| A | B |
|---|
| Humidity | measure of the amount of water vapor in the air |
| Relative Humidity | Percentage of water vapor in the air compared to the maximum amount the air could hold and is measured by a psychrometer |
| Psychrometer | two thermometers, a wet-bulb and a dry-bulb |
| Clouds | form when water vapor in the air becomes liquid water or ice crystals |
| Condensation | Process by which molecules of water vapor in the air become liquid water |
| Evaporation | process by which water molecules in liquid water escape into the air as water vapor. |
| Dew Point | Temperature at which condensation begins |
| Cumulus | Clouds that look like fluffy, rounded poiles of cotton and indicate fair weather |
| Cirrus | Wispy, feathery clouds made mostly of ice crystals |
| Stratus | Clouds that form in flat layers and produce snow or rain |
| Fog | Clouds that form near or on the ground |
| Cumulonimbus | Clouds that produce thunderstorms |
| Precipitation | Water that falls from the clouds to the ground including rain, snow, sleet |
| Surface Run-off | Precipitation which travels at the soil surface to stram channels |
| Ground water discharge | movement of water out of the ground |
| Surface tension | Cohension of water at its surface |
| Cohesion | How water molecules attract each other or stick together |
