Winter Weather — Union, South Dakota

2020-03-19 to 2020-03-20 · Union, South Dakota

Event narrative

Rain changed quickly to snowfall late afternoon on March 19, with visibility to around one-half mile at times between 1700-2100CST. The intense snowfall rate made travel hazardous during the late afternoon and early evening as winds increased to a peak of 47 mph 3 miles south of Beresford. Snowfall totaled 2.0 inches 6 miles north northeast of Elk Point. Around 0735CST on March 20, a northbound bus attempted to change lanes on snow-covered Interstate 29 5 miles south of Elk Point, lost control, and overturned in the east ditch. 11 passengers were (indirectly) injured.

Wider weather episode

Low pressure intensified moving from southeast Colorado on the morning of March 19, into the Great Lakes early on March 20. A strong band of mid-level frontogenesis progressed slowly eastward across the area during the afternoon and evening hours. The system was initially quite warm, resulting in a swath of moderate to heavy rainfall from northeast Nebraska into northwest Iowa. As the system strengthened on the 19th, much colder air was dragged into the frontal band, and precipitation turned quickly from rain to snow from northwest to southeast, and was accompanied by winds gusting 40 to 55 mph. Snowfall was generally from 1 to 5 inches near and south of Interstate 90, with heaviest bands near the Missouri River and again from the Sioux Falls area eastward along Interstate 90.

Source: NOAA Storm Events Database, event_id 877098. Narrative written by the NWS forecast office that issued the report.