Mr. Hartwell -- F-M Meteorology Cloud Types & Properties
Clouds Formed when moist air is cooled enough to allow saturation & condensation to take place. Saturation: air is completely filled with water vapor Condensation: phase change from gas to liquid
Clouds cont. Different types form based on: Amount of moisture in the air Vertical air temperature through troposphere Character of rising air (speed & location) Approaching weather systems Identified by: Shape Height Composition Character (puffy vs. layered)
Classification—Type #1 Cirrus —feathery, wispy, thin
Classification—Type #2 Cumuliform —puffy, round, pretty
Classification—Type #3 Stratiform —layered, sheet-like, strata=layers (like rocks)
Classification—Type #4 Nimbus —produces precipitation
Heights (HIGH): CIRRUS (Ci) Cirrus — made of ice crystals Align with upper level winds Indicate fair weather conditions Aka: Mare’s Tails (look like horse’s tails)
Heights (HIGH): Cirrocumulus (Cc) Cirrocumulus — ice crystals Occur in moist & unstable air (aloft) Appear with precip.- causing weather (warm fronts) Aka: “Mackerel sky, not three days dry”
Heights (HIGH): Cirrostratus (Cs) Cirrostratus — ice crystals Common in winter with precip.- causing weather Produce sun dogs & halos
Sun DogHalos
Heights (Middle) : Altocumulus (Ac) Occur in moist air that is lifting Fist-thumb- pinkeytip rule Altocumulus = thumb size Signals approaching storm system
Heights (Middle) : Altostratus (As) Layered; liquid water Gray to pale blue Occurs where moist air is rising slowly Just ahead of rainy weather
Heights (Low) : Cumulus (Cu) Puffy, white, pretty Indicates fair weather Well-defined bases Caused by humid air rising in bubbles
Heights (Low) : Cumulus Congestus Aka: towering cumulus Atmosphere is very unstable Indicates stormy conditions later in the day
Heights (Low) : Status (St) Sheet cloud; layers Hovers just above the ground (was fog?) No precip., but may be misty
Precipitating Clouds: Nimbostratus (Ns) Same as stratus, just precipitating Precedes warmth (occur before warm fronts)
Precipitating Clouds: Cumulonimbus (Cb) Thunderstorm! Can poke into stratosphere Associated with severe weather Anvil shape tops with mammatus clouds
Precipitating Clouds: Cumulonimbus (Cb)
Mammatus cloud (below) Anvil shape (above)
Miscellaneous: Contrails
Miscellaneous: Fallstreaks Formation: Sublimation of falling ice crystals carried by winds aloft