1. Rain or Shine?
Why weather happens.

2. What How do the
happens substance
when and
molecules molecular
are heated? properties
What about change?
when they
cool? THE
CONVECTION
CYCLE!

3. Air Masses
warm, moist cold, moist
warm, dry cold, dry
cold air mass meeting a warm air mass

4. Why does the weather change?
Cold air mass ->
Warm air mass
Warm air mass
-> Cold air mass