MICROSTRUCTURE OF STORMS BY RADAR 87 
J —— Edges of echo on 
ANICPS-9 
em 
——-—Level 4 
ree eee | 
Range-corrected 
© 10 20 mies GSS Level 5 
iso-echo contours 
@ level 6 
Fic. 1—Main band of precipitation with smaller areas of heavier rain [A-E] spaced along it at 00h 30m 
EST, October 19, 1957 
small showers which were 15,000 to 20,000 ft in 
height and were about two or three miles in hori- 
zontal dimension. The echoes had a well-defined 
bright band near the 10,000-ft level, but the 
showers were so small it was difficult to tell 
whether the bright band actually extended 
through them or not. 
The signal intensity contours (Fig. 1) show 
areas of more intense rain spaced about 30-50 
mi apart along the line. These are labelled by the 
letters A to E in the figure. The areas A and E do 
not actually show because at the time they were 
out of range of the SCR-615-B radar. However, 
they were observed on previous or subsequent 
contour maps and indicated by the rainfall data. 
The approximate rainfall rates for each intensity 
level in Figures 1 and 2 are as follows: 
Level 3 A be 26 
Rainfall rate (mm/hr) Qn 25) OY E25 
Preceding the main band in each storm was an 
area of lighter rain whose internal structure could 
not be observed in detail by the SCR-615-B 
radar. In the latter part of the storm the broad 
band broke up into an irregular rainfall area 
which showed a tendency to form a series of nar- 
row bands oriented more nearly northeast-south- 
west, as shown in Figure 2. 
Spatial dimensions of storm areas—An attempt 
has been made to reconstruct the details of the 
storm structure by combining the information 
from two radars and the hourly precipitation 
records. The spatial scales or dimensions have 
