HAILSTORM STRUCTURE VIEWED FROM 32,000 FEET 327 
Fie. 3 
more representative temperature sounding for 
mid-day (radiosonde released one to two hours 
after time of maximum temperature) would lie 
in between the Denver and Scotts Bluff curves 
in the lower layers. A dry adiabat drawn from 
the point of intercept of the storm cloud base 
(15,000 ft MSL, 600 mb by measurement from 
the photographs) and the Scotts Bluff sounding 
reaches the surface at a temperature of 34°C. 
The moist adiabat from the cloud base intercept 
crosses through the isothermal layer at 34,000 
ft (266 mb). 
With the structure of the ambient atmosphere 
in mind, a closer look will now be taken of 
the large storm masses that developed during 
the afternoon of the 11th. In the upper middle 
part of Figure 2, a large storm is just beginning 
to produce rain at the ground. Almost the whole 
perimeter of the cloud shadow can be seen, in- 
dicating only a few hydrometeors below cloud 
base. This storm has grown, however, to above 
40,000 ft and a large volume of cloud and other 
hydrometeors have been blown downstream in 
the strong upper winds to form a large anvil with 
maximum horizontal spreading at the upper iso- 
Left T-11 Photo 107, looking east 
thermal layer (33,000-35,000 ft). Another sim- 
ilar storm appears in the upper left but is largely 
obscured in this picture by lower, nearer Cumu- 
lus. 
A third storm, the one to be studied here in 
detail, appears on the right side of Figure 2. 
A more complete view of the western end of 
this storm, (Fig. 5), shows several interesting 
features. (The dark vertical line in the upper 
part of the picture is one blade of the aircraft 
propeller.) Figure 6 should be referred to when 
studying Figure 5. Figure 6 was traced from 
photographs with the use of a Canadian grid tech- 
nique and by triangulation from several pictures. 
Note that because of the varying distances from 
the flight path, this tracing is divided into three 
parts with three different scales. The upper and 
left parts are from Photo 90, the lower right 
from Photo 89. 
The features of interest will be discussed from 
the top down. The portion of the cloud above 
flight and cirrostratus level reaches some 10,000 
ft into stable air; individual cloud elements (bub- 
bles) do not greatly outrun their neighbors, giv- 
ing the whole cloud a rather rounded top. The 
