Download 1. Cold front

Fronts
4 different types:
1. Cold front
2. Warm front
3. Stationary
4. Occluded
Fronts are the basic building blocks of
weather systems.
Fronts occur where two large air masses
collide at the earth's surface.
Each air mass has a different temperature
associated with it.
“No matter which air mass pushes, the
warmer, less-dense air will always be pushed
over the cooler, dense air. The result is that
the weather changes.” Pg 380 Science Book
Fronts
1. Cold front
The cold front moves in the direction of the
triangles.
Cold fronts occur when heavy cold air
displaces lighter warm air, pushing it upward.
“The colder, denser air slides under the
warmer, less dense air.” Pg 380 Science
Book.
These fronts are fast moving and bring
stormy weather and heavy precipitation
followed by clearing skies and higher
pressure.
Fronts
2. Occluded Fronts
The occluded fronts move in the direction of the semi-circles.
“If a cold front advances more rapidly than a warm front before it, the cold
front may advance and push the warm air mass forward, up, and over the
cold air mass it was advancing on — this condition is known as an
occluded front.”
These fronts usually produce light rain or other precipitation.
Fronts
3. Stationary
The stationary front is not moving.
A stationary front is the boundary between two air masses that are not
moving against each other.
These fronts tend to stay in an area for a long period of time, often
bringing long periods of precipitation and clouds.
Fronts
4. Warm front
The warm front moves in the direction of the
semi-circles.
Warm fronts occur when warm air replaces
cold air by sliding over it.
The fronts usually move slowly and bring
steady rain or snow over many days.