Rain washing away snow in Ottawa with up to 25 mm possible

Ottawa is being doused by a rainstorm that could raise water levels and create a risk of flooding.

Environment Canada’s forecast shows 15 to 25 mm is expected ending Wednesday night. Depending on fluctuating temperatures, precipitation could freeze at the ground level making for icy roads and sidewalks.

“Temperatures should quickly rise above zero, and the rain will continue through Wednesday,” the weather agency notes.

Yesterday snow mixed with ice pellets appeared in the afternoon, with rain switching overnight.

Most of the rain is coming on Wednesday with Environment Canada noting it will be around 6 C. Thursday’s warm temperatures will continue, but cooler weather is expected to return by Friday.

The excess rain will be difficult for the ground to absorb, and with melting snow, it could cause some areas to flood, the weather agency’s website reads.

Because of the conditions, the Rideau Valley Conservation Authority issued a flood outlook statement for the Rideau River. Levels are reportedly normal for the Lower Ottawa River.

The Mississippi Valley Conservation Authority issued a water safety statement for its watershed for the risk of high flows, unsafe banks and melting ice.

“No flooding is anticipated at this time, although rainfall can cause ice jams to occur along smaller rivers and creeks. This can cause water levels to rise rapidly without warning,” the statement reads.

Similarly, there is a flood outlook statement issued from the South Nation Conservation Authority on Wednesday morning.

“Early notice of the potential for flooding based on weather forecasts calling for heavy rain, snow melt, high wind or other conditions that could lead to high runoff, cause ice jams, lakeshore flooding or erosion,” it reads.