1. Air Masses and Fronts

2. An air mass is a large volume of air in the troposphere with similar characteristics of… ADD HERE
T = Tropical air masses
c = Continental air masses
P = Polar air masses
Air masses tend to be represented by symbols on a map
m = Maritime air masses
The various symbols for air masses are found on pg. 13 of RT
A = Arctic air masses

3. Air Masses of North America
Continental Arctic
(very cool and dry) cA
Continental Polar
(cool and dry) cP
Maritime Polar
(cool and moist) mP
Maritime Tropical
(warm and moist) mT
Continental
Tropical
(warm and dry) cT
Maritime Tropical
(warm and moist) mT

4. High and Low Pressure Systems
In the Northern Hemisphere, low pressure systems spin… ADD HERE
In the Northern Hemisphere, high pressure systems spin… ADD HERE

5. Fronts A front is… ADD HERE
Severe weather conditions are often associated with fronts.
RT = Pg. 13
There are four different fronts that represent the areas where air masses meet.
Each front is represented by a unique set of symbols and colors.

6. Cold Front In a cold front, an… ADD HERE
The warm air mass is less dense and rises above the cold air mass. The rising air forms large cloud systems associated with severe storms (thundershowers).
Rain is usually associated in regions… ADD HERE

7. Rain is usually associated… ADD HERE
Warm Front
In a warm front, an advancing… ADD HERE
The warm air mass is less dense and rises above the cold air mass. The warm air moves on top of the cold air (like a wedge). A layer of different types of clouds arranged throughout the atmosphere is seen in a warm front.
Rain is usually associated… ADD HERE

8. Cloudy skies and/or rain is usually… ADD HERE
Stationary Front
In a stationary front, an advancing… ADD HERE
The warm air mass is less dense than the cold air mass and rises at the boundary of the front. Sometimes it may take weather patterns a longer time to move across a region due to the opposing movement of the air masses.
Cloudy skies and/or rain is usually… ADD HERE

9. Occluded Front
In a occluded front, an advancing cold air mass overtakes a warm air mass to meet up with another cold air mass. The warm air is forced above both cold air masses and is responsible for cloud development associated with precipitation.
Occluded fronts are associated with… ADD HERE
Very low air pressure and… ADD HERE