76 INSTRUCTIONS TO MARINE METEOROLOGICAL OBSERVERS 



Cumulonimbus clouds generally produce shoAvers of rain or snow 

 and sometimes of hail or soft hail, and often thunderstorms as well. 



If the whole of the cloud cannot be seen, the fall of a real shower 

 is enough to characterize the cloud as a cumulonimbus (fig. 27). 



Even if a cumulonimbus were not distinguished by its shape from 

 a strongly developed cumulus, its essential character is evident in 



