1. AIR MASSES
Large parcel of air with the same characteristics of temperature and moisture throughout.
Lower case “c” indicates a continental air mass. These form over land and are dry.
Lower case “m” indicates a maritime air mass. These form over ocean water and are humid.

2. Naming Air Masses Upper case “P” means Polar-indicates a cold air mass
Upper case “T” means Tropical-indicates a warm air mass. SO..you mix and match to get 4 air masses:
mT (maritime tropical-humid and warm)
mP (maritime polar-humid and cold)
cT (continental tropical-dry and warm)
cP (continental polar-dry and cold)

3. Source Region
Where an air mass forms and gets its characteristics…for example, an air mass that forms over the south Pacific would be a mT air mass.

5. Fronts Where 2 different air masses meet, a front forms.
At a front, there is always some precipitation, because the warmer air mass rises, cools and reaches the dewpoint temperature.

6. Cold Fronts Cold air moves into warmer air
precipitation is sudden and heavy, but brief in duration. It is cooler but clear after the front passes.
The shape is 90 degrees at the ground-clouds are tall.

7. Cold Front Symbol
Looks like little triangles that point in the direction of movement of the front (think icicles).
(This would be a cold front moving south)

8. Warm Front Warm air moves into cooler air
precipitation is light, but may last for days.
Angle is 45 degrees at the ground and clouds are flat (stratus)

9. Warm Front Symbol Little half-circles show direction of movement.
(This would be a warm front moving south)

10. Stationary Fronts Just stalled in one place for days
warm-front like weather

11. Occluded Front
A cold front is behind a warm front and catches it and lifts the warm air between right off the ground. (“occluded” means blocked-warm air is blocked from the ground.
Warm front-like weather.

12. Occluded Front Symbol

13. Again, the symbol indicates direction
Again, the symbol indicates direction. (This is an occluded front moving northeast.

14. Comparing Warm and Cold Fronts

15. September 26, 2017