CLOUD IDENTIFICATION TABLE:
| Genus | Image | Altitude [feet] | Composition | Indication |
| Cirrus [Ci] |  | > 20,000 ft | Ice crystals | Fair weather; Uniform cirrus indicate an approaching warm front |
| Cirrocumulus [Cc] |  | > 20,000 ft | Primarily ice crystals | In winter, indicate fair, cold weather; At tropical latitudes, Cc may indicate an approaching tropical cyclone |
| Cirrostratus [Cs] |  | >= 20,000 ft | Ice crystals | Signals an approaching warm front if Cs thicken; Forms when layer of air lifted by convergence |
| Altostratus [As] |  | Between 6,500 and 20,000 ft | Water droplets | Signals incoming continuous rain or snow; Occasionally, rain may fall from As |
| Altocumulus [Ac] |  | Between 6,500 and 20,000 ft | Primarily of water droplets | Presence of Ac on a warm, humid summer morning suggest afternoon thunderstorms; Ac form in an unstable layer aloft |
| Stratocumulus [Sc] |  | Generally | Water droplets | Sc generally represent improving weather conditions; During winter, stable weather likely |
| Cumulonimbus [Cb] |  | Up to 50,000+ ft | Mixed phase | Convective/stormy weather in the vicinity; NOTE: Lightning can strike well outside of these clouds - Always remain aware of your weather surroundings |
| Cumulus [Cu] |  | | Water droplets | As long as no vertical development is taking place, Cu indicate fair weather |
| Nimbostratus [Ns] |  | | Primarily of water droplets; can contain ice crystals in sub-freezing air temperature | Ns are precipitation clouds; Ns are accompanied by light to moderate falling precipitation |
| Shelf/Arcus [-] |  | | Water development | Approaching thunderstorm; Form when cool, sinking air from a storm's downdraft spread out ahead of the storm |
| Wall Cloud [-] |  | | Water droplets | Severe weather is occurring nearby; These clouds mean trouble. Wall clouds often rotate and are usually the location where tornadoes form in a thunderstorm |
| Scud/Fractus [-] |  | | Water droplets | If you are seeing scud clouds, that means that a parent thunderstorm clouds is nearby, where rain, hail, gusty winds, and lightning is likely occurring; Rain will very likely start soon |
| Mammatus [CBMAM] |  | Between 30,000 and 50,000 ft | Water droplets; Often mixed phase with ice crystals as well | These clouds occur when moist air sinks into a layer of dry air, creating pouch-like clouds; These clouds signal a nearby, thunderstorm, usually an intense one, and typically appear after the passage of said storm |
| Contrails [-] |  | Between 25,000 and ~60,000 ft | Primarily water droplets; can also contain sulfurous compounds or jet fuel impurities | Contrails form when there is ample moisture in the high levels of the atmosphere and the air is very cold; Short lived contrails may indicate fair weather due to the relatively dry air, and conversely, long-lived contrails may suggest a changing weather pattern (see the Appleman Chart above) |
| Noctilucent [NLC] |  | Between 250,000 and 280,000 ft | Dust particles and water vapor | These polar mesospheric clouds form when temperatures in the mesosphere are below -200 degrees Fahrenheit, causing water droplets to freeze into ice clouds |
