Issued: 10 January 2011
According to the Storm Prediction Center (SPC), the final tornado count for the U.S. during 2010 was 1,282. The final 2010 count ranks as the seventh most acive year since records began in 1950. During 2010, seven months experienced above to much–above normal tornado counts — January, April, May, June, July, October, and November.
During 2010, tornadoes were reported in all but four states in the Lower 48 — Delaware, Massachusetts, Rhode Island, and Nevada. Tornadic activity during the year tended to occur in clusters, with the most active regions including the Front Range of the Rockies, the Southeast, the Central and Northern Plains, and the Great Lakes.
Two states in particular had very active tornado years. Arizona had 17 preliminary tornado reports during 2010, tying the state’s annual record, which was set in 1972. The second most tornadoes occurred in 1992 with 13 reports. Eight of the tornadoes occurred on October 6th, marking the most tornadoes to strike in Arizona during a calendar day since records began in 1950. Arizona on average receives four tornadoes annually. The other state with above–normal tornado activity was Minnesota. The state experienced 113 tornadoes during 2010, the most of any state in the country this year, and the most the state has experienced on record. The 2010 tornado count surpassed the previous record which was 74 set in 2001. The annual tornado average for the state is 25. The most active day for the state was June 17th, when 48 tornadoes were confirmed. This bested Minnesota's previous one day tornado count set on June 16, 1992 when 27 tornadoes were confirmed. Minnesota was also the national tornado leader, for the first time on record.
During 2010, there were 44 fatalities directly related to tornadoes across the U.S. during 2010. The count is higher than the 22 reported during 2009, which also had fewer tornadoes. The 2000-2009 average for annual tornado–related fatalities is 62. The deadliest tornado of the year occurred on April 24th, when 10 people were killed in Mississippi. More information on this tornado can be found in the April State of the Climate tornado report.
On June 17th, there were at least 74 confirmed tornadoes reported across the Upper Midwest and Northern Plains, marking the most active tornado day of 2010. This ranks the event as the 17th most active day on record for the U.S., and the largest event since May 23rd, 2008. The time of year for the outbreak was also unusual. This event was the second highest number of tornadoes during a single event during meteorological summer (June–August) on record, behind June 24, 2003. Forty–eight of those tornadoes occurred in Minnesota, helping the state break its annual tornado record. Tornadoes were also reported in North Dakota, Iowa, and Wisconsin. There were four EF–4 tornadoes for this event, which is unusual for the region. According to information from the National Weater Service offices in Grand Forks, North Dakota and the Twin Cities, Minnesota the previous EF–4 or stronger tornado in Minnesota occurred on July 25th, 2000, and the outbreak marked the most EF–4s or stronger in any single event in Minnesota since April 1967. For the entire nation, this was the first time that an outbreak produced four EF–4s since the “Super Tuesday” outbreak of February 2008. There were three deaths reported across the region during the outbreak. This outbreak was associated with one of the most active tornado days in the U.S. during the past 10 years, and was the worst tornado outbreak to occur across the Northern Plains and western Great Lakes in decades.
A storm system moving through the center of the country brought a severe weather outbreak to the middle and lower Mississippi River Valley on December 31st. Fifty-three tornadoes were preliminarily reported across Arkansas, Missouri, Illinois, Louisiana, and Mississippi, marking the 5th most active tornado day during 2010. Four fatalities were reported in Arkansas, and four were reported in Missouri. A tornado outbreak this large during the month of December is uncommon — the 1980-2009 December monthly average tornado count is 23. The current record for the number of confirmed tornadoes during a single day during December is 34, which occurred on December 18th, 2002. Once the tornado count is confirmed, it is likely that this outbreak will rank as the largest single-day December outbreak on record. There were three EF-3 tornadoes confirmed with the outbreak — one near Macon, Mississippi; one near Sunset Hills, Missouri; and one near Cincinnati, Arkansas. An EF-1 tornado hit near downtown St. Louis, but no significant injuries were reported there.