A cold front occurs when dense, cooler air pushes under less dense warm air, often producing severe weather like heavy rain or snow. A warm front happens when less dense warm air rides over more dense cool air, beginning with cirrus clouds then stratus and light to moderate rain followed by warmer weather. A stationary front is the boundary between two air masses that are not displacing each other and results in consistent weather until a force makes the fronts move.

1. A cold front occurs when a denser air mass pushes
under a less dense air mass.
• Move quickly
• Produces cumulus clouds first.
• Often produces severe weather, heavy rain,
snow, thunderstorms.
• Cooler, drier air follows
A warm front happens when a less dense air mass rides
up over a denser air mass.
• Warm air moves over cold air.
• Begins with cirrus clouds, followed by stratus.
• Produces light to moderate rain.
• After it passes, warmer weather comes.
When two air masses come together, but neither
displaces the other, the boundary between them is
referred to as a stationary front.
• The weather remains the same until a force
makes them move