Responding to Patterns of Change

Allow students time to answer these questions. Once they have had time to complete their responses, you may want to hold a class discussion on some or all of them.

1. Write three to five statements to summarize what you have learned about the occurrence of tornadoes in the United States.

• During the time period for these data, tornadoes occurred in most states. (In fact, if you look at data for the total number of tornadoes per state each year, you will see that tornadoes occur in all states. In some states, however, tornadoes are infrequent, so the average number is 0.)
• Some states have more tornadoes than other states.
• Tornadoes are more frequent in May and June than in other months of the year.
• Tornadoes can occur at any time of the day, but are most common in the late afternoon and early evening.
• The states with the highest average number of tornadoes are those in the Midwest. Texas, Oklahoma, and Florida also have a high number of tornadoes compared with other states.

2. Would you worry as much about the chance of tornadoes if you lived in Nevada as you would if you lived in Oklahoma or Kansas? Why?

   Based on the data examined in this activity, students should probably worry less about tornadoes if they lived in Nevada because the average number of tornadoes in that state is much lower than in Oklahoma or Kansas. Because the data for each state represent the average number of tornadoes each year over a period of many years, students can be fairly certain that Nevada has significantly fewer tornadoes.

3. In this activity, you studied patterns related to tornadoes.

   1. How did the data that you and your classmates analyzed provide information about patterns?

   The data used to calculate the averages were gathered over several years. Data gathered over a long period of time can be more informative, as data for a single year might reflect an average that is unusually high or unusually low. By using an average over many years, we can get a better idea of what the usual number of tornadoes during one year is.

   2. In what ways can it be helpful to recognize patterns in weather?

      Patterns can help us predict weather events. (In chapters 3 and 4 of this module, students will learn more about probability and how understanding the likelihood of an event helps people make decisions.)

   3. Can understanding and relying on patterns cause people to make the wrong decision?

      Yes. Sometimes people believe incorrectly that a pattern will always be the same. However, just because a natural event is not common in a certain area does not mean it cannot happen. For example, the map in Tornado Data Set 1 shows that Alaska has an average of 0 tornadoes per year. However, tornadoes have occurred in Alaska. If people believe that a tornado will not occur, they might not take the appropriate safety precautions if a tornado warning is issued.