Which type of front produces the most violent weather?

Question

Which type of front produces the most violent weather?

Answer 1

Cold fronts are capable of producing more violent weather than warm, occluded or stationary fronts. This is due mostly to the rather sharp slope of the front. Most of the time, what happens is  that warm, moist air would already be in place over a broad area. Then, as the cold front approaches, the cold air will undertake the warmer air and lift the warm air abruptly enough that it cools down quickly. As this happens, any moisture that was within the warm air would condense as it was cooled and produce tall clouds. These tall clouds are known as cumulonimbus clouds, or "thunderheads". Thanks to the sharp lifting motion, thunderstorms would develop given that instability and moisture were available as well.

Answer 2

Cold fronts and cold frontal occlusions.  These fronts generally are more convective in nature,  meaning a lot more thunderstorm, tornadoes and high winds.