CUMULUS CONVECTION AND ENTRAINMENT 
should affect the development of the cloud. The ground 
may be as significant a heat source as the latent heat 
released in the cloud. When this surface heating is con- 
sidered it again appears that an approach lke that 
applied to the Bénard cells may be more fruitful than 
recent attempts to handle entrainment and mixing. 
The author recognizes that there are serious theoretical 
problems in the cell approach. In many respects the 
question of convection is perhaps as complicated as the 
eyclone problem. 
In conclusion, it appears likely that no major progress 
will be made with the forecast problem of cumulus 
convection until more knowledge is gained of the 
mechanics of cloud growth. 
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