According to data from NOAA's Storm Prediction Center, during December, there were 193 confirmed tornado reports. This is approximately eight times the 1991-2010 average of 24 tornadoes for the month of December. This was the highest U.S. count of December tornadoes on record - double the previous final record of 97 from 2002.
December 10 produced a historic December tornado outbreak across several southeast and central states caused devastating damage across many towns and cities. This outbreak produced two long-tracked EF-4 tornadoes across Arkansas, Missouri, Tennessee and Kentucky. The longest tornado track was nearly 166 miles across Kentucky and a small portion of Tennessee. This was the longest-tracked tornado on record in Kentucky and was a U.S. record tornado track length for the month of December. There were over 800 total miles of tornado path length on December 10. The peak intensity from this outbreak was EF-4 rated wind speeds of 190 mph in Mayfield, Kentucky. Mayfield's downtown district was heavily damaged. This day was also the deadliest December tornado outbreak (93 direct and indirect fatalities) recorded in the United States surpassing the Vicksburg, Mississippi tornado of December 5, 1953, which caused 38 fatalities. There were also many more people that sustained injuries from this outbreak of torandoes.
On December 15 there was another record-breaking December tornado outbreak that caused widespread damage and was focused across Kansas, Nebraska, Iowa, Minnesota and Wisconsin. There were many reports of hurricane-force thunderstorm wind gusts and more than 50 tornadoes causing widespread damage to homes, vehicles, businesses and infrastructure. This was the first December derecho on record to occur within the United States. This event also produced the first December tornado on record in Minnesota since 1950, with 20 tornadoes reported across southeast Minnesota.
The year ended with several days of tornadoes across the southeast from December 29-31, as 19 tornadoes were reported across Georgia and Alabama over 3 days. These were all EF-1 or EF-0 torandoes that caused scattered damage to homes businesses, vehicles and infrastructure. Winfield, Alabama was hit by an EF-1 tornado that damaged numerous businesses. Colquitt, Cook and Jeff Davis counties in Georgia were also hit by tornadoes that caused damaged to many homes and vehicles. At least 6 injuries were reported, but no fatalities were associated with this event.
Did You Know?
Final monthly tornado counts are typically less than the preliminary count. This can be due to some phenomena being inaccurately reported as tornadic activity or a single tornado being reported multiple times. Tornado accounts are reported to the local National Weather Service forecast offices who are responsible for going into the field and verifying each tornado reported. This process often takes several months to complete. Once all reports have been investigated, the final count is published by the Storm Prediction Center (SPC).
The Tornado Monthly Climate Reports are written using the preliminary numbers because the final data is not available at the time of production. Historically, for every 100 preliminary tornado reports, at least 65 tornadoes are confirmed. An error bar is depicted on the tornado count graphic representing this uncertainty in the preliminary tornado count.
The following U.S. studies performed by SPC meteorologists offer deeper context and discussion regarding the frequency and distribution of tornado intensity climatologies:
- Edwards, R., H. E. Brooks, and H. Cohn, 2021: Changes in tornado climatology accompanying the Enhanced Fujita scale. J. Appl. Meteor. Climatol., 60, 1465-1482, DOI: 10.1175/JAMC-D-21-0058.1.
- Mccarthy, Daniel & Schaefer, Joseph. (2004). Tornado trends over the past thirty years. paper presented at 14th Conference on Applied Meteorology.