Mrs. Wharton’s Science Class Air Masses and Fronts Mrs. Wharton’s Science Class

What is an Air Mass? -A large body of air that takes on the characteristics of the area over which it forms -properties of temperature and moisture content are similar in any horizontal direction -Usually cover hundreds of thousands of square miles

Naming Air Masses Air masses are named by combining their temperature and moisture characteristics: Moisture: Dry: Continental (c) Moist/Humid: Maritime (m) Temperature: Warm/Hot: Tropical (T) Cool/Cold: Polar (P) Extremely Cold: Arctic (A)

Types of Air Masses warm, humid air mass: maritime tropical (mT) warm, dry air mass: continental tropical (cT) cool, humid air mass: maritime polar (mP) cold, dry air mass: continental polar (cP) Extremely cold, dry air mass: arctic (A)

Where are the air masses in the US?

Air masses of North America Maritime Polar Continental Polar Maritime Polar Continental Polar Continental Tropical Maritime Tropical Maritime Tropical Air masses of North America

What happens when 2 air masses meet?

What is a Front? The narrow region separating 2 air masses of different densities The type of front which develops depends on the types of air masses involved.

4 Types of Fronts Cold Warm Stationary Occluded

Cold Fronts Cool dense air displaces warm air and forces the warm air up along a steep front. Usually produces clouds, showers, and sometimes thunderstorms

Cold fronts are like snow plows Clouds form mT cP

Warm Fronts Advancing warm air displaces cold air that produces a gradual frontal slope rather than a steep boundary Characterized by extensive cloudiness and precipitation

Stationary Fronts Occur when a cold and warm air mass are in contact but neither are advancing at that boundary. Cold Air Warm Air

Occluded Fronts When cold air mass moves so rapidly it overtakes a warm front and wedges the warm air upward Precipitation common on both sides of the front

Lets Review… What are the types of air masses? (think about temperature and moisture content) What are the 4 types of fronts? How does each of the fronts look on a weather map?