Storm Update: Rain Starting to Fall, Rivers Filling

The South Saskatchewan River at Medicine Hat Friday afternoon. River streamflows are anticipated to peak in the Hat on Wednesday following widespread precipitation across southern Alberta starting today. (Photo Alex McCuaig)

The drenching rain forecast for southern Alberta is starting to fall across the region, but Alberta Environment forecasters are rolling back some of the accumulation amounts.

The latest modeling from Friday morning is anticipating 50 to 100mm to fall across much of the province into the weekend with localized areas possibly receiving up to 130mm.

And the largest accumulations of precipitation are anticipated to be in the areas in most need of rain, namely, the Bow, Oldman and Red Deer river basins, all of which have experienced record low streamflows for June.

Record low streamflows on the South Saskatchewan River basin have also been recorded this month.

A Flood Watch issued for Lee Creek has been downgraded to a high streamflow advisory.

The Bow, Oldman, Red Deer and South Saskatchewan river basins are all under a general high streamflow advisory.

The cities of Calgary and Lethbridge are advising residents to prepare for the storm by staying away from riverbanks due to instability. Both municipalities are also reminding residents to make sure eavestroughs are at least five feet from homes to prevent basement flooding and that they are clear of debris. Both cities are also asking residents to check nearby storm drains for blockages and to report issues to officials.

The City of Medicine Hat is not anticipating any major effects of the forecast heavy rain nor have issued any similar advice to residents.

However, in its June 19 media release, Medicine Hat states the city is prepared to mobilize if things change.

As of early Friday evening, river levels in Calgary, Lethbridge and Medicine Hat have begun to rise with the possibility that could be as high as two metres in some areas. Overland ponding is a possibility in low lying areas.

Peak flows are anticipated to occur late Saturday and into Monday morning except for the South Saskatchewan River which is expected to crest around Wednesday.

Water levels on the Oldman River at Lethbridge have gone up by one metre since the beginning of Friday to the early evening. (Graphic courtesy of Alberta Environment)