Updated at 6:35pm Saturday, May 11th - all severe thunderstorm watches west of the Red River have ended. There is a 60% chance of showers or thunderstorms this evening, with strong winds continuing until diminishing overnight.
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An unusually warm May 11th may end with another couple of rare for this time of year weather events; strong to severe thunderstorms and poor air quality due to wildfire smoke.
Environment Canada has issued a Severe Thunderstorm Watch for a good portion of Southern Manitoba from as far west as Boissevain through Killarney to Pilot Mound, Manitou, Morden/Winkler, Altona and all regions east of the Red River to the Ontario border.
"A strong westerly flow throughout Saturday has been pumping a very warm and dry airmass into the region for this tie of year," explained CMOS Accredited Weathercaster Chris Sumner. "A low pressure system located in northern Manitoba is tracking eastward, and the cold front associated with it may trigger scattered thunderstorms Saturday evening. Because this airmass is very dry, there is little chance of widespread severe weather, or significant widespread rainfall, from any storms that develop. Strong wind gusts is the bigger concern with this set-up."
As the cold front passes, winds will shift northerly late tonight, and remain there throughout Mother's Day Sunday, with gusts up to 50 km/h likely. Daytime highs will also be ten degrees cooler than Saturday, topping out around 18 to 20 degrees. Some locations in the Pembina and Red River Valley reached 30 degrees late Saturday afternoon.
Meanwhile the combination of strong northerly winds behind this low, and forest fires burning in the Flin Flon and The Pas areas, is leading to a band of wildfire smoke moving southwards through Manitoba. This band will bring 4 to 8 hours of poor air quality and reduced visibility as the smoke moves through.
Conditions will improve Saturday evening through central Manitoba. The band of smoke will move into southern Manitoba through the evening hours. Conditions in the south will improve Sunday morning.