After having one of the best Summers in recent memory with a significant number of days above 25, lots of sunshine and in many parts of the Pembina and Red River Valleys ample and timely rains... a dramatic shift to Fall will happen Sunday.

"The long range forecast models have been predicting this since the start of the week," explained CMOS Accredited Weathercaster Chris Sumner. "An upper level trough will develop in the Jet Stream, that's when it dives well south of Southern Manitoba, that will allow for a very cold for this time of year air-mass to slide southward from northern Canada, and entrench itself in our region for the coming days."


Environment Canada has issued a Special Weather Statement for all of Southern Manitoba, with northwesterly wind gusts up to 90 km/h expected Sunday afternoon. The strongest winds are expected to be from the Saskatchewan border to the Red River.

"An Alberta Clipper will literally blow across the Prairies Sunday, and that could bring a shower or two to the region, and will also bring with it the start of those windy conditions," said Sumner. "As the low passes Sunday afternoon, those winds will strengthen in the afternoon, and continue into the evening."


In behind the Low, an unseasonably cold air-mass will move in, and will drop temperatures more than 10 degrees compared to what's expected Saturday. Highs Saturday will reach 25 to 27, with Sunday being slightly cooler, around 21 to 23, before the Low passes, and temperatures begin to drop. Average daytime highs for September Long Weekend are around 20 to 22, and by Labour Day Monday highs will struggle to reach 10 to 13.

"The other part of the story is the arrival of this air-mass will also bring with it a widespread risk of frost across the region both Monday and Tuesday night," added Sumner. "Southwestern Manitoba may see two consecutive nights of frost risk, with areas further east, including the Red River Valley and Southeastern corner of the province, looking at Tuesday night only currently. Overnight lows are expected to be in the zero-ish range, so we're not talking a hard, killing frost, but definitely enough to more than touch flowers and vegetable gardens."

When asked how long the well below average temperatures will last, Sumner smiled, and said it's looking like not as long as originally expected.

"Right now the models are suggesting by Thursday next week we should be back to average for this time of year, with the possibility of above average temperatures for the weekend of September 11th to 13th."