A recent storm in southern Manitoba brought unexpected dirty rain instead of the anticipated cleansing showers. The inclement weather, characterized by dark, muddy rain, coated parked vehicles in a layer of grime reminiscent of a dusty road. Environment Canada issued blowing dust and wind advisories for extensive regions in southern Manitoba and Saskatchewan on Thursday. The national weather agency anticipated blowing dust to persist throughout the day until the winds subsided later in the evening. Strong westerly winds with gusts reaching up to 90 kilometers per hour were forecasted to reduce visibility in certain areas and lead to subpar air quality.
University of Manitoba climatologist Alex Crawford explained that dirty rain occurs when winds lift dust particles into the air, where they mix with rain before descending back to the ground. This phenomenon, he shared on CBC Manitoba’s radio show “Up to Speed” with host Chloe Friesen, results in dust residue left behind once the rain evaporates. Despite the necessity of strong winds for dirty rain, Crawford suggested that wind patterns originating from drought-affected regions in the western United States, such as Wyoming and Nebraska, played a significant role in the dusty conditions experienced in Winnipeg. Although dusty air can be problematic for individuals with respiratory issues, Crawford reassured that dirty rain does not pose a substantial health risk beyond the norm.