In the next class, we will discuss how these ideas relate to satellite sensors. The last thing we looked at was page 285 in the reader. It shows the concept of condensation and evaporation. Like molecules attract one another. In our atmosphere, the temperature is just right for water vapor to condense if temperatures cool enough.
Condensation is water vapor changing to liquid water.
There are lots of water molecules in the air, but they don't connect because they are vibrating too fast and they end up bouncing off each other. If you wanted them to connect you'd have to cool the room until you reached the Dew Point Temperature, or the temperature at which condensation will occur. In order to begin to evaluate weather someone has to make an observation. Looking at any map of tbe North American West coast we see a difficulty in making weather observations of California. Using observation, we agree, our weather here usually comes from the West.