Gannon kindly reminded everyone that they need to know where the nearest shelter is located. If mobile, they need to be aware of traffic, road conditions and distractions.
A typical tornado begins on a hot, sticky afternoon when large clouds appear in the sky and thunder begins to rumble in the distance. A nearby cloud becomes heavy and dark. The rounded masses underneath the cloud start to boil and twist at random.
But suddenly, the twisting begins to form into a vortex, or whirl, that gradually extends downward. A heavy rain and some hail typically ensue. Bright flashes of lightning are constantly visible. A strange hissing sound is added the rumbling of the thunder.
This is caused by the funnel cloud as it stretches toward the earth. When the funnel finally touches the ground, it stirs up dirt and debris, and the hissing turns into a loud roar that sounds like a thousand freight trains going by. On the edge of the funnel, trees blow down. In the center of the funnel, buildings explode.
Lightning is the biggest killer, so Gannon instructed the firemen to stay in their vehicles. He also made it clear that lightning can strike 15 miles ahead of the storm. He then showed the firemen a number of videos and pictures of recorded tornados.
He also encouraged all in attendance to not use the example of "marbles" when reporting the size of hail, as marbles come in many different sizes. Instead he suggested comparisons to coins, such as half dollars, quarters, dimes, nickels, etc. He also Okayed referring to hail as golf ball, tennis ball and baseball sized.
The firemen learned precisely where they should be, while out watching for storms and tornados. He also stressed the importance of having multiple escape routes planned, as these violent, twisting wind storms, which are usually 300 yards across, can blow 300 miles an hour or more.
Here in southern Minnesota, the air whirls around the center of the storm in a counter-clockwise direction. The whirling air meets near the center of the storm, and then rushes upward with terrific force. In some areas, tornadoes are known as twisters.
The United States Weather Bureau constantly gathers weather information from all parts of the United States. If weather conditions appear favorable for tornadoes, the bureau requests special observations from local observers, radar stations and the pilots of aircraft.
If these observations show that tornadoes seem likely, the bureau issues a warning to the people of the area about the possibility of a tornado. Some communities send observers to hilltops and other vantage points to watch for funnel clouds. When observers sight a funnel, sirens warn the residents to take cover.
