50-80+mm: Excessive rainfall on the Prairies with wet, stormy setup

An upper-level trough and abundant, tropical moisture will lead to significant rainfall for parts of the Prairies this weekend, with some areas potentially seeing 80-100+ mm, creating localized flooding concerns.

Expect widespread rain across the Prairies through your holiday weekend as a stagnant, moisture-rich pattern swings across the region.

Rainfall totals of 40-80+mm will affect a large swath of the region by Monday, with areas that see thunderstorm activity possibly exceeding 100 mm of accumulation.

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Stormy, rainy weekend for the Prairies

A hot and humid to start to the long weekend is expected across southeastern Saskatchewan and southern Manitoba. To go with the heat, scattered showers and thunderstorms develop through the day on Saturday.

Tropical moisture Western Canada Saturday

Storm development will be conditional and localized, with many areas staying dry.

Where storms do form, strong winds are the primary threat, but heavy rain will also be possible.

The setup could become more active along the Saskatchewan-Manitoba border Saturday afternoon and evening.

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Prairies thunderstorm energy Saturday evening

The story will shift to widespread, heavy rain on Sunday and Monday.

A low-pressure system along the Montana-North Dakota border will slowly track east toward southern and central Manitoba.

Rain will become more prevalent on Sunday and continue through Labour Day Monday and into Tuesday.

Prairies storm risk map Saturday

Tropical moisture will help the system drop higher rainfall totals.

Significant rainfall is likely, spreading from Alberta across the southern Prairies. We could see totals of 30-50 mm in Calgary and Edmonton, with a swath of 40-80 mm expected through southern portions of Saskatchewan and Manitoba.

Some communities could see as much as 100 mm of rain as beneath embedded thunderstorms, though there’s still some uncertainty where the heaviest rains will fall.

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Prairies rainfall through Monday

This kind of rain is beneficial for areas that ran dry in July, but it will also have a major impact on fall harvest efforts. Additionally, areas downstream from the heavy rain in Alberta should be on the lookout for rising water levels.

Stay with The Weather Network for all the latest on conditions across the Prairies.

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