Bomb cyclones are intense storms, often hybrid storms. Graphic explains center-jumping storms . Graphic shows conditions favoring development of MCCs Complex fronts, gravity waves Research is finding that cold fronts can be extremely complex. The following Web sites offer details, some highly technical, about cold fronts above the ground that often trigger heavy rain and thunderstorms well ahead of surface cold fronts. The links also have information about atmospheric gravity waves.
Ocean waves are examples of gravity waves.
In the atmosphere, gravity waves cause up and down air motions and air pressure changes that can't be felt by humans or detected by many weather instruments. But, they can cause bursts of snow or rain. The links below have more information on complex fronts and gravity waves, but are technical.