Southern Manitoba will see its third clipper-like system of the week, with a very fast moving low-pressure system descending out of Saskatchewan Thursday.
“It’s been active week as we transition out of this long stretch of well above average temperatures to what is looking likely to be at least seven to ten days of very cold conditions for this time of year,” said CMOS Accredited Weathercaster Chris Sumner. “The best way to describe how this Alberta clipper will move through the region would be ‘blast’, because it is moving at a very good clip, and will pack a strong punch for a relatively short period of time starting late tonight.”
Environment Canada issued a Blowing Snow Advisory for the western Red River Valley around 3:40 p.m., including the Morden, Carman, Winkler, Altona, Morris and Brunkild areas. The Advisory was expanded to include the Emerson, Steinbach, Vita and Richer regions just before 6 p.m. According to Environment Canada, blowing snow is expected to develop in those regions late this evening, creating poor visibility near zero at times.
On the back side of the low moving through the province, strong northwesterly winds will develop with gusts between 70 to 80 km/h. The freshly fallen snow from earlier in the day, plus the gusty winds, will create conditions for blowing snow. Blowing snow should diminish Friday morning as the low pushes eastward and winds weaken.
Snowfall began in southwestern Manitoba Thursday afternoon, and will progress eastward throughout the remainder of the day, with the expectation that by late afternoon, or early this evening, flakes will be falling in much of the region.
“We’re not expecting a lot of snow, more than likely similar figures to Tuesday’s clipper, which brought up to 5cms in most locations,” Sumner added. “We could see slightly higher amounts, but not significantly more. The real story over the next twenty-four hours will be the wind, and how severe of a blowing snow event we see.”
Ahead of the system’s arrival, southerly gusts up to 60 km/h will be possible, shifting northwesterly as the low’s cold front passes through.
“On the backside of this low we’ll see winds subside for a bit, and then late tonight and overnight into Friday, they will pick up quickly, gusting between 70 and 80 km/h,” he noted. “The strongest gusts are projected to be within the Red River Valley.”
It’s a pretty easy equation, strong winds plus light fluffy snow will mean blowing snow for a period of time late tonight into Friday morning.
“The potential is there for significantly reduced visibility, especially in the open areas of the Red River Valley,” said Sumner. “That area south of Winnipeg with Brunkild, Winkler, Vita and Steinbach forming the four corners is where I would suggest the highest potential for visibility to potentially approach white out conditions, at times.”
Friday will mark the beginning of a dramatic downward plunge in temperatures, as arctic high pressure builds behind the aforementioned low, allowing a lobe of the Polar Vortex to sneak southward, and settle in for an extended period of time over Western Canada.
“We’re talking seven to ten days of temperatures well below average,” stressed Sumner. “At this point, it’s looking like through the end of January, and the first weekend of February, is the timeline for the really cold conditions. Some of the long range forecast models are suggesting we could see a little moderation to warmer temperatures after February 4th or 5th, but it could be short lived before another round of chilly weather arrives.”
Average daytime highs for this time of year are -11, with overnight lows of -20. From Saturday through early February, highs are expected to range between -19 to -23, with overnight lows nearing or dipping below -30.