It’s hard not to notice the eerily similar paths taken by the two most destructive and devastating tornadoes in Howard County history.
The Palm Sunday tornado in 1965 and the twister that hit the area in November 2013 both left swaths of destruction in their wake.
Both happened on a Sunday. They both touched down in Clinton County just 5 miles apart. Both moved east and ended up tearing through Kokomo and continuing out into the western part of the county.
So what’s the deal? Is there any reason why the two worst tornadoes had so much in common?
Probably not, said Michael Baldwin, an associate professor at Purdue University’s Department of Earth, Atmospheric and Planetary Sciences who has researched weather prediction methods and forecast verification.
“My short answer is that this is just an unlucky coincidence for Kokomo,” he said.
The longer answer has to do with the tiny amount of historical data meteorologists and other scientists have on tornado activity in the state.
The biggest issue is the nature of tornadoes, which are very rare, generally short-lived and impact a small area, Baldwin said.
Add that to the fact that scientists only have around 60 years of detailed data on tornado activity, and it becomes nearly impossible to draw any definite conclusions to explain why some tornadoes appear to have similar behavior.
“Given the rarity of these events, the length of the high-quality historical record on tornado paths is far too short to have confidence to say that locally observed ‘clusters’ of tornado strikes or paths have any physical or geographical significance,” Baldwin said.
That isn’t to say the physical terrain or geographical features of an area don’t affect where tornadoes hit or the path they end up taking, he said.
“I am saying that we need a much longer historical record to be able to say with confidence that tornadoes are more likely to occur say, in Howard County than in Clinton County, or that tornadoes are more likely to occur downwind of transition zones between rural and urban areas, rather than upwind, for example,” Baldwin said.
In fact, to get any conclusive evidence to determine if geography and terrain cause a tornado to take a specific path, scientists would need around 1,000 years of observation, he said.
That’s because it’s difficult to even track all the tornadoes that hit, since some hit in rural areas or in the dead of night, and no one ever actually observes them.
After a millennium, though, researchers would have enough data to confidently detect local regions of enhanced tornado occurrence, and separate the real activity from the noise.
Baldwin said the general consensus among scientists today is that the exact locations where tornadoes hit are randomly distributed across the state, and there is noa rhyme or reason for why tornadoes hit a certain area.
Tornadoes in Indiana do share one trait, however.
He said the direction in which the storms move, or the tracks and routes they take, typically follow a southwest-to-northeast direction, or a west-to-east direction. There are only rare deviations of this pattern, like storms moving from the northwest to the southeast.
Baldwin said given some of the similarities between the Palm Sunday and 2013 tornadoes, it’s understandable why people might think there’s hard facts to explain why a tornado strikes in a certain area and travels where it does.
And there might be hard facts, he said. But as of now, enough data just doesn’t exist to make a conclusive determination.
“It’s natural for people to think that their local area is more or less prone to tornadoes, and trying to understand the physical reasons that explain why that might be the case is a valid area of research,” Baldwin said.
“However, this is quite difficult research to perform, due to the short-lived, small scale and very rare nature of these phenomena," he said.