Labs / Geography
How Clouds Form
Grab the bubble of air and drag it upward. As it rises it cools, and the moment its temperature meets its dew point a cloud appears at the lifting condensation level. Warm, moist air that keeps rising can turn unstable and tower into a thunderhead — watch the plot to see why.
Tparcel 24.0 °Cbase 1.00 kmRH 60 %unstable — rising
What to try
- Raise the dew point until it nearly matches the surface temperature. Why does the cloud base drop toward the ground?
- Drag the parcel just below the cloud base and let go. Why does it sink back instead of floating away?
- Lift it past the cloud base and release. What makes it suddenly accelerate upward instead of settling?
- Turn off “latent heat above cloud base.” Without the warmth released by condensation, can the parcel still tower?
- Compare Humid tropics with Dry desert. Which one builds a tall cloud, and which barely forms one at all?