Warm Temperatures Continue - Except in the Northwest

While not as drastic as last week, most of the Midwest continued to see above-normal temperatures during the third week of February (Figure 1). Areas in Ohio saw temperatures up to 12°F above normal and had a statewide average temperature of 32.8°F, which is 8.7°F above normal. On the other hand, much of Minnesota and Iowa saw cooler temperatures this week. Northwest Minnesota recorded temperatures up to 9°F below normal, while the statewide average temperature was 5°F below normal. Maximum temperatures followed a similar pattern and reached up to 15°F above normal in Ohio, but slightly below-normal maximum temperatures extended into northern Wisconsin and the Upper Peninsula of Michigan (Figure 2). Minimum temperatures followed this pattern as well (Figure 3). Overall, 82 high maximum and 77 high minimum temperature records were broken or tied this week (Figure 4).

Wet Week for Northwest and Southeast

A lingering upper-level trough was set up over the central United States for the first half of this week, causing two low pressure storm systems to affect the Midwest. On the morning of February 15th, a strong surface low was present in the far northern Midwest with an associated stationary front extending through Illinois and Missouri (Figure 5a, 7am EST). The presence of this front caused Missouri residents to see some severe weather early in the morning, including hail up to 1.25 inches in diameter and wind gusts up to 60 mph. As the day progressed, this low shifted out of the area (Figure 5b, 7pm EST) while another, weaker system set up in the southern Midwest on the morning of February 16th (Figure 6a, 7am EST) and moved northeast throughout the day (Figure 6b, 7pm EST). Warm, moist, and unstable conditions ahead of the cold front led Dixie Alley to see severe weather, including some tornadoes, while southern Kentucky reported areas with high winds. The rest of the southeastern Midwest just received rain with this system, while a swath of heavier snowfall behind the cold front extended from Iowa through Michigan. The subsequent radar images show the system’s placement in the morning (Figure 6c, 7am EST) and the evening (Figure 6d, 7pm EST); areas of higher reflectivity (reds, oranges, and yellows) indicate higher rainfall rates and a higher severe weather potential, while the banded areas of lower reflectivity (blues and greens) indicate snowfall.

Looking at this week as a whole, most of the Midwest received at least 50 percent of normal precipitation, but portions of the northwest and southeast saw upwards of 750 percent of normal precipitation (Figure 7). Kentucky received the most precipitation by far, as the entire state saw at least 1.5 inches of precipitation (Figure 8). Perry County, Kentucky, recorded the highest weekly precipitation total of 5.16 inches. Overall, 162 precipitation records were broken or tied this week (Figure 9). Only the northern Midwest received snow this week, with the previously mentioned swath having dumped up to 500 percent of normal snowfall totals (Figure 10). While other light snowfall was seen throughout the week, most significant snowfall resulted from the two low pressure systems in the beginning of the week (Figure 11). 57 daily snowfall records were broken or tied this week, all within this swath (Figure 12).

Streamflow and Drought Monitor Updates

With the heavy precipitation in Kentucky this week, streamflow conditions shifted from below normal to above normal when compared with last week (Figure 13). Below-normal streamflows were observed in central Ohio and eastern Indiana. Drought conditions improved in the west this week as western Iowa Extreme Drought (D3) was largely downgraded to Severe Drought (D2) (Figure 14). A small area of western Iowa remained in D3 and Exceptional Drought (D4). Areas of Moderate Drought (D1) improved in central Iowa as well.