Updated at 4:25 p.m. April 18th 2023 - Environment Canada has ended the Winter Storm Watch for the western Red River Valley, including for the communities of Morden, Carman, Winkler, Altona and Emerson, but according to CMOS Accredited Weathercaster Chris Sumner, that doesn't mean the impending arrival of a strong Colorado low won't lead to wintry impacts for the region.
"This is a perfect example of the notorious difficulty there is with forecasting Colorado lows, and falls in line with the guidance provided Monday regarding how additional tweaks could be required as the storm's path became clearer," explained Sumner. "It's important to note, even though these areas are currently not under a weather watch or warning, we can still expect less than ideal conditions later this week as this system moves through the province."
He noted the western Red River Valley remains just on the edge of where stronger impacts are forecast, and with the possibility of this system's track changing further, it's still possible Watches or Warnings may be reissued between now and Friday.
"We're still expecting gusty winds beginning Wednesday, with showers possible," he said. "We're still looking at 5 to 10-ish cms of snow Thursday, with lingering flurries lasting into Friday morning. At this point, the target still remains on Westman for the highest snowfall totals, but the western Red River Valley can still count on flakes falling. Again, though, additional adjustments to the highest impact areas may still happen."
Meanwhile, Snowfall or Winter Storm Warnings are now in effect for all of Western Manitoba and eastern Saskatchewan. 10 to 20 cm of snow, or possibly more, and periods of blowing snow, will begin early Wednesday in those areas.
A low pressure complex developing near the Canada/U.S. border will spread heavy snowfall into southeastern Saskatchewan and southwestern Manitoba. The snow will be heaviest on Wednesday morning, but accumulating snowfall will persist into Thursday for many locations.
Our initial story on this storm can be found below.
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Updated at 6:01 a.m. April 18th, 2023 - We've all heard the jokes and seen the meme's... winter, followed by fake Spring, second winter and then actual Spring. so if that's the case, and second winter was the snowstorm prior to Easter weekend, what does this latest Colorado low equate to?
"My suggestion would be enough is enough," said CMOS Accredited Weathercaster Chris Sumner after Winter Storm Watches were issued for most of Southern Manitoba. "The sunny conditions to start the week certainly lifted our winter weary spirits, and raised hopes of 'real Spring' really being here. It appears those hopes will be dashed in the coming days as a complex set-up, including a potent Colorado low, brings winter conditions back to the forefront."
The Winter Storm Watch extends from the Saskatchewan border to the Red River, as well as into the Parkland region, west of Lake Manitoba. A large swath of southcentral and southeastern Saskatchewan is also under the same Watch.
According to Environment Canada, impacts from the Colorado low are expected to begin in Western Manitoba overnight Tuesday into Wednesday morning, spreading eastward into the Red River Valley and southeastern portions of the province. Total snowfall accumulations of 10 to 25 cm are possible, with the highest amounts expected over higher elevations.
"When you see that snowfall range, there's a couple important things to keep in mind," noted Sumner. "The ground has warmed considerably since the previous snowstorm, meaning a substantial amount of the initial snowfall will melt on contact, or melt shortly afterward. For those regions on the lower end of expected snowfall range, there may end of up being little accumulating snow. For the higher elevations of the Parkland and Westman, it's likely there will be accumulation in areas with higher snowfall rates and accumulations. The other factor is temperature, coupled with where that snow/rain line ends up landing. The regions on the outer edges of this event could see more wet snow and rain, leading to less likelihood of accumulation."
Sumner said, based on the current forecast model guidance, it looks like Westman and the Parkland will see the highest impacts, but that could change depending how the low actually ends up tracking through the region. He noted the current forecasts suggest 10 to 20cms of snow is likely for Westman, and 10+cms for the Red River Valley and Southeastern regions, "but again, a lot of that snow will melt before piling up, so what we actually see on the ground, at least initially, will be less than the snowfall estimates projected. If temperatures remain cooler, and a base layer of snow can establish, then yes, noticeable accumulating snowfall will develop and stay through the event."
Rain mixed with snow will move into the far western side of the province overnight Tuesday, with precipitation transitioning to snow during the overnight hours. The heaviest snowfall will begin early Wednesday morning. Environment Canada is projecting total accumulations of all types of precipitation may exceed 30 mm for some areas.
"With much of Southern Manitoba, especially the Red River Valley and Southeastern regions still seeing meltwater move through the respective local drain systems, this additional precipitation may lead to overland flooding concerns in regions, which to this point, had been seeing, for the most part, a fairly uneventful Spring compared to last year's widespread issues," Sumner added.
In addition to heavy snow, strong northeasterly winds will develop, with gusts of 60 to 80 km/h expected. Wind gusts expected to top out around 60 km/h in the western Red River Valley and Southwestern Manitoba.
At this point, lingering effects from the Colorado low are expected to continue into Friday morning, before the system finally pulls out of the region that afternoon. Those include light snow and breezy conditions.
"I want to stress, there is still uncertainty regarding a number of aspects related to this event, so expect additional adjustments to today's projections and forecast as we get closer to the snowstorm's arrival, " he said.