<- CUMULONIMBUS 



Code 9 



L3: Cumulonimbus with tops lacking clear-cut 

 outlines but distinctly not cirriform or anvil- 

 shaped; with or without cumulus, strato- 

 cumulus, or stratus. 



These are cumuliform clouds of great verti- 

 cal development with tops composed in part 

 at least of ice crystals, the presence of which 

 is revealed by a partial or general indefinite- 

 ness of previously well-defined "cauliflower" 

 tops. 



(See L9 for the coding of cumulonimbus 

 having clearly fibrous tops.) 



<- STRATOCUMULUS 



Code 6 



L4: Stratocumulus formed by the spreading out 

 of cumulus; cumulus also often present. 



<- STRATOCUMULUS 



Code 6 



L5 : Stratocumulus not formed by the spreading 

 out of cumulus. 



This includes a wide variety of aspects of 

 stratocumulus, ranging from thin clouds at a 

 single level with semitransparent parts or 

 even clear spaces, to the dark and menacing 

 clouds, often at two or more levels, immedi- 

 ately before or after precipitation. Code 6 

 applies only in the absence of fractocumulus 

 of bad weather, cumulus, or cumulonimbus. 

 If stratus and stratocumulus are both present, 

 code 6 applies while stratocumulus is 

 dominant. 



184 



H. O. 607 



