December 15-21, 2024

Temperature

Several warm fronts spread across the region during the week, keeping temperatures warm. Temperatures averaged mostly above normal by 3-6°F across the region (Figure 1). In far northern Minnesota, they were just 1-2°F below normal. Minimum temperatures were anomalously warm, with some areas averaging nearly 10°F above normal for the week (Figure 2). Maximum temperatures were most above normal from I-80 southward and near normal to slightly below normal for the Upper Midwest (Figure 3). In Youngstown, Ohio, the temperature was at or above 55°F for two consecutive days, December 16-17, which is nearly 20°f above normal for that point in December.

Precipitation/Drought

The aforementioned warm fronts were associated with several low-pressure systems, the bulk of which took a southerly track across the region. This resulted in a belt of precipitation that was over 200 percent above normal from southern Missouri eastward along the Ohio River (Figure 4). There were 62 daily precipitation records this week, many of which were in the mid-Mississippi River Valley in Missouri and Illinois (Figure 5). One station in Billings, Missouri received 2.33 inches on December 16, the largest single-daily precipitation event in December since 2015.

While much of the precipitation south of I-80 was in the form of rain, across the Upper Midwest, most precipitation fell as snow. Over six inches of snow fell in a band stretching from central Minnesota to the Wisconsin coastline (Figure 6). As much as 8.9 inches was recorded from this single event in Rice County, Minnesota. The system that pushed through Minnesota and Wisconsin on December 19 closed schools and caused travel impacts in areas like the Twin Cities.

Drought did improve thanks to a more amplified atmospheric pattern. Improvements were made in all categories, with less than 65 percent of the region in abnormally dry (D0) conditions since September 3 (Figure 7).