What is the difference in longer days preceded by cooler weather and longer days preceded by warmer weather.This does not seem to make sense.A cooler spring just means a later start for tornado season, no? The greater heating on longer days is the same.
Now, if you put the same kettle on the stove, and heat for 2 hours, the amount of heat the kettle is exposed to is four times as long.
The number of BTU's would vary, depending on factors.
But if the length of the day is 16 hours instead of 13 hours, there are still 3 more hours that the air can be heated by the sun.
There are other factors in the creation of tornadoes: the clash between a cooler air mass and a warmer air mass.
It is my belief that the sun is a heat engine.
I may be wrong.
But one interesting thing was that a tornado hit the same area in 1999 (but it was a much more powerful tornado -- 300 mph winds versus 200 mph winds).
It would be interesting to study when the most powerful tornadoes occur, and plot them by month as the National Weather Service has done for hurricanes.
You Wrote:
...longer days preceded by cooler weather...
Address this first. Note that I may be wrong in what I am suggesting.
I still believe I am right (intuition).
In our current weather, some people have observed fewer clouds this spring. That means the suns heat is not diminished by cloud cover.
If this is the case, then the faucet to turn on energy for tornadoes is greater (the lack of cloud cover means the heat of the sun translates into more heating).
If there is an area near this source of energy that is a clash between cold air/warm air, then there will be more energy.
Longer days translates into more energy ...
Now the other case:
... longer days preceded by warmer weather
Basically, more cloud cover (warmer weather).
With more cloud cover, then there will be less energy available, and the length of the day is less of an issue.