Tornadoes also develop occasionally in southern Canada during the Northern Hemisphere's summer and somewhat regularly at other times of the year across Europe, Asia, Argentina, Brazil and Australia.

The fall severe weather season began unusually early, with a moderate event in mid-September followed by a significant outbreak in the latter part of the month.

On January 2, the Storm Prediction Center forecast a moderate risk of severe thunderstorms for much of the southeastern United States from the Ohio Valley to the Gulf Coast.

The second major tornado outbreak of 2006 took place on April 2 in a large swath from Iowa to Mississippi and from western Missouri to the central Ohio Valley.

The Storm Prediction Center had issued a rare high risk for severe weather for both April 6 and 7, with an unprecedented 60% probability of a tornado within 25 miles of a point south of the Nashville area.

Two main clusters - one over Texas and Oklahoma, and the other primarily in South Dakota - produced a total of 10 reported tornadoes, along with powerful straight-line winds of up to 86 mph (139 km/h) and hail up to softball-sized.

As the tornado struck Childress High School, the gymnasium lost its roof and sustained total collapse of a large brick wall.

At Fair Park, a tennis court was destroyed, several metal light poles were bent and snapped, and a pedestrian bridge that spanned a small lake was ripped from its wooden supports and thrown.

While the bulk of the damage was due to large hail, there were at least 17 tornadoes reported (of which seven were confirmed), with the most severe one taking place near Concord, North Carolina.

A hot and humid air mass entered the northeastern part of the U.S as well as much of southern Ontario and Quebec, and severe thunderstorms and tornadoes were sparked by a cold front.

A separate system had reportedly spawned a tornado which inflicted damage to numerous houses near Seymour, Indiana north of Louisville, Kentucky, but it was confirmed to have been a microburst.

[37] Meanwhile, in Pembroke, Ontario further to the east, what was possibly a tornado but confirmed as a microburst, several roofs including one from a marina and another one from a large warehouse were blown away during the passage of a supercell storm.

Numerous funnel clouds were also spotted in Alberta with a separate family of thunderstorms over the Canadian Prairies which also brought tornadoes in the Dakotas the following two days.

A similar pattern to the previous event shaped up over parts of the Upper Midwest, although the risk of tornadoes was initially declared even greater.

A cluster of storms did develop in the late afternoon and early evening hours in Missouri and Illinois with additional activity in Wisconsin and southern Minnesota.

A small outbreak occurred in western Minnesota, and six tornadoes were reported, including a large one near Dawson in Lac qui Parle County near the South Dakota border.

[57] Two people were killed by events unrelated to the tornado but associated by the thunderstorms related to the derecho that crossed southern Quebec for the Upper Laurentians to the coast of Maine.

[61] Initially rated an F1, but upgraded to an F2, the strongest of the evening tornadoes touched down south of Barry's Bay, in the town of Combermere at 8:30 p.m. EDT.

The Minden Hills tornado also destroyed a 500m-long suspension bridge that passes through a nature reserve of original growth white pine forest, often used during guided school tours.

[65] Overall, over 150,000 customers were without power during August 2's storms, mostly in the Georgian Bay, Haliburton, Hastings and Toronto regions, as well as areas near Arnprior, Peterborough, Belleville, Tweed and Napanee in eastern Ontario.

Severe weather erupted in northern Minnesota, southern Manitoba and northwestern Ontario as a strong low pressure system hit the area on August 5.

The morning cells were mostly large hail producers, but in the afternoon tornadic thunderstorms formed and hit several towns in southern Minnesota.

The worst tornado, confirmed as an F2, touched down in Surprise, Nebraska, where at least one mobile home was destroyed and roofs were torn off several businesses.

[83] On September 16, the Storm Prediction Center issues a moderate risk of severe over parts of the northern and central plains, with a large swath from the Canada–US border to Oklahoma having tornado potential.

[98][99] According to Accuweather there were three deaths reported in the severe weather outbreak (but not by tornadoes); two of them when their vehicle was submerged by flood waters while a third was killed in a rollover into a ditch.

A major severe weather event was expected over the U.S. Gulf Coast eastward into the Carolinas, especially beginning overnight on November 15, which was one year exactly after another significant outbreak farther north in 2005.

[113] Another major F2 tornado took place at the east end of Montgomery, Alabama, where the Fun Zone Skate Center was destroyed with over 30 children inside.

All of these storms occurred ahead of the Arctic cold front that was causing severe winter weather from the southern Great Plains into the mid-Mississippi River valley.

A surprise early December tornado lasting for less than a minute and high winds caused significant damage to portions of the suburb of Kensal Rise in North West London, United Kingdom.

[120] After a lengthy period of inactivity, a moderate tornado event took place on Christmas Day in the southeastern United States, primarily in Florida.