Because with any gas, air expands and rises when it is heated (by the Earth's heat/suns reflection in this case) so the cold air is at the bottom.
When cold air masses push against warm air masses, a cold front is formed. This results in the warm air being forced upward, leading to the potential for thunderstorms and other severe weather patterns.
The cold air mass is denser than the warm humid air, so it forces the warm air to rise rapidly. This can lead to the formation of clouds, precipitation, and possibly severe weather such as thunderstorms or tornadoes as the warm air condenses and cools.
A passing cold front typically decreases air pressure. Cold fronts move in and push warm air upward, creating lower pressure at the surface due to the rising air. This drop in pressure can lead to unsettled weather conditions.
a cold air mass comes in under a warm air mass
At the boundary lines of air masses with different densities and/or temperature. There are cold fronts, warm fronts and occluded fronts. Cold fronts usually move faster than warm fronts.
Cold air is denser than warm air. Which allows it to slide under that warm air and displace it.
Cold air is more dense than warm air and therefore heavier
Stationary
When cold air masses push against warm air masses, a cold front is formed. This results in the warm air being forced upward, leading to the potential for thunderstorms and other severe weather patterns.
a front causes rain or a storm along the line where 2 masses meet they push against each other
What is formed? Well, cold fronts obviously produce colder temperatures. They cause cold air to move under warm air and then they push the warm air up. Cold fronts move very quickly and they bring thunderstorms, heavy rain, or snow. They produce colder temperatures because the air mass behind the cold front is cooler and drier than the air mass that it is replacing.
A stationary front forms when two air masses push against each other without moving, resulting in prolonged periods of cloudy and wet weather as the warm and cold air interact. This can lead to persistent precipitation along the front.
The cold air mass is denser than the warm humid air, so it forces the warm air to rise rapidly. This can lead to the formation of clouds, precipitation, and possibly severe weather such as thunderstorms or tornadoes as the warm air condenses and cools.
it is very cold
When two fronts push against each other, it can lead to the formation of a stationary front. This results in cloud formation and precipitation, as warm and cold air masses interact along the boundary. The intensity of the weather associated with the fronts depends on factors like temperature contrasts and wind patterns.
A passing cold front typically decreases air pressure. Cold fronts move in and push warm air upward, creating lower pressure at the surface due to the rising air. This drop in pressure can lead to unsettled weather conditions.
a cold air mass comes in under a warm air mass