Each spring, cold fronts moving south from the North will collide with warm, humid air streaming in from the Gulf Coast, leading to severe thunderstorms with lightning, torrents of rain, hail, and occasionally, tornadoes.

Sam Perugini, a meteorologist at Pennsylvania State University, said that a strong cold front and a warm, humid air mass had collided to provide the breeding ground for the storm system.

I can shop till the cow tchotchkes come home, load up on grog lite and doze by a wax-log fire, dreaming of blizzards past and (if the right fronts collide over a sympathetic dew point) yet to come.

In this case, by the time the front of the ladder collides with the back door, the back of the ladder does not know it yet, so it keeps moving forwards (and the ladder "compresses").

For example, a box-like front (relative to the object's motion) will collide with the medium's particles at a high rate, transferring more momentum from the object to the fluid than a more aerodynamic object.

In the spring, cool fronts moving south from Canada collide with warm, humid air streaming in from the Gulf Coast.

Behind the News - An arctic front pushing across the nation's center collided with warm moist air surging north from the Gulf of Mexico, creating freezing rain, sleet and snow across the Southern Plains, the mid-Mississippi River Valley and the central Midwest.

When these cold and warm fronts collide they can result in hurricane force winds that stir up large waves on the Lakes.

The front that was carrying Pacific moisture over the mountains had collided with some supercold air that was blowing down from Saskatchewan, and together the two weather systems became a fast and furious snow machine along Colorado's Front Range.