I believe that Jay's element isn't Lightning, but Weather. Here's my evidence:
-In Episode 10, when the ninja are in the Fire Temple, fighting the serpentine, Jay shouts "Wind!" while releasing a turrent of wind. Wind has nothing to do with Lightning, but is definitely an aspect of Weather. The episode is here (go to 14:43):-Weather makes more sense as one of the Four Main Elements of Creation used to create Ninjago. Lightning can't be used to create anything, but weather makes up a lot of Ninjago.
-Jay was the first to learn spinjitzu. As the Master of Weather, he would have control over winds (and in that case, tornadoes), so therefore he should be the first to master a fighting style based on tornadoes.
-Jay named his first dragon, Wisp. That name has nothing to do with lightning, but does match a quality of winds and weather.
What do you think?