1. Meteorology Air Masses & Fronts

2. Reference
From the Ground Up Chapter 6.6 & 6.7: Air Masses & Fronts Pages

3. Introduction
Giant air masses move around with the winds and rotate around pressure systems to bring different weather to areas.
It’s important to know what types of air masses and fronts exist, how they form, and what kind of weather they will cause

4. Outline
Air Masses
Fronts

5. Air Masses
Large section of troposphere with uniform properties of temperature and moisture in the horizontal
May be several thousand miles across
Takes on properties of surface over which it forms (known as Modification)

6. Classifications Classifications
Continental Dry c
Maritime Moist m
Arctic Cold A
Polar Moderate P
Tropic Warm T
Main types in North America in winter = cA, mA, mP
Main types in North America in summer = mA, mP, mT

7. Air Masses Cold Air Mass Warm Air Mass Stability Unstable Air
Turbulence
Turbulent
Smooth
Visibility
Good
Poor
Clouds
Cumulus
Stratus, Fog
Precipitation
Showers, Hail, Thunderstorms
Drizzle

8. Fronts Transition zone between two air masses Cold Front Warm Front
Slope
Steep 1:50
Shallow 1:200
Weather
Severe (unstable)
Mild (stable)
Clouds
Cumulus
Stratus
Winds
Veer
Precipitation
Showers
Steady, Storms
Temperature
Cools
Warms

9. Fronts Cold Front Leading edge of advancing cold air mass
Faster the front, the more severe the thunderstorm

10. Fronts Warm Front Trailing edge of retreating cold air mass
Indicated by high to low stratus clouds

11. Other Fronts Stationary Front Occluded Front (AKA Occlusion)
Cold air neither advancing nor retreating
Occluded Front (AKA Occlusion)
Cold front overtakes warm front, lifts warm air up
Trowal (Trough of Warm Air Aloft)
Warm air lifted by occluded front

12. Next Lesson
4.7 – Meteorology Precipitation, Fog & Thunderstorms From the Ground Up Chapter 6.8, 6.9: Pages