Weren't the thunderstorm warnings somehow too short, constant heat heat heat, then there was a brief spell of heat, but now there's a thunderstorm, what now?

Someone once told me that there are no thunderstorms in the polar regions. In winter, there are sometimes thunderstorms in our latitudes, too. In Greenland, for example, temperatures often fluctuate considerably due to the Gulf Stream. Why shouldn't thunderstorms form there? Does anyone have experience with this?