23. Heavy or Swelling Cumulus and Low Ragged Clouds of Bad 

 Weather, L9. 

 A large mass of cumulus has covered much of the sky and the ragged 

 edges of fractocumulus are seen in the direction toward which the 

 clouds are moving. These low ragged clouds are distinguislied by their 

 association with a cumulus mass and must not be coded L^ which is 

 reserved for low ragged clouds below a sheet of altostratus or nimbo- 

 stratiis (Pis. 15, 16, and 17). (Photo at Washington, D. C, by W. J. 

 Humphreys.) 



24. Heavy or Swelling Cumulonimbus and Low Ragged Clouds of 

 Bad Weather, Lg. 



In this picture the cumulonimbus has spread over the sky wdth a 

 shower in the left half of the picture. A ragged mass of dark fracto- 

 cumulus appears in the upper right corner. Whether the main cloud is 

 cumidonimbus or a heavy and swelling cumulus, the low ragged clouds 

 are coded Xg. Clouds with a mamm.atus structure may appear; after 

 they have become disassociated with the cumulonimbus, and the 

 latter is no longer in e^ddence, code X4 should be used instead of Lg. 

 (Anonymous.) 



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