NOAA's National Centers for Environmental Information
Visit:NCEI U.S. Tornadoes
According to data from NOAA's Storm Prediction Center, during December, there were 93 confirmed tornado reports. This is nearly four times the 1991-2010 average of 24 tornadoes for the month of December.
December 13 produced 41 preliminary tornadoes across portions of Texas, Oklahoma, Louisiana and Mississippi. The confirmed tornadoes that have been surveyed by the National Weather Service so far include at least six EF0s, twelve EF1s, ten EF2s and one EF3 tornado. Most notably, an EF2 tornado near Four Forks, Louisiana caused two injuries and two fatalities, an EF2 tornado near New Iberia, Louisiana caused 16 injuries, an EF2 tornado near Norco, Louisiana caused eight injuries and one fatality, and an EF3 tornado near New Iberia, Louisiana caused 16 injuries. The EF3 tornado carved a 9.1 mile path with maximum winds of 140 mph. These tornadoes caused damage to homes, vehicles, businesses, vegetation and other infrastructure. In total, there were more than two dozen injuries and two fatalities.
On December 14-15, 46 tornadoes were reported across eastern Louisiana, central Mississippi, southern Alabama, the western Florida Panhandle and additional scattered tornadoes in central Florida and southern Georgia. These tornadoes were part of a severe weather outbreak that affected the Deep South and Gulf Coast on the 14th and 15th of the month. These tornadoes caused scattered damage to homes, vehicles, businesses and infrastructure. Examples include two EF2 tornadoes that produced significant tree damage in Washington and Choctaw counties in southwest Alabama. Another EF2 tornado caused significant damage to trees, mobile homes, and a cotton gin facility in Colquitt County in southern Georgia. An EF1 tornado caused significant tree and structural damage in Sumter County in southwest Alabama. Some tree and roof damage was reported from an EF1 tornado in Wakulla County just south of Tallahassee, Florida. An EF0 tornado produced mostly minor damage in nearby Franklin County. Two EF1 tornadoes were also confirmed in the Tampa Bay area in Pasco, Hernando, and Pinellas Counties. There were 14 reported injuries and one fatality.
Did You Know?
Tornado Count
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:
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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.