After 4 weeks of below normal temperatures, a major shift in the upper atmospheric weather pattern will finally signal a return to more typical summerlike weather over southern MB. The weather pattern over the past month has been dominated by a persistent upper trough over Hudson Bay into the Great Lakes that has resulted in a prolonged period of below normal temperatures over the eastern prairies into Ontario. Including today (August 14th), Winnipeg will have gone 27 consecutive days below normal, at a time when the hottest weather of the season often occurs. During this stretch, Winnipeg has hit the 25C mark only twice, with a maximum of only 25.2C. The normal high during this period is 26C.
The below normal streak however will be coming to end starting tomorrow. The persistent upper trough over central Canada will finally be shifting east and replaced by an upper ridge over the Prairies, allowing warmer air from western Canada to finally spread eastward. High temperatures in southern MB will climb from the mid 20s today to the 30C mark by Friday, with 30c+ weather expected over the weekend into next week. Things may start getting a little more unsettled as well Sunday into Monday as a weak impulse passes though southern MB, tapping warm and more humid air and triggering scattered thunderstorms. Above normal temperatures however are expected to persist much of next week, great news for those who weren't quite ready to say goodbye to the summer of 2013 just yet.