In a Saturday flood bulletin, the province said the system may result in a mix of snow and rain between Tuesday and Friday.
Temperatures are forecast to drop to below freezing by Wednesday and remain below freezing until April 19 in most locations, the province said. Runoff from the forecast precipitation is not expected to start before April 20, according to the bulletin.
“It’s a Colorado Low and it’s tracking in a favourable way to bring southern Manitoba a winter wallop of 30-plus centimetres of wet snow starting Wednesday and continuing through to Friday morning,” said CBC Meteorologist John Sauder.
“It’s a long-lasting event with lots of moisture being fed into the system from the south.”
Sauder said if the system takes a shift to the west, the Red River Valley could get more rain, freezing rain or ice pellets than snow, while western sections of southern Manitoba, including Brandon, would see higher amounts of snow.
“The models are consistent with each run and they are in fairly good agreement, so the confidence in the forecast is fairly high, even though the system is still days away,” Sauder said.
Sauder said winds will be extremely strong Wednesday afternoon and Thursday. Wind gusts could be as high as 70-80 km/h at times, he said.
“This could be the worst April snowstorm since the blizzard of 1997 which contributed to the big flood later that spring,” said Sauder.
The Red River has now reached its peak between Emerson and St. Adolphe, the province said Saturday.
The province said Saturday that a flood warning remains in effect for the Red River from St. Jean Baptiste to Morris and at St. Adolphe. The flood warning is also still in effect in the vicinity of Selkirk due to ice jamming.
A high water advisory remains in place for the Red River from Emerson to the Red River Floodway inlet.
Consistent models runs over the last few days are in general agreement that a major spring snowstorm hits mid week. Starts Wednesday. Could be 30cm or more. Very windy. Mix of precip early in storm. Graphic below is Canadian model at 7am Thurs. <a href=”https://t.co/lTAY4hVOLH”>pic.twitter.com/lTAY4hVOLH</a>
The province began operating the Red River Floodway on Friday morning in an effort to lower high water on the river through Winnipeg.
Elsewhere, the province said water levels are rising on the Assiniboine River from the Shellmouth Dam in western Manitoba to Winnipeg. The Assiniboine is expected to peak between April 11 and April 18, the province says.
The Assiniboine River is expected to remain within its banks at all locations with the gradual snow melt this weekend, the province said.
The province said the Portage Diversion is being operated to limit flows and ice jamming on the lower Assiniboine River, east of Portage la Prairie.