Southern Ontario: Storm Summary for Thursday, February 17 to Friday, February 18, 2022

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A snowstorm brought accumulating snowfall to much of Southern Ontario between Thursday and Friday. As part of Instant Weather’s commitment to accountability and transparency, we collected reports from our community after the storm. Thank you to everyone who submitted their report to us!

We also utilized CoCoRaHS which contains an extensive database of reported snowfall totals from all over Southern Ontario. Between the two data sources, we were able to obtain snowfall reports from many locations across the region to compare to our custom forecast. In the case that we received multiple snowfall reports for a single location, these totals were averaged together to calculate an aggregate total for that location.

With this storm, our forecast (LINK) had the potential for widespread snowfall accumulation ranging from 15-30cm with a lower amount towards the Niagara region and Central Ontario. Learning from the previous storm earlier this month, we made changes to our approach to forecasting storms like this one where temperatures are closer to the freezing mark. This tried to account for the tendency for these events to underperform the snowfall totals suggested by models due to mixing and lower snow ratios. While model data at the time showed widespread 20-30cm and even some pockets of 35cm, we went with 15-30cm and locally 30+cm. This accounted for the mixing potential while not ignoring what models were showing in case it was correct (as what happened with the January blizzard).

Based on the data, it looks like the underperformance did occur as general totals were closer to the 10-20cm range with localized pockets of 20-25cm. As a result, many areas received snowfall totals that were towards the lower end of our forecast range, but most areas were still within our range. The main area of inaccuracy in our forecast was through Deep Southwestern Ontario including Windsor and London since they saw a more prolonged period of freezing rain than expected. So Windsor for example didn’t even reach the 10cm mark in most reports that we received.

We correctly forecasted around 72% of locations while no locations reached our ‘local’ range since this event didn’t overperform. Another 24% of locations were within 5cm of our forecast range mainly in Southwestern Ontario and the GTA. Overall, the error in our forecast was 1.1cm. It does seem like our approach to changing how we forecast events with mixing has worked as our accuracy rate is above 70% despite the underperformance.

Aggregate Snowfall Reports

CREDIT: Some of the data was obtained from CoCoRaHS

City/Town Average Snowfall (CM)
Amherstburg 10.20
Aurora 24.40
Barrie 19.00
Bethany 18.00
Blenheim 4.40
Bognor 17.50
Bracebridge 9.00
Bradford 17.00
Brantford 10.00
Brighton 7.60
Brussels 11.50
Burlington 8.90
Caledonia 6.75
Cambridge 11.50
Carleton Place 16.50
Cayuga 6.40
Consecon 6.60
Creemore 14.00
Dresden 12.40
Dunrobin 12.40
Durham 11.95
Flesherton 18.50
Goderich 8.90
Guelph 14.00
Hagersville 4.10
Harrow 13.00
Holland Centre 20.00
Kanata 19.00
Kimberley 14.00
King City 16.00
Kingston 8.40
Kitchener 16.00
Komoka 15.00
Leamington 6.10
Lindsay 18.00
London 15.60
Lucknow 6.40
Merrickville 11.40
Metcalfe 23.90
Milverton 23.90
Minesing 12.00
Mississauga 10.90
Mount Albert 20.00
North York 10.90
Norwich 10.20
Oak Ridges 23.00
Oro 10.50
Owen Sound 11.45
Pakenham 25.40
Peterborough 15.00
Phelpston 12.70
Picton 8.90
Quinte West 10.75
Richmond Hill 18.00
Rocklyn 17.50
Sarnia 14.00
Scarborough 14.00
Stittsville 20.10
Strathroy 16.15
Tecumseh 5.10
Toronto 13.70
Vankleek Hill 20.10
Waterloo 16.00
Wheatley 9.90
Windsor 10.07
Woodstock 11.90