1. Air Masses and Fronts

2. Air Masses
Air mass: huge body of air that has similar pressure, humidity, and temperature
Maritime (m) : Forms over water (moist)
Continental (c): Forms over land (dry)
Tropical (T): Forms in the tropics (warm)
Polar (P): Forms in polar regions (cold)
Acquires characteristics of that surface.

3. For example… don’t write this!
If the source region is the gulf of Mexico and the air comes to Long Island…
If it comes from central Canada…

4. Don’t write this 

5. Low Pressure and High Pressure Systems
Lowest pressure in the center
CCW due to coriolis effect

6. Wind blows TOWARD the center Counterclockwise Causes clouds/rain/wind
Low Pressure Systems:
Cyclones
Wind blows TOWARD the center
Counterclockwise
Causes clouds/rain/wind
Lowest pressure in the center
Clockwise due to Coriolis Effect

7. High Pressure Systems: Anticyclones Wind blows AWAY FROM the center
Clockwise
--Clear, dry, sunny conditions
highest pressure in the center
CW due to coriolis effect

8. How Air Masses Move in the US
Prevailing Westerlies Jet Streams Fronts

9. Fronts

10. Cold Front A fast-moving COLD air mass that overtakes a warm air mass
Short period of heavy rain

11. Warm Front A WARM air mass overtakes a slow-moving cold air mass
Gentle rain for a longer time

12. Occluded Front
A warm air mass is caught between two cooler air masses

13. Stationary Fronts
Cold and warm air masses meet, but neither moves the other