Manitoba issues heavy rainfall advisory, as much as 100 millimetres of rain expected for southwestern Manitoba and Saskatchewan

Manitoba Infrastructure and Transportation’s Hydrologic Forecast Centre issued a heavy rainfall advisory on Monday, noting that a significant rainfall – as much as 100 millimetres of rain – is forecast for parts of southwestern Manitoba and Saskatchewan in the next three to four days.

While various weather forecasts indicate variable amounts and different areas where the precipitation will fall, “if the maximum forecasted rainfall amount occurs, it could generate potential overland flooding and raise river levels across much of southwestern Manitoba,” the advisory warned.

The Shellmouth Dam is currently at the “summer target level” and the Qu’Appelle River has a slightly higher than normal flow for this time of the year, the Hydrologic Forecast Centre said in a press release. “However, soils are generally much drier than 2014 when a similar heavy rain event led to issues with flooding, so it is anticipated the effects will not be as serious,” the release noted.

Flash or overland flooding could happen in areas hit by heavier rainstorms. “Detailed impacts on tributaries and main stem rivers will be evaluated as a clearer picture of this active weather emerges,” the advisory noted, adding that communities in southwestern Manitoba are advised to take necessary precautions.

Rainfall amounts will vary depending on stronger thunderstorms, which will be “embedded in the larger area of rain. Current indications are for the heaviest band of rain to extend through the southern and southeastern Saskatchewan area with local amounts of 100 mm or more.”

Saskatchewan’s Water Security Agency added that rainfall across most of the southern portion of the province is expected to be near 50 mm in most areas. “Rainfall intensities are expected to be highest along the portion of the southern Saskatchewan-Manitoba border overnight and are the area of greatest concern,” the agency said on Monday.

The Manitoba advisory noted that flooding can quickly affect road conditions, recommending that travelers check road conditions and listening to radio or TV weather and flood updates. Travellers should also: not walk through moving water, even as little as six inches (15 cm); not drive into flooded areas; abandon their car and move to higher ground if possible, is floodwaters rise around the vehicle; and not touch electrical equipment if wet or standing in water.

60 mm of rain in some parts of Manitoba last night. Are you waking up to a flooded basement? pic.twitter.com/bFIFk131MB

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