From The Developers...

Moving into more advanced topics, here we use an animation to show how precipitation typically develops along the leading edge of a cold front.

Precipitation Along a Cold Front
by lifting of warm moist air ahead of it

The animation below is a vertical cross section depicting the development of precipitation ahead of and along a cold front. The surging blue region represents the cold air mass behind the cold front (solid blue line) and the yellow areas indicate the warm moist air mass ahead of the front.

** Press "Reload" to restart the animation **

As the cold air mass propagates, it lifts the warmer less dense air ahead of it (red arrows). The air cools as it rises and the moisture condenses to produce clouds and precipitation ahead of and along the cold front. In contrast to lifting along a warm front, upward motions along a cold front are typically more vigorous, producing deeper clouds and more intense bands of showers and thunderstorms. However, these bands are often quite narrow (a couple hundred kilometers across) and move rapidly just ahead of the cold front.

cold fronts
Terms for using data resources. CD-ROM available.
Credits and Acknowledgments for WW2010.
Department of Atmospheric Sciences (DAS) at
the University of Illinois at Urbana-Champaign.