| Term | Definition |
| water falling from clouds in the form of rain, ice or snow | precipitaion |
| trypes of precipitation | rain, hail, sleet |
| coalescence | when air temperature is above freezing and minute droplets suspend in mid-air collide with bigger droplets. Droplets grow larger until they cannot over come the pull of gravity and finally fall as rain |
| forms when temperature is below freezing and water vapor changes directly to ice without first condensing | snow |
| hail | falling balls of ice |
| water vapor changes directly to ice | sublimation |
| fog | low level stratus clouds |
| when supercooled water droplets (water that is below freezing but has not yet frozen) and ice crystals exist above freezing. The supercooled droplets freezing onto the crystals and crystals grow until they fall | the ice crystal process |
| drizzle | when drop size is at least 1/125 of an inch (0.2) |
| snow and strong winds of 55 mph or higher and temperature is 10 dergrees (Farenheit) lower | blizzard |
| frost | ice deposits when temperature below freezing (32 degrees farenheit) after the dew has formed and dewdrops that freeze |
| drops of water falling in temperatures above freezing | rain |
| sleet | forms when snow passes through a layer of warm air, melts, and then refreezes near the ground |
| beads of water on ground cover | Dew |
| Radiation fog | develops at night when winds are light and the sky is clear (so the earth radiates large amounts of heat) |
| forms when supercooled water droplets fall as rain and turn to ice or ice pellets when they meet colder air | Freezing rain |
| snow flake | starts as a single crystal of snow which forms when water vapor deposits directly on ice onto a grain of airborne dust. crystal formation increases as temperature falls |
| when 'supercooled' rain cools below freezing, but remains a liquid and then hits the frozen ground and instantly forms an ice coat | Rime or Glaze |
| Sleet or Ice Pellets | grains of ice |