Welcome to the official site of the World Meteorological Organization’s (WMO) International Cloud Atlas. This Atlas describes the classification system for clouds and meteorological phenomena used by all WMO Members. The classifications also describe meteorological meteors other than clouds – hydrometeors, lithometeors, photometeors, and electrometeors. Read More
The sections, paragraphs and subparagraphs of this manual that together comprise Annex I to the Technical Regulations (WMO-No. 49) have the legal status of standard practices and procedures; they are enclosed in gray-shaded boxes, like this example.
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