BEHAVIOR PATTERNS OF NEW ENGLAND HAILSTORMS 
~@' 
(1.0K FT 15.5 K FT 
363 
-5.9°C 
-——25: MI 
220K FT -17.3°C 27.0KFT 
-29.0C 3I1.5KFT ~39.0 C 
@Mcainit Ccains MWecaing 
REFERENCE POINT AT 
INTERSECTION 
OF GRID LINES 
JULY 30,1957 Do 
-—3 MI 
36.0 KFT -49.5°C 
Fie. 12—Echo areas observed in a young growing hailstorm; Gain 1 
shows the weakest echo; Gain 9 the strongest; the arrows are not direction 
vectors; they are for orientation; note the scale change at the highest alti- 
tude; the reference point denotes the location of hail which fell as the 36 k 
ft areas were being photographed 
cy cn Ae! 152 
R—-% 1538+ (FIRST ECHO") 
o—2 1545+ 
x 91 
HEIGHT HEIGHT 
(Kft) (Km) 
20 Ga 
3.0 
lo 
or ' 0 Oo -200 
AREA (Km?) 
Fig. 13—Areas enclosed by decade values of Z, 
as a function of height, in the growing hailstorm 
ilustrated in Fig. 12. (July 30, 1957, D. storm) 
equivalent Z of all of the areas at the several 
gain settings. As many as eight gain settings were 
used to minimize interpolation errors. 
Some of the results are shown in Figures 13 
and 14. The solid curves in Figure 13 relate to 
the areas of Figure 12; the observation started at 
15h45m and ended at 16h02m. The dotted curve 
is the first echo, measured between 15h38m and 
15h40m. The growth both in area and in inten- 
sity 1s almost explosive. Note the two regions of 
50 Tn rr 1 T_T annys2 
* -K 1538+ (SOON X~__ x 
AFTER FIRST TORNADO) =a He 
O—® 1730+ (aT cane ~ 
CONCLUSION OF FINAL TORNADO) aw By | 
40F N x 122 
Nx \ 
\ t 
| 
I 
I 
30 
mi 
HEIGHT { HEIGHT 
(K ft) i (Km) 
20k Ne dhe 
lo 
yi 
k 
, 
oF 430 
oO — ey wt (EN Se 
' 10 100 1000 
AREA (Km?) 
Fic. 14—Areas enclosed by decade values of Z, 
as a function of height, at two stages in the life 
cycle of a tornado-producing storm. (July 11, 1958) 
maximum intensity in both observations. The 
lower one rose at the rate of 550 ft/min, the upper 
one at 620 ft/min, assuming the corresponding 
regions to be related. The lower maximum rose 
through the 0°C level at approximately 15,000 ft. 
The upper maximum rose to a level where the 
temperature was —39°C. 
Two of the five area-height measurements of 
