Canada's top ten weather stories of 2013
- 2013 - A Year in Review
- 1. Alberta's Flood of Floods
- 2. Toronto's Torrent
- 3. Bumper Crops in the West, So-So for the Rest
- 4. The Nightmare during Christmas
- 5. To Flood or Not to Flood?
- 6. Rebound in the Arctic Ocean and the Great Lakes
- 7. Wicked Winter Weather Wallops the East
- 8. Spring Flooding in Ontario’s Cottage Country
- 9. Prairie Winter Went on Forever
- 10. Stormy Seas and Maritime Tragedy
- Runner-up Stories
- Atlantic Regional Highlights
- Quebec - Regional Highlights
- Ontario - Regional Highlights
- Prairie Provinces - Regional Highlights
- British Columbia - Regional Highlights
- The North - Regional Highlights
8. Spring Flooding in Ontario’s Cottage Country
A burst of spring weather in mid-April pushed temperatures into the 20s across southern and central Ontario. The unseasonably warm and unstable air triggered Canada’s first tornado of the season on April 18 around Shelburne, Ontario. More significantly, the warm, moist air led to major flooding north and east of Georgian Bay in Ontario’s cottage country. In addition, copious amounts of warm rain melted a later-than-normal snowpack in Algonquin Park and the surrounding woodland. With rain coming down in torrents − nearly 90 mm in two days − steam billowed from the ground. The ensuing melt water and rains funnelled quickly into rivers, lakes and streams causing some of the highest and fastest rising water levels in recent memory – as much as 3 m in 24 hours. At one dam in the Kawarthas flood waters sped at a rate of 8,700 m3/s – vastly more powerful than the previous record rate of 5,200 m3/s. It was estimated that river volumes exceeded a 100-year occurrence.
Authorities quickly declared states of emergency in eight regions across central Ontario from the south end of Algonquin Park to the Kawartha Lakes, including the towns of Huntsville, Bracebridge, Haliburton and Bancroft. The flooding forced evacuations, with 1,000 residents being displaced in Bracebridge alone. Hundreds more were trapped in their homes by surrounding water. The fast-rising waters breached dams sending crushing ice into boat houses and docks, and inundating dozens of properties under a metre of water. Scores of streets, roads, culverts and highways in several mid-Ontario towns were flooded. And a huge sinkhole on Highway 11, south of Huntsville, forced traffic to detour. During the worst of the flood, the popular Deer Lake Resort Park was nearly three-quarters underwater. Power was shut off for several days as a safety precaution. The resulting damages totalled several millions of dollars.
The historic flood was due to a combination of partially frozen ground, later-than-usual snowmelt, persistent lake ice and, largely, heavy warm rains over two or more days. Before temperatures shot above 20°C, early spring temperatures were averaging as much as five degrees colder than normal. That left the still frozen ground unable to handle the sudden overflow of water. A protracted warm spell in the final two weeks of April saw temperatures climb two and a half degrees warmer than normal. Just north of Bracebridge, a weather station in Beatrice, Ontario with a 137-year record lost almost 48 cm of snowpack in three weeks before nearly 100 mm of rain soaked the region over three days, including 55 mm on the 18th – the wettest April day ever. The total monthly rainfall of 169 mm also set a new April record.
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