STORM TRACK: January 31, 1981 (Volume 4 Issue 2)

I have had two experiences with roaring sounds that might be of interest to you and your ST readers.

The first was encountered on May 30, 1976 near Jacksboro, Texas. John Weaver and I intercepted the storm from the north, and we found out later that Steve Tegtmeier saw it from the south. Steve didn't hear anything but was never as close as we were. The storm was of the 'dryline' type, in fact it was very small and never had a substantial precipitation shaft. We drove under the storm's base, when it still looked much like Fig. 1. There was little, if any, sound at the time. The storm appeared to be rotating anticyclonically, as the rolls shown in Fig. 1 seemed to be moving as indicated by the arrows. The storm began as a member of a cluster of storms further south, splitting off and moving rapidly north northeastward (apparently a "left-mover"),

Figures 1, 2, and 3

Driving away from the storm, we stopped several times to take photographs. It was at one of these stops, watching the storm to our SWstill appearing much like Fig. 1), that we heard a steady, muted roaring sound. As nearly as we could tell, from a distance of about 3-5 miles to its NE, the sound was coming from the storm's anvil, near where the storm tower joined it from below. We listened in fascination for a time, and then John remembered his tape recorder. By the time we started recording the sound, it had substantially diminished. During the time that we heard it, we could occasionally hear normal thunder sounds that were louder and clearly separate from the continuous roar.

As the storm dissipated, the roaring gradually faded. Fig. 2 shows the last view of the storm, as we were driving away. At that time, we could no longer hear the sound.

Dr. Roy Arnold of the University of Mississippi has analyzed John's tape recording and confirmed the existence of a steady sound, with an acoustic frequency in the range of normal thunder.

The second storm was intercepted by Al Moller and myself on May 28, 1977 in western Oklahoma. When we first approached the storm, north of Erick, it was apparently a strong multicell storm with a wall cloud. It seemed to be diminishing slowly in strength and moving ESE. As it crossed I-40, we heard radio reports of golf ball hail. Since it was the "best show in town," we continued to follow it, even though we could see the base shrinking.

We drove under the storm's weak flanking line and failed to encounter any significant inflow to the storm from the SE, so we considered its severe potential to have disappeared. Finally, we stopped on Hwy 283, SE of Sayre and watched the storm dissipate. It was at this time that we noticed the same sound I had heard with the Jacksboro storm.

In this case, the storm appeared as in Fig. 3. The appearance suggests a right-moving cyclonically rotating storm. Once again, the sound seemed to originate high up in the anvil, near the point where the storm's tower joined it. No recording of the sound was made. Noteworthy is the band of stratiform clouds, wrapping around the front of the storm from the south -at lower mid¯levels. Again, the motion of the rolling convective towers is indicated by arrows on the figure. We left the storm before it dissipated completely but, as in the previously described situation, the sound gradually faded as the storm weakened.

I can offer no explanation for this sound. Finally, my intercept experience agrees with Dave's (ST Vol. 2, No. 6), in that I have never heard any roaring sound with the tornadoes I've intercepted. My closest encounter was with the famous Union City, Oklahoma tornado. A group of us entered the town shortly after the tornado passed through, and the funnel was in its shrinking stage to our SE ( 1-2 mi.). The wind was from the NW, towards the tornado, at the time. See the article in Weatherwise (1974) by Moller, et. al for other details of that intercept.