The Historic 14 April 2018 Upper Midwest Blizzard: Operational Challenges and Decision Support Successes at NWS Twin Cities

Winter storms affect society and commerce on a much larger scale than most other types of weather phenomenon. Significant impacts can be experienced in the Upper Midwest, even at the tail end of a long winter season when people have become accustomed to wintry weather. This storm proved particularly impactful. According to the Minnesota State Climatology office, 20 percent of the state experienced more than 30.5 cm (12 in) and roughly half the state recorded more than 15.2 cm (6 in) – typically the threshold for a Winter Storm Warning. The largest official reports included 67.3 cm (26.5 in) at Canby, 54.4 cm (21.4 in) at Madison, 49.8 cm (19.6 in) at Lake Wilson, and 49.5 cm (19.5 in) at Milan. Several records were broken in the Twin Cities, including largest April snowstorm at 40.1 cm (15.8 in), April monthly record snowfall of 66.3 cm (26.1 in), and the snowiest start to a calendar year with 178.6 cm (70.3 in). The Minnesota State Patrol reported 1,200 vehicles spun out or went off the road, 630 crashes, 70 injuries, 3 serious injuries, and two fatalities. About 750 flights were canceled out of Minneapolis-St. Paul International Airport, which closed all runways for eight hours due to blizzard conditions. Major school districts canceled or delayed classes the following Monday, two days after the heart of the blizzard due to remaining snow-clogged roads. It was also the first time in 27 years the National Weather Service (NWS) posted a Blizzard Warning for Minneapolis and St. Paul, Minnesota. Leading up to the event, NWS Twin Cities conducted numerous webinars, compiled situation reports, e-mail briefings, media interviews, and worked closely with MnDOT in the inaugural year of the newly created “Pathfinder” program. Feedback following the event was entirely positive, despite some operational challenges.