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September 30, 1979 STORM-TRACK Vol. 2, No. 6

3415 Slade Court $2.10/year Bi-monthly
Fairfax, Virginia

Here is an address change for a previous Roster entry:

Name Address Chase country-range
Randal Zipser 1815 – C, Twisted Oak Drive
Norman, Oklahoma 73071

FUNNEL FUNNIES – It Isn’t Easy to Focus with an Air-Conditioned Camera

VI. FEATURE – The Roar of a Tornado When None Was Seen [by David Hoadley]
Although I have seen and photographed over 60 tornadoes and funnels, I’ve only heard the
distinctive roar once, and there was no visible tornado at that time. Of the other storms, I’ve
been within — mile of one funnel and within l-2 miles of three tornadoes, one funnel and a small,
rotating CB base. Two of the three tornadoes were at least F3 based on recorded damage or diameter
of vortex-ground contact. On each occasion, I observed them from outside of a car or from inside with
an open window- but heard no roar or otherwise unusual sound. On all but one of these six
“close encounters,” I was in little or no rain. From these few experiences, it appears that if the
roar can be heard the listener is very close -perhaps within 3/4 of a mile.

The one time that I did hear the roar was on May 22, 1968. A NE-SW

front. lay from central Kansas to NW Oklahoma and then to NE New
Mexico. The frontal demarcation was sharply defined by sensibly
cooler air and a 180 deg windshift from NE to SW, just east of the
front. My surface map for 1300 CDT that day shows a well organized
971 mb low in NE New Mexico that dominated the pressure pattern and
winds to Shreveport, La. and to Des Moines, IA. I drove ENE from
Gage, OK to Hazelton, KS, then E to Caldwell and back to 12-14
miles west of Caldwell. En route I watched the initial buildups some
small and extremely turbulent near Hopeton, OK. I saw the
first sustained cell build to a small anvil at 1717 CDT NE of
Bryon, 0K. It was only minutes afterward that I phoned the Wichita
Weather Bureau radar operator to inquire as to size and movement of
this cell. He reported nothing on radar, and I learned an early
lesson -that radar (at least in 1968) didn’t detect early stage,
potentially severe CBs, which were otherwise evident to the
experienced observer.

At 1900 CDT, I photographed the second cell to build and
sustain itself -from 8 miles S of Hazelton, KS. It was this
cell that very likely produced the isolated but very strong
cell below, which contained a well organized counterclockwise
rotating hole. After driving to Caldwell and
overcoming the problem of cold lens condensation shown in
Funnel Funnies, I charged to a location 12-14 miles W of
Caldwell. At 2010 CDT, I photographed this base until it
gradually broke up about 15 minutes later I was looking W at
this rotation and heard a distinct, loud and continuous roar
(as hundreds of jet planes high overhead). My recollection
is that Wichita radar recorded a cloud top briefly to 67,000
feet (if not this, it was at least 57,000 feet) and higher
than anything else in the area. The roar continued steadily
and faded slowly as the cell began to break up.

At this point I noted something quite interesting. Although initially assuming the source of the
sound to be from this rotation, I slowly turned my head from side to side to try to confirm it. I
was surprised to discover that it seemed to become omnidirectional! Though I tried to localize the
source, fully turning my head 180 deg and overhead, the apparently obvious source could not be
confirmed. I can only conjecture that the overcast produced an echo chamber effect, making source
determination difficulty I will return to this in the next paragraph, with some comments on needed
studies on tornado sounds. The earliest reported tornadoes were 7 and 18 minutes later (2017 and
2028 CDT) and 25 miles NE of this location -near Wellington, KS. At the time of the initial
occurrence, the roar W of Caldwell had almost entirely ceased. At no time did I observe either a
vortex cloud or any dust or debris on the ground beneath the rotating hole -despite excellent
visibility, with low backlighting under the cell. The rotating hole in the middle of the base was
illuminated, apparently by, higher opening in cloud. Regarding the source of this sound, the
adjacent diagram suggests a possible explanation.

Note that a low (10-15,000 feet) and dense anvil was overhead, extending eastward from the
rotating hole- cell, and merged with heavy CB bases with moderate to heavy rain from NE-SE. Light
to moderate rain fell from NNW-NE. The CB base, easterly, was about 10-15 miles distant,
Consequently, I was in a generally clear pocket with clouds or precip from W-N-E. Wichita radar
did confirm a hook echo in this formation at the time of my observance. If the sound were near to
the ground -in the rotating hole, I would expect greater attenuation of the echo reflected from
behind ms. However, since the intensity of the sound was identical from all sides, I would
conclude that the source came from much higher up (perhaps 20-30,000 feet). This should be
expected — the closer the primary sound track is to its reflected track. I am obviously no
acoustics expert and appreciate that many other factors may explain such a phenomenon. However,
this seemed most plausible to me. What do you think? Write Storm Track and let me know!

Such occasions — and subsequent conversations with Dr. John Stanford of Iowa State University -have
suggested to me that much more research needs to be done on the acoustical properties of
tornado sounds and what they tell us about, the dynamics of the storm. Some questions which occur
to a layman such as myself:

(1) Is the sound primarily a result of wind shear or is it, also produced by hail entrainment and
collision around the vortex, continuous lightning or ground debris?
(2) Does the “sound generator” begin high in the tornadic cell and then descend as the vortex
takes shape?
(3) Does it sound differently at the same time from different, locations?
(4) What does the absence of sound signify; when and why? Dr. Stanford reported that some farm
families immediately next to the huge Ames, Iowa tornado of June 13, 1976 reported no tornado
(5) Is the sound loudest at the tornado’s onset in the cloud or on the ground?
(6) What is the significance in changes of pitch, tone, etc ? It would appear that inconsistencies
in the experience of witnesses to tornadic sounds warrants a lot more research in the area than
this layman is currently aware of. If you have had interesting sound experiences, by all means
write to Dr. John Stanford, Physics Department, Iowa State University, Ames, Iowa 50011. Also, let
ST readers know.
Next issue is our annual poetry venture. Send your favorites if you want them included.

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