Monday, April 10, 2017

A month's worth of rain in four days in Montreal

Just one of the hundreds of Quebec homes impacted by heavy rain and flooding over the weekend. Hardest hit were Sainte-Thérèse and Mirabel, but numerous other communities were impacted as well. (CTV News)
The weather across southern Quebec has gone from winter to summer in less than a week. That is fantastic, as long as you are not one of the hundreds of residents affected by flooding. The combination of very heavy rain, melting snow and ice jams has created moderate to major flooding in several regions of the province.

Trudeau Airport recorded 84.4mm of rain between April 4 and 7. The long-term normal rainfall for the entire month of April is 67.7mm. The heavy rainfall, combined with the snow melt from March storms, produced both sewer backup and river flooding. Hundreds of Quebec homes have had basements inundated with water and mud. Hardest hit to date have been the lower Laurentians, including Mirabel and Sainte-Thérèse. Numerous homes have also received flooding in Two Mountains and parts of Laval, along Lake of Two Mountains. There has even been flooding reported on the Island of Montreal. Currently, Lac St-Louis is running at record levels, 22.13 metres as of April 4th. Over the weekend, the Ottawa River was almost level with Avenue St-Charles in Vaudreuil.

Flooding north of Montreal (Global News)

Most of Quebec is currently under a flood watch as more rain is forecast. As I am writing this blog, temperatures have soared to near record highs in southern Quebec. L'Ile Perrot reached 27C (81F) at 1pm Monday, while the airport is slightly cooler at 25C (77F). The record high for the date is 26.1C (79F) set in 1945. While most of the snow is gone in metro Montreal, there is still plenty upstream, along the Ottawa River Valley and into the Laurentians. Rapid snow melt will continue to be a problem, adding to the high water levels. Vigilance is recommended near any rivers or lakes, through at least the end of the month. Cooler air is on the way for the balance of the week. Seasonable daytime highs near 10C (50F) are expected. However, rain is forecast as well. A cold front will produce scattered showers and thunderstorms tonight and Tuesday. Another 10 to 15mm of rain is expected.

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