Why can a butterfly flap its wings in Brazil and cause a tornado in Texas a month later? ?

This is a metaphor for the butterfly effect. The butterfly effect was first put forward by meteorologists. By chance, they found that when a numerical value used to forecast the weather changes slightly, there is no difference in the short-term weather forecast, while the result of the long-term weather forecast is very different from that before the change. That is to say, in a system, a small change in a certain value will lead to unpredictable changes in the results after a long time, which also proves that long-term weather forecasting is impossible. The proponent of the butterfly effect quipped that a butterfly flapping its wings in Brazil (a slight disturbance of the weather system) will trigger a tornado in Texas in a month (for a long time) (the consequences are unpredictable).