Number of United States tornadoes in 2012 near record lows

CLEVELAND - It's been a very quiet summer and fall for tornado chasers everywhere across the United States.

Tornado touchdowns here have hit rock bottom over the past seven months. With just six weeks left in the year, the National Weather Service has counted a paltry 882 touchdowns in 2012.

Now, that may sound like a lot, but, if this trend keeps up, 2012 may end with the fewest tornadoes in the modern era. Tornado records date back to 1950. An average tornado year would see 1,000 to 1,200 confirmed twisters.

“(W)e are approaching a theoretical minimum in the annual tornado count for the modern era,” said Greg Carbin, warning coordination meteorologist at the National Weather Service Storm Prediction Center in Norman, Okla.

2011 was a monster tornado year. The 1,692 recorded touchdowns were second most since 1950. These included devastating storms such as the Joplin, Mo. and the Tuscaloosa, Ala. twisters.

2012 looked like a banner year as well. March and April tornado numbers were some of the highest on record. But, then it all stopped.

“(The) decrease in tornado activity coincided with the development of an extensive ridge of warm high pressure in the atmosphere across the western and central United States,” Carbin said.

“This high pressure area produced both record warm temperatures and extreme drought over much of the middle part of the continent into the summer and autumn," Carbin said.

"The high pressure also acted as a block in the middle and upper atmosphere with more transient but dynamic weather systems, that can lead to tornado development, being shunted northward into Canada.”

“Even when the high pressure weakened enough to allow for some of the more dynamic weather systems to move across the lower 48 states, shear in the atmosphere remained too limited to support more than isolated to occasional tornado events. These conditions didn’t result in a complete lack of severe weather as evidenced by the June 29 Derecho Event, it’s just that conditions supporting more widespread tornadoes were clearly suppressed by the large scale pattern.”

So, where did all the U.S. tornadoes go? They went father north into Canada, which experienced record amounts this past summer. Saskatchewan saw 30 tornadoes in June, July and August. They normally see about a dozen tornadoes per year.