Below Normal Temperatures Continue

Below normal temperatures were observed again this week. Widespread departures of 1-9°F below normal occurred throughout much of the Midwest (Figure 1). In Minnesota, temperatures were 8°F to over 12°F below normal. Itasca County, located in northern Minnesota, observed an average temperature of –1.4°F (12.4°F below normal). Maximum temperatures followed a similar cooler-than-normal trend, except in western Iowa where maximum temperatures were 1-2°F above normal (Figure 2). Maximum temperatures in northern Minnesota ranged from 5-12°F below normal. Minimum temperatures were also below normal throughout most of the Midwest (Figure 3). Less extreme departures (1-8°F below normal) were observed in the east and more extreme (in excess of 8°F below normal) were observed in the west.

Ohio River Valley Receives Above Normal Precipitation

The Ohio River Valley received the majority of the precipitation during the first week of February, where many areas received 1-3 inches (Figure 4). Two waves of moisture from Gulf of Mexico provided a difficult forecast for much of the Ohio River Valley. Rain transitioning to mixed precipitation, then to snow attributed to the above normal precipitation totals from February 1-5 (further analysis below). Most of Iowa, southern Minnesota, and western Wisconsin missed out on any precipitation this week. Everywhere else, 0.1-1 inch of precipitation was widespread. Isolated areas received 1.5 inches. Most of the Ohio River Valley received 125-400 percent of mean precipitation (Figure 5). To the west, most areas received less than 75 percent of mean precipitation.

Difficult Forecast Led to Rain, Freezing Rain, Sleet, and Snow

Winter storm warnings and watches, ice storm warnings, and other winter advisories were widespread from Feb. 1-5. For many, the storm system began as rain. An influx of cold air allowed for precipitation to transition to freezing rain, mixed precipitation, and eventually snow. Freezing rain ice accumulation occurred in Illinois (0.1-0.3 inches), Indiana (0.1-0.35 inches), Kentucky (0.1-0.38 inches), Missouri (0.11-0.25 inches), and Ohio (0.14-0.4 inches). Sleet accumulations occurred in Illinois (0.5-1.8 inches), Indiana (1-3 inches), Kentucky (0.1-2 inches), Missouri (0.5-3 inches), and Ohio (1.3-5 inches). Snowfall totals were highest on an axis from southwestern Missouri through northeast Ohio and southeast Michigan (Figure 6). Many of these areas received snowfall totals in excess of 5-12.5 inches. Isolated locations in northern Indiana received over 15 inches. Many of the areas received 300 percent to more than 750 percent of normal snowfall (Figure 7).