18.3 Cloud types and 18.3 Cloud types and PrecipitationPrecipitation

•Clouds are classified on the Clouds are classified on the basis of their form and heightbasis of their form and height– –

18.3 Cloud types and 18.3 Cloud types and PrecipitationPrecipitation

•CirrusCirrus

•Feathery appearanceFeathery appearance

•CumulusCumulus

– Flat base, with rising domesFlat base, with rising domes– ““_____________” structure_____________” structure

18.3 Cloud types and 18.3 Cloud types and PrecipitationPrecipitation

•StratusStratus

•Cloud heightCloud height– High clouds – _________ meters and High clouds – _________ meters and aboveabove

– Middle clouds – ________________ Middle clouds – ________________ metersmeters

– Low clouds – _____________ metersLow clouds – _____________ meters

18.3 Cloud types and 18.3 Cloud types and PrecipitationPrecipitation

•High CloudsHigh Clouds– cirruscirrus– ________________________– ________________________

•All thin and white and made mostly of All thin and white and made mostly of ice crystalsice crystals

18.3 Cloud types and 18.3 Cloud types and PrecipitationPrecipitation

•Middle cloudsMiddle clouds– Use the prefix –______Use the prefix –______

•______________________•______________________

–

•Low cloudsLow clouds– ________________________– ________________________– ________________________

18.3 Cloud types and 18.3 Cloud types and PrecipitationPrecipitation

•________________ clouds – ________________ clouds – “thunderheads”“thunderheads”

•Fog – clouds that form at Fog – clouds that form at ground levelground level– May be caused by _________ or May be caused by _________ or ______________________

18.3 Cloud types and 18.3 Cloud types and PrecipitationPrecipitation

• How precipitation formsHow precipitation forms– Cloud droplets must grow in volume by Cloud droplets must grow in volume by ____________________________

– Cold Cloud PrecipitationCold Cloud Precipitation• BergeronBergeron – relies on 2 processes – relies on 2 processes

– ______________ and ________________________________ and __________________– Water in liquid state below 0 degrees Celsius Water in liquid state below 0 degrees Celsius is supercooledis supercooled

– When air is at 100% humidity it is satured to When air is at 100% humidity it is satured to water, and supersaturated to icewater, and supersaturated to ice

__________________________________________

18.3 Cloud types and 18.3 Cloud types and PrecipitationPrecipitation

•Warm cloud precipitationWarm cloud precipitation – – – ______________________ process______________________ process

•Water absorbing particles remove Water absorbing particles remove water vapor from the air at relative water vapor from the air at relative humidities _________________humidities _________________

•Drops formed are quite large, they Drops formed are quite large, they fall, and coalesce with smaller, fall, and coalesce with smaller, slower dropsslower drops

18.3 Cloud types and 18.3 Cloud types and PrecipitationPrecipitation

• Forms of precipitationForms of precipitation– Depends on the Depends on the __________________________________________________________________________• __________: drops with a diameter of at least 0.5 __________: drops with a diameter of at least 0.5 mmmm

• __________: smaller drops of precipitation__________: smaller drops of precipitation

• __________: solid drops made of 6-sided ice __________: solid drops made of 6-sided ice crystalscrystals

• __________: falling of small particles of ice__________: falling of small particles of ice

• __________: freezing rain__________: freezing rain

• __________: begin as small ice pellets and grow by __________: begin as small ice pellets and grow by collecting supercooled droplets as they fall to the collecting supercooled droplets as they fall to the groundground