By Manuel Rodriquez
A front is the transition zone between two air masses of different density. Fronts extend not only in the horizontal direction, but in the vertical as well. When you are referring to the frontal surface (or frontal zone), we referring to both the horizontal and vertical components of the front.

There are four types of fronts:
1. Cold Fronts
2. Warm Fronts
3. Stationary Fronts
4. Occluded Fronts

Cold Front
aaaaaa.gifA cold front is defined as the transition zone where a cold air mass is replacing a warmer air mass. Cold fronts move from northwest to southeast. The air behind a cold front is noticeably colder and drier than the air ahead of it. When a cold front passes through, temperatures can drop more than 15 degrees within the first hour.

Warm Front

A warm front is defined as the transition zone where a warm air mass is replacing a cold air mass. Warm fronts generally move from southwest to northeast and the air behind a warm front is warmer and more moist than the air ahead of it. When a warm front passes through, the air becomes noticeably warmer and more humid than it was before.

Warm Fronts contain more water vapor than , A cold front

Stationary Front
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When a warm or cold front stop moving it makes a stationary front. once it happens its forward motion, it once again becomes a warm front or cold front. A stationary front is happened by showing blue and red lines with blue triangles pointing towards the warmer air and red semicircles pointing towards the colder air.

Occluded Front

A developing cyclone typically has a preceding warm front (the leading edge of a warm moist air mass) and a faster moving cold front (the leading edge of a colder drier air mass wrapping around the storm). North of the warm front is a mass of cooler air that was in place before the storm even entered the region.