According to Environment Canada, a significant spring storm is set to impact portions of southern Saskatchewan and southwestern Manitoba on Tuesday night into Wednesday and possibly Thursday this week.
Special Weather Statements have been issued for all of Western Manitoba, as far east as the Pilot Mound and Manitou regions.
A large-scale trough of low pressure, extending northward from a Colorado Low in the northern plains of the United States, will give a prolonged period of precipitation to the southern Prairies. Total snowfall amounts will likely be in the 10 to 20 cm range by the time the system departs late week.
There are several uncertainties and complicating factors that remain to be determined with this system.
Mild temperatures ahead of this system as well as heavy, wet snow will lead to plenty of melting and compaction on contact as it begins to accumulate. Precipitation will likely be mixed at times with rain, especially over south-central Manitoba. Higher resolution model guidance shows the potential for multiple waves of precipitation, which would complicate total accumulation predictions. In general, various model guidance remains muddled, with little in the way of a consensus of areas affected and total precipitation amounts.
Early this morning, there were no special weather statements, watches or warnings for Portage la Prairie but that quickly changed and a special statement was listed by 6:25 a.m.
special weather statement details here
Current thinking is that precipitation will begin overnight Tuesday into Wednesday for most regions, although there may be an area of mixed precipitation ahead of the main area of precipitation on Tuesday afternoon into the evening. Total accumulations of all types of precipitation may exceed 20 mm for some areas, greatly exacerbating the flood situation for some regions. The highest confidence for the heaviest precipitation lies over eastern Saskatchewan and western Manitoba, roughly from Regina to the Manitoba Parklands. The greatest uncertainty lies over western Saskatchewan, west of Regina, and the Red River Valley, east of Portage la Prairie in Manitoba. In addition to the snow, moderate to strong easterly winds gusting as high as 60 km/h will lead to poor travel conditions, particularly on Wednesday.
Snowfall or winter storm watches and warnings will likely be forthcoming for some regions as the event draws nearer, and the evolution of the low-pressure system in the United States becomes more clear.