A potent low-pressure system situated over Saskatchewan is significantly impacting the Prairie weather forecast for the May long weekend. Areas east of the Rockies can expect intense periods of rain, damaging wind, mixed precipitation, snow and unusually cold temperatures over the next few days. Yellow-level wind warnings have been issued for the eastern portion of central and southern Alberta. Orange-level wind warnings have been issued in central and southern Saskatchewan, with yellow-level freezing rain warnings and yellow-level winter storm warnings in the northern Prairies and the Northwest Territories. Environment and Climate Change Canada (ECCC) explained, “Winds gusting over 90 km/h have been recorded over much of central and eastern Alberta and will continue through the afternoon. In the Edmonton region, winds gusting near 90 km/h are still possible this afternoon.” Rainfall amounts of 25 to 30 millimetres are likely in areas north of the Yellowhead in Alberta, with ECCC warning accumulations up to 50 millimetres are possible in localized areas, and “Some communities near the Saskatchewan border may see rain transition to snow on Friday.” Cold air wrapping around the western side of that low will suppress temperatures across Alberta over the weekend, with Calgary’s daytime high on Saturday expected to peak at 6 C with a low of 0 C. Areas outside of the city and in low-lying and/or high elevations and/or communities near water will likely see overnight values dip below freezing. Most of the City of Calgary should be slightly warmer due to the urban heat island effect. Mixed precipitation has already been observed in some higher elevations in the Rockies, with areas like Calgary and central and southern Alberta likely to see rain transition to snow on Saturday. Saturday will likely be the wettest day of the weekend in Calgary, with between 10 and 15 millimetres of precipitation.
