Extract from the weather journal

Clouds

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Clouds provide a valuable insight into short-term trends in the weather and are identified according to their form and height. Ten principal types and 27 sub-types are recognised, but the five main groups are: cirrus: feathery or fibrous (pictured below) stratus: stratified or in layers cumulus: heaped (pictured bottom left) alto: middle, and nimbus: rain. Some additional terms for cloud types are: lenticularis: lens shaped; occurs where air currents are undulating sharply in the vertical, as sometimes occurs on the lee side of mountains. mammatus: hanging protuberances - like udders - on the underside of clouds. uncinus: hook shaped; applied to cirrus; often shaped like a comma.