Tornado Season 2010 - Active Or Not For Nebraska

So far, tornado season in Nebraska has been well below average. Up to May 14th, there have been only three tornado reports and on average, we should have seen about 10 tornadoes. By the end of May, we would typically have seen about 16 tornadoes.

Using tornado data from UNL for the period 1950 to 2006 (a great site by the way), I came up with some probabilities for the chances of a below or above average June and season as a whole based on the activity of the first three months of tornado season - March, April and May.

Looking at the numbers on the graphic, if the early part of tornado season, i.e., the first 3 months, is below average tornado-wise for Nebraska, then chances are very good that June and the entire season end up being below average. However, if the early season is average or above, the chances are 50-50 that June will be active, but very good that the season as a whole will be active.

The reason for this may lie in the fact that certain weather patterns tend to become established during a season, and many times early on in a season, so that once a pattern is in place it often continues. Take this year's snow season for example - heavy snow started very early in October, and while every month was not snowy the general trend for the winter was that of above average snowfall. The same can happen in the summer, and a hot June can be a sign that the rest of the summer season will be quite hot. But there are exceptions, and the graphic certainly shows that not all active or inactive early seasons produce the same results.

The good news is that no severe weather is foreseen for the next several days, so our quiet severe season continues for now. Let's hope that it continues indefinitely.

Mike