Parts of Western Manitoba had the first taste of winter Saturday, with 5-15cms of wet snow falling across parts of the region as a low pressure system pushing northward out of North Dakota brought the white blanket.
“Further east, in the Red River Valley and Southeastern Manitoba, those areas remained on the warm side of that system, and only saw drizzle and light shower activity throughout the day,” explained CMOS Accredited Weathercaster Chris Sumner. “This next combination of systems looks much more likely to bring significant precipitation, both rain and snow, to a larger swath of Southern Manitoba.”
That first go around may pale in comparison with what's to come, with Environment Canada issuing a Winter Storm Watch for all of Western Manitoba Sunday afternoon, as far east as the Pilot Mound and Manitou areas, pointing to the Monday night through Wednesday timeframe.
"Precipitation in many areas will start out as rain or freezing rain, then transition to snow as colder air gets wrapped into the system," stated the Watch issued Sunday afternoon. "Very strong northwest winds are expected to develop as the system intensifies, with gusts to 80 km/h resulting in very poor visibility in snow and blowing snow. Blizzard conditions are possible in some areas. Widespread snowfall accumulations of 15 to 30 cm are likely with this system... possibly more over the higher terrain of western Manitoba and eastern Saskatchewan."
According to Sumner, it begins with the arrival of a moisture packed Texas low that will be pushing northward through the central United States throughout Monday, arriving on our doorstep Monday night and then stalling for potentially up to 48 hours.
Get the latest forecast details here
“This low is expected to be reinforced with an atmospheric disturbance that originated from the Pacific west coast that simultaneously is crossing the Southern Prairies,” he said. “The two combined are forecast to create a potent low-pressure storm system that will bring extended impacts from Monday night through at least Wednesday afternoon.”
The precipitation will begin by the early morning hours of Tuesday, with rainfall expected from the Manitoba escarpment eastward to the Ontario border. Snowfall is expected west of the escarpment into Southeastern Saskatchewan.
“There will be a very defined snow/rain line on Tuesday, with areas west of it in the cooler, northerly flow seeing snow, and regions east of the line remaining on the warm side seeing rain,” he noted. “Where that snow/rain line sets up could still fluctuate, so it’s still possible we could see a shift in which areas are on what side.”
The forecast models are still pinning down possible accumulations, but areas that see snow Tuesday could be in line for 10 to 20cms, with possibly higher localized totals, whereas the rainfall regions are in a target range of 15 to 30mm potentially.
“But it’s important to note, those initial estimates will be fined tuned over the next twenty-four hours as we get closer to the arrival of these systems,” Sumner stressed.
Gusty northerly and northwesterly winds are also in the forecast Tuesday, between 40 and 50km/h for much of the day, with the strongest gusts slated for southwestern Manitoba, with peak gusts Tuesday night possibly reaching 70 km/h or higher.
Get the latest road report and cancellation information here
“And those strong winds will coincide with the moderate to heavy snowfall expected in Westman, meaning visibility and general driving conditions could be significantly impacted,” he said.
As the system slowly pushes out of our region, temperatures will drop in the Red River Valley and Southeastern Manitoba, so that by Wednesday morning the rain will have changed to snow in those regions too.
“How much snow will be received is still up in the air, because it will depend on when temperatures get cold enough for the rain to change to snow,” Sumner explained. “If it takes longer, there will be less snow, but if it happens sooner in the duration of this event, there will be more snow. We do need to keep in mind, the ground is still quite warm for this time of year, and some of the initial snowfall will melt before a base is established, and it starts to accumulate.”
Windy conditions are expected to continue Wednesday, with northerly and northwesterly gusts again in the 40 to 60 km/h range across all of Southern Manitoba.
“Impacts from this storm will start to taper off Wednesday night, and by Thursday morning we’re expecting everything to have wrapped up, with just the sloppy, snowy and wet aftermath to deal with.”
Sumner’s bottom line is for anyone expecting to travel in Southwestern Manitoba Tuesday or Wednesday to be prepared for full-on winter driving conditions with reduced visibility due to blowing snow and snow covered roads. Further east, in the Red River Valley and Southeastern Manitoba, the impacts from snowfall, at this point, are expected to be somewhat less, but residents should be ready to adjust to winter conditions quickly after having a very long stretch of well above average weather.
“The way things are looking, this will be a harsh snap back to reality for much of the region, after weeks of consistently warmer than average weather and not a sign of snow until that first taste in western regions on Saturday,” concluded Sumner.