the line. A recent investigation [Nolen, 1959] 
suggests a close association of tornadic activity 
with this echo pattern. Nolen has appropriately 
named these line distortions ‘line echo wave 
patterns, referred to hereafter as LEWP. 
Two storms in 1958 which exhibited LEWP 
were well documented by data from radar and 
network observers. Detailed analyses of the 
storms were made to determine: the association 
of hail and strong winds with the LEWP; and, 
whether the LEWP was a function of echo 
height. 
Figure § illustrates the radar display on July 
27, 1958, with the LEWP development shown 
at four-minute intervals on normal and reduced 
gain. The total time for development was ap- 
proximately 30 min. The sharp increase in echo 
intensity along the southern extreme is a normal 
product of LEWP development. An RHI cross 
section indicated little or no echo height varia- 
tion through the LEWP. This suggests that the 
line distortion was not a result of vertical growth 
KEY 
4 HAIL 
— WIND DAMAGE 
0.1600 CST , 27 JULY 1958 
STOUT, BLACKMER, AND WILK 
into a steering level of higher wind speeds, but 
rather a consequence of a horizontal discon- 
tinuity in the wind field, in the form of a nar- 
row jet penetration. Analysis of the general 
wind profile, with emphasis on the Peoria rawin- 
sonde observation, provided support to this con- 
clusion. 
Figure 9 is a radar-synoptic schematic of the 
network, hail and wind reports, the LEWP, and 
the wind maxima that occurred on July 27, 
1958. The wind value of 263°, 58 knots, was 
observed at 13,000 ft over Peoria at 18h 00m 
CST. A greater maximum of 245°, 64 knots, 
was observed near the tropopause at 29,500 ft. 
The northerly drift of the LEWP suggests that 
the higher maximum had limited directional 
control; however, the surface wind observations, 
as well as the LEWP, are aligned with the di- 
rection of the lower maximum. 
The second example, August 7, 1958 (see Fig. 
9) supports the LEWP correlation with the 
hail reports. Post-analysis of surface synoptic 
b.0830 CST, 7 AUGUST 1958 
Fra. 9—Mid-tropospheric jet penetration of squall line 
