December 8-14, 2023

Generally Above Average Temperatures Across the Midwest

There was no sign of ol’ man winter during the second week of December, with widespread above-normal temperatures for the region. Average temperatures across the region were 5-15°F above normal (Figure 1). Statewide temperature anomalies were at their lowest in Kentucky, where temperatures averaged 3.8°F above normal. In Minnesota, the average statewide temperature was 12°F above normal for the week. As of December 14, several cities with long term climate data were running toward top 5 warmest Decembers on record, including International Falls, Minnesota and Muskegon, Michigan.

Minimum temperatures were also anomalously warm. Areas of Minnesota and Wisconsin observed minimum temperatures over 10°F above normal for the period (Figure 2). Much of the rest of the region observed minimum temperatures 4-8°F above normal. Youngstown, Ohio, South Bend, Indiana, Chicago, Illinois, and Kirksville, Missouri observed top 5 warmest minimum temperature records on December 8. This continued across much of the region for most of the period. Akron Municipal Airport in Akron, a station with 75 years of recordkeeping, set daily minimum temperature records three days in a row December 10-12.

Maximum temperatures were 6-12°F above normal across the region (Figure 3). Daytime high temperatures averaged in the mid-upper 50s for places like St. Louis, Missouri and Lexington, Kentucky for most of the period. A maximum temperature of 59°F in Des Moines, Iowa on December 8 was 21°F above normal and the second warmest on record. In Indianapolis, Indiana, a temperature of 67°F on December 9 was 23°F above normal and tied for the warmest on record. Temperatures reached the upper 50s and 60s as far north as Michigan, which was 20-25°F average for most of the state. Records were broken on December 9 in Ann Arbor, Battle Creek, Detroit, Lansing, Flint, Saginaw, and Muskegon. A brief cool down back to near normal temperatures ensued mid-week, but by December 14, records were being set again, this time in Minnesota. St. Cloud tied for the record warmest temperature on December 14, with an observation of 53°F, 27°F above normal. On the same day, in International Falls, a temperature of 52°F was the warmest on record, and a whopping 31°F above normal.

December Precipitation Deficits Continue

The second week of December was remarkably dry across the Midwest. Only southeastern Kentucky, parts of Michigan’s Upper Peninsula, and far northwestern Minnesota observed very slight precipitation surpluses of generally less than an inch (Figure 4). In western Kentucky, southern Indiana, southern Illinois, and southern Missouri, precipitation deficits were generally under one inch.

For the second week in a row, parts of Minnesota and Iowa did not receive any rain. Several locations did not record any precipitation as of December 14 (Figure 5). Much of the western Midwest has struggled with drought since the summer, and it continues to expand across the region. Only 20 percent of the Midwest isn’t reporting any drought conditions (Figure 6). Abnormally dry conditions expanded from 75 percent to 79 percent. Expansions were also noted in the moderate (D1) and severe (D2) drought categories, especially over southern Illinois, Missouri and Kentucky. Extreme drought (D3) continued in eastern Iowa.

Snowfall was limited to the Upper Midwest, where even there, it was meager and below normal. At most, northwestern Minnesota and parts of the UP observed 3-6 inches (Figure 7). International Falls, Duluth, and Traverse City, Michigan all observed less than two inches for the week.

December Tornado Outbreak

A sharp cold front was racing east across the country on December 9 (Figure 8). This, combined with anomalous moisture and warmth ahead of the front, provided the necessary ingredients for severe weather across the mid-south. Some of this severe weather hit areas of Kentucky, specifically Todd and Logan counties.

One tornado started just northwest of Clarksville, Tennessee, and caused EF3 damage. Upon entering Todd County, Kentucky the tornado weakened slightly to an EF2. Many homes and structures along the path of the tornado sustained severe damage. As the tornado became an EF1 and moved into Logan County, Kentucky, it maintained winds of 115 mph, and spent over 18 miles on the ground tearing up roofs and scattering corn and bean debris on area roadways. There were no deaths and injuries reported with this tornado.

Despite the aforementioned tornado being the most noteworthy of the day, an EF1 tornado was observed through Warren County, Kentucky, including parts of Bowling Green. This tornado had sustained winds of 90 mph, and caused mainly shingle and rooftop damage. The Super 8 Hotel in southern Bowling Green sustained significant roof damage, as did nearby apartments. Several hours later, another EF1 tornado moved through Monroe County, Kentucky, causing damage to several chicken barns and tearing the porch off a home.

While December tornadoes are uncommon—only 28 happen nationwide on average annually, as opposed to 182 on average for April—several significant tornadoes have occurred in December in Kentucky in recent years. This includes the EF4 that hit Mayfield on December 10, 2021. There were four other EF3 tornadoes that affected the state during that same December 2021 outbreak. The last major December tornado prior to 2021 was an EF3 near Owensboro, Kentucky on December 9, 1952.