2010 Severe Weather Stats Catching Up

NOTE: My Comparing 2010 Hurricane Forecasts blog has been updated with new numbers!

In mid-April I did a blog entry talking about how low the 2010 U.S. severe weather season statistics were compared to previous seasons (we were at a record low for the last 10 years). After I did that blog entry (the timing was not coincidental), the spigot opened up on hail, wind and tornadoes. May 2010 actually had more tornadoes than 2009 and total reports were similar. The graphs below have been updated to reflect SPC spotter reports through May 31st:

As you can see, 2010 is catching up but still pales in comparison to the previous two years. However, that's not the entire story. The big change is when you look at the last 11 years of severe weather reports -- 2010 has switched positions from #11 (slowest) to be the 3rd highest! The number of tornadoes finally surpassed 2005's slow season but is still nothing like the last six years:

I created a modified version of the SPC map showing severe weather reports through May 26th (I put the tornadoes back on top so they wouldn't be hidden by the wind and hail reports):

This is much more along the lines of what I would expect to see by this time of a normal severe weather season and isn't obviously blank like the one I showed back in April. The map below removes the wind and hail reports and splits up the tornadoes by month. As you can see, Tornado Alley really lived up to its name during (late) April and May. Although it's too soon to call our Seasonal Tornado Forecast (which runs through the end of June) it would seem that the unusual tornadoes east of the Mississippi were an addition to Tornado Alley action, rather than a "shift."