Variable Temperatures in the Midwest

Average temperature departures across the lower Midwest were near normal to 3°F above normal (Figure 1). Isolated locations in southern and northwestern Missouri, and Kentucky were in excess of 3°F above normal. Central Illinois and northwestern Indiana were slightly below normal. In Minnesota, Wisconsin, and northern Michigan, temperatures ranged from near normal in the south to as much as 15°F below normal in the north. Saint Louis County, located in northeast Minnesota, recorded an average temperature of –6.6°F (15.5°F below normal). Maximum temperatures (Figure 2) were much warmer than normal across most of the Midwest, with the most significant departures in Iowa (ranging from 3-12°F above normal). Colder than normal maximum temperatures were observed in northern Minnesota, northern Wisconsin, and northern Michigan. There were 27 daily high maximum temperature records and 41 daily high minimum temperature records broken or tied. Despite the above normal daytime temperatures, almost the entirety of the Midwest experienced below normal minimum temperatures (Figure 3). The coldest departures occurred in Minnesota, Wisconsin, and northern Michigan.

Ohio River Valley Receives Above Normal Precipitation, Leading to Above Normal Streamflow

Consistent precipitation fell across the Ohio River Valley where totals ranged from 1-2 inches, with isolated totals up to 4 inches in southeastern Missouri, southern Illinois, and western Kentucky (Figure 4). These totals were widespread 0.5-1 inch above normal, with 1-3 inches above normal southeastern Missouri, southern Illinois, and western Kentucky (Figure 5). Combined with melting snow, average streamflows across the Ohio River Valley were much above normal (>90th percentile), with many record high flows measured in southern Illinois, Indiana, and Ohio (Figure 6). Most of northwestern Missouri, Iowa, southern Minnesota, and western Wisconsin received less than 0.3 inches (some no precipitation at all). Isolated locations in northwestern Minnesota recorded 0.2-0.5 inches of precipitation.

Snow Storm Impacts the central Midwest, Additional Snow in the North, Storms in the South

On an axis from central Missouri to southeast Michigan, snowfall totals from the February 16-18 winter storm ranged from 1.5 to 7.5 inches (Figure 7). Most of this region received snowfall that was 1-3 inches above normal with a large swath of 3-5 inches above normal to the west (Figure 8). Lesser amounts were recorded to the south because more mixed precipitation fell in those locations. Poor road conditions resulted in a 100-car pileup on Interstate-39 near El Paso, Illinois on February 17, with multiple other traffic accidents occurring throughout the Midwest. Most of the difficulty was associated with the ice accumulation followed by the snowfall. Snowfall totals ranged from 1 – 7.5 inches in Minnesota, which was 1 – 4 inches above normal. Additional lake effect snow impacted northern Michigan where snowfall totals were more than 7.5 inches. There were eight severe wind reports associated with downed trees on February 17 in Kentucky.