1. Air Masses and Fronts Meteorology

2. Air Masses Classified by temperature and humidity –Tropical: Warm, form in tropics, low pressure –Polar: cold, form near poles, high pressure –Maritime: form over oceans, humid –Continental: form over land, dry

4. Fronts Colliding air masses

5. Cold fronts Cold air “undercuts” warm air. Front moves quickly. If the warmer air mass contains enough moisture, possible storms, clouds, rain (vertically developing clouds) followed by clear, cool weather.

7. Warm fronts Warm air “over-rides” cool air. Front moves slowly. If the warmer air mass contains enough moisture, clouds (stratus) and rain may occur for several days followed by warmer, more humid weather.

9. Stationary Fronts Neither air mass has enough force to move the other. Weather depends on moisture content of air masses.

10. Occluded Fronts Most complex front. Involves three air masses: cool, cold, warm.