Air Masses and Fronts Page 490 - 495

Air Masses An air mass is a large body of air with similar temperature, humidity and air pressure. Air masses take on the properties of the areas they form over.

Humidity Whether an air mass is humid or dry depends on whether it formed over water or land.

Air Masses-- If they form over the ocean, they are moist. We call these _maritime (m)____ If the air mass forms over land, they are dry. We call these _continental (c)__

An air mass’s temperature depends on where it’s formed. N. Pole An air mass’s temperature depends on where it’s formed. Equator

Air Masses If they form over the polar latitudes, they are cold. We call these __polar (P)____ If the air mass forms over the tropics, they are warm. We call these __tropical (T) ___

Putting them Together cP mP mP mT mT cT mT

Label your diagram

Fronts A front is the boundary between 2 air masses. Fronts are classified by the kind of air mass (warm or cold) that is replacing the other. If a warm air mass is coming in to replace a cold air mass that is called a Warm Front. If a cold air mass is coming in to replace a warm air mass that is called a Cold Front.

Weather Front Symbols ????Which is Which????

Warm Fronts

Warm Fronts Warm air coming in to replace cold air. Warm Fronts bring drizzly rain and are followed by warm, clear weather. This is the weather map symbol for a Warm Front

Cold Fronts

Cold Fronts Cold air moves under the less dense warm air. Cold Fronts move quickly, bring thunderstorms, heavy rain or snow and cool weather follows. The weather map symbol for a Cold Front is:

Stationary Fronts

Stationary Fronts A cold air mass meets a warm air mass, but neither have enough force to move the other. The front stays in place. Cause several days of cloudy, wet weather in one place. The weather map symbol for a Stationary Front is:

Occluded Fronts

Occluded Fronts Forms when a warm air mass is caught between two colder air masses. Occluded Fronts have cool temperatures and bring large amounts of rain and snow. The weather map symbol for an Occluded Front is:

Fronts form along areas of __low____ pressure Fronts form along areas of __low____ pressure. Low pressure = _inclement___ weather.

Looking at this satellite image of cloud coverage, can you guess where a front might be found?