CONTENTS 



Page 



Introduction iii 



Names and heights of clouds 1 



Classification 1 



Definitions and descriptions of the forms of clouds 3 



Cirrus 3 



Cirrocumulus 4 



Cirrostratus 4 



Altocumulus 5 



Altostratus 7 



Stratocuinulus 8 



Stratus 10 



Nimbostratus 10 



Cumulus 11 



Cumulonimbus 12 



Varieties and details 13 



Entry of clouds on record forms 15 



Abbreviations 15 



Amount and direction of motion 16 



Observation of clouds for coded messages 17 



Code tables 19 



The state of the sky and the evolution of the clouds 21 



Code specifications 22 



Lower clouds 22 



Middle clouds 25 



Upper clouds 29 



Key to identification of cloud code types 32 



Sky and clouds in a typical disturbance 35 



Photographs with descriptions 36 



Aerial views of clouds 90 



(II) 



