Download Fronts - hrsbstaff.ednet.ns.ca

Fronts
Fronts
•
•
•
Air masses move according to global winds and currents.
The area between two air masses is known as a front.
Meteorologists have determined four main types of fronts: Cold, warm,
stationary and occluded.
Cold Fronts




Cold air mass reaches a warm air mass.
Because the cold air is more dense then the warm air, it pushes the warm air
upwards.
Cumulus clouds or cumulonimbus clouds are often seen.
Cold fronts often bring rain, strong storms or tornadoes.
p. 33: Figure 1.21
Description of a cold front:
Warm Fronts




A warm air mass reaches a cold air mass.
Warm air rises slowly over the cold air mass.
Usually forms stratus and/or nimbostratus clouds that carry light rain or snow.
Once the air mass has passed, the temperature tends to be warmer then before.
p. 33: Figure 1.21
Description of a warm front:
Stationary Front:



A cold mass of air and a warm mass of air are in contact with no movement.
Warm air rises and condenses to form stratus clouds and usually rain.
The front can be stationary for many days.
p. 33: Figure 1.21
Description of a stationary front:
Occluded Front




A cold front reaches a warm front and moves very slowly. The two air masses
are blocked.
Many types of clouds are seen.
Occluded fronts generally bring a long period of hard precipitation.
Occluded means “to block”
p. 33: Figure 1.21
Description of an occluded front:
Please complete the following questions:
1. What is a cold front?
2. Name two ways that a cold front differs from a warm front.
3. What types of fronts bring about a long period of precipitation?
4. Draw the symbols for the following frontal systems: cold, warm, stationary and
occluded. (page 63, Table 2.2)
5. Review Questions - p. 34 #’s 13-16