It may not seem like it around here with the two different VERY big severe weather days we had in the metro area in June and the largest power outage in state history, but the overall amount of severe weather across much of the country and even our area is historically low. Many locations across the country have been experiencing this tranquil pattern after a monstrous couple of years nationwide with HUGE tornado out breaks in 2010 and 2011 followed by major multi state wind events in both 2011 and 2012. This year has been unusually quiet and that's mostly due to the cool like summer weather in much of the eastern half of the country with cool (cool for summer) air drifting in from Canada during much of the June, July, and August timeframe. Because of this, the National Weather Service hasn't had to issue nearly as many warnings across a large swath of the country, check it out…
There have been a few areas that have dealt with above average amount of warnings, mostly the southwest because of the sheer amount of flash flood warnings that have been issued. But overall, everyone else has been far lower than average. Right here in the Upper Midwest, with the exception of the La Crosse forecast office, everyone has been below average. The only reason for La Crosse's spike was due to flash flooding in May and June. The Chanhassen office that issues warnings for the greater metro is sitting at 57 percent of average… phenomenally low!
As you can imagine, tornado numbers are down as well. The map below shows the official tornado reports from state to state through June. Why only through June? Well, the National Weather Service has preliminary numbers and then official numbers. A preliminary tornado report is what we get when someone sees a tornado and a tornado warning is issued. Until the NWS goes out to the location to verify it was a tornado and then ultimately figure out how strong it was on the EF scale, then it is not considered official. Therefore, official numbers typically lag behind by a couple months.
Minnesota has only seen 5 tornadoes through the month of June. All in all, not largely unusually considering our big tornado months are July and August. But we all know that there was very little severe weather in July, August, and the first half of September as well with just 5 preliminary reports of tornadoes across the state in that timeframe. More often than not, roughly half to two thirds of all tornado reports are confirmed. So if we use that statistic, then there have been roughly 7 tornadoes statewide so far this year… down significantly from the 10 year average of over 50.
Even preliminary tornado reports are low. Below is a graph showing preliminary tornado reports through the middle of September this year as compared to the average. So far, a little over 700 tornado reports nationwide. Our average is over 1300 reports!