OK, let's look at which of the 3 states was the most consistent in tornado days. For the 2000-2004 time period, if you use the standard deviation to derive a variance, yields the following:
Seasonal tornado days, for May-June-July combined:
1. Kansas: Avg 13.6, 1 Std Deviation variance = 12%
2. Nebraska: Avg 14.4, 1 Std Deviation variance = 27%
3. Oklahoma: Avg 6.8, 1 Std Deviation variance = 17%
Therefore, you can say Kansas was the most consistent tornado producer from season to season, even though Nebraska had higher total numbers. Statistically, since 2 standard deviations +/- the average gives you about a 95% probability, you can say that you would have a 95% chance of seeing at least 10 tornado days per season in Kansas.
For the most consistent month, June has been closer in consistency to May than one might first assume:
KS-NE-OK combined, tornado days by month:
1. May: Avg 15.4, 1 Std Deviation variance = 21%
2. June: Avg 12.4, 1 Std Deviation variance = 17%
3. July: Avg 7.0, 1 Std Deviation variance = 26%
Therefore, you would have had a 95% chance of seeing at least 9 tornado days in May, but also a 95% chance of seeing at least 8 tornado days in June had you chased the 3-state area over this time period.
Of course, using only 5 years is probably too small of a population, but maybe we can expand the study later.
