Saturday, March 30, 2013
Gilbert, Iowa tornado caught by Jim Bishop on November 12, 2005 during the largest November tornado outbreak in Iowa history.
Even during slow tornado seasons there is usually one or two big tornado outbreaks, at least at some point. I mean, you can look at tornado statistics all day long. But when large scale weather patterns change in the spring, it typically involves bringing together a lot of low level moisture with cold air aloft and in turn, strong wind shear. In the end large severe weather outbreaks tend to unfold at least once or twice throughout the spring or summer, regardless of how terrible the pattern or atmospheric conditions have been, or even how the overall season turns out. Remember, mother nature does not care what the calendar says or how many tornadoes have occurred in a year. Things just happen when the conditions come together.
Speaking of tornado outbreaks during slow tornado seasons, one very interesting case comes to mind. The April 10-11 tornado outbreak that spawned tornadoes from north Texas, through Oklahoma and Kansas, all the way up to Iowa. All told, 79 tornadoes occurred during this two day event (See image below).
But what really grabbed my attention was the number of tornadoes in the state of Iowa alone – 28! And all of them occurred on April 11, making it the largest one day tornado event in the state of Iowa. This broke the old record for most tornadoes in one day in the state of Iowa set during the Mother’s Day Outbreak on May 8, 1988. And is it just an odd coincidence that 1988 was also a slow year for tornadoes?
(As a side note, there were only 15 confirmed tornadoes in Iowa on November 12, 2005, the day I witnessed the Gilbert, Iowa tornado – see image at the top. I believe that day stands as the most number of tornadoes in one day in Iowa during the month of November. And as yet another side note, 2005 wasn’t a very active spring for tornadoes.)
April 10-11, 2001 Tornado Outbreak with tornado paths shown in red.
Surface map April 11, 2001 (NCDC) courtesy Iowawx.com
So it’s just kind of interesting that during a slow tornado season a huge outbreak occurs and breaks a single day tornado record for the state of Iowa. It just proves that sometimes big outbreaks happen, and it doesn’t necessarily mean anything at all for the remainder of the season. It’s simply an outbreak that occurred, nothing more.
And another thing, 1988 was a major drought year for a large portion of the U.S., including the Great Plains. This isn’t even something I was necessarily looking for, but in finding this April outbreak in 2001 I saw the statistics for the 1988 Mother’s Day Outbreak in Iowa. In my previous post I mentioned how widespread and severe the current drought is over the central U.S., namely the Great Plains. So again, quite the interesting find. Coincidence?
I think the point in all of this, if there’s a point in all my rambling, is that sometimes you just have to be out chasing on the one or two big tornado days of the season. If you’re not, then you will probably miss out of photogenic tornadoes. This isn’t always true. I’ve seen plenty of low risk setups produce beautiful tornadoes. But sometimes during a slow tornado season you just have to be out there on the big days or wait ’till the fall or the next spring.
Until next time…