While Alberta/Montana deal with heavy snow today into tomorrow, winter storm watches and warnings have now been issued for parts of Saskatchewan and may be expended east as the deformation zone becomes more clearly established.
"SUMMARY...Heavy snowfall rates around 1 inch/hour are expected through midday near and along the I-25 corridor from immediately northwest of Great Falls to the east side of Glacier National Park. Radar mosaic shows a moderate to heavy precipitation shield with the southern edge currently in between Helena and Great Falls. Surface temperatures are near freezing (32 degrees F) at Great Falls according to the 8am MDT observation. Colder temperatures are observed farther north (Cut Bank 26 degrees F). The strong orographic forcing (due to the gradual eastern rise to the higher terrain) and large-scale ascent will favor 0.5-1.0 inch per hour snowfall rates through the day. The marginal buoyancy noted in the Great Falls raob suggests locally higher rates (perhaps exceeding 1 inch per hour) are possible for several hours this morning with weak convective elements contributing to an enhancement of snowfall rates." -SPC
4:26 AM CST Saturday 28 September 2019 Winter storm warning in effect for areas in red:
Hazardous winter conditions are expected. An intense low pressure system over the northwestern United States will slowly work its way northeastward and spread snow over southwestern Saskatchewan. The snow will begin in the southwest corner of the province this morning and work its way northeast, reaching Moose Jaw and Regina some time tonight. By the time it gets to Regina, precipitation will be mainly in the form of rain.
The worst conditions will be south of Swift Current and west of Assiniboia overnight and throughout the day on Sunday where snow and blowing snow will give significantly reduced visibilities. The snow will continue pushing northeast towards the Outlook and Humboldt regions Sunday night. A winter storm watch is also in effect for the Leader, Swift Current, and Moose Jaw regions as the worst conditions will arrive there a bit later.
Total snowfalls could reach 30 cm near the Cypress Hills, with amounts gradually lessening as you go north and east. Areas south and east of Regina will have either rain or mixed precipitation, while areas north of Saskatoon will escape the brunt of the system. Please listen for updated watches and warnings as this system moves in over the next day or so. Consider postponing non-essential travel until conditions improve.