbury | 0 |
| Tillsonburg | 36.3 |
| Toronto | 43 |
| Trenton | 41.2 |
| Tweed | 41.5 |
| Uphill | 13 |
| Uxbridge | 33.75 |
| Valentia | 38 |
| Wainfleet | 48 |
| Wallaceburg | 0 |
| Warminster | 30 |
| Waterdown | 37 |
| Welland | 48.4 |
| Wendover | 22 |
| Wheatley | 2 |
| Whitby | 46 |
| Windsor | 0 |
| Woodstock | 30.7 |
