Flood potential increasing in southern Quebec

Several families near Carignan south of Montreal, had to be evacuated over the weekend as a result of spring flooding along the L'Acadie and Richelieu Rivers. 
(CBC News)

Urgence Quebec as well as local authorities across the Townships, Beauce and into the Monteregie, are keeping on eye on several rivers including the L'Acadie, Richelieu and Yamaska for flooding. Already over the weekend several families had to be evacuated near Carignan on the South Shore as a result of ice jam flooding on the L'Acadie River. Canadian Coast Guard hovercraft have been breaking ice on both the Yamaska and Chateuguay Rivers for several days. As expected the region has rapidly made the jump from severe cold and snow to spring warmth. The result has been a rapid decrease in snowpack as well as sharp rises on area rivers breaking up thick ice.

To add to this worsening scenario was nearly 20mm of rain on Friday and the arrival of another moisture laden system this evening into Tuesday. Low pressure over Texas will move towards the Great Lakes and down the St. Lawrence Valley on Tuesday. After sunshine and warm highs of close to 13C Monday in Montreal, clouds will thicken rapidly this evening. Rain, heavy at times, is forecast to develop this evening and taper to showers Tuesday morning, lows near 5C and temperatures not much warmer Tuesday. Expect 25-35mm, over one inch of rain for the region. This will increase runoff adding to the concern for flooding. A heavy rain warning has been issued by Environment Canada as well as a flood watch by Urgence Quebec for the southern portion of the province. In Montreal and especially flood prone Laval, area rivers are slowly rising but are still considered normal. Behind the system on Wednesday we can expect blustery conditions with perhaps a snowflake or two and much colder highs of 4C.