Unpredictability in a deterministic model of the weather. The blue line depicts the relative humidity predicted by the nonlinear model for a given set of conditions. The red line shows the humidity under exactly the same conditions except that the initial temperature was increased by 0.000001°C. The change had no effect on the prediction for about 1300 minutes. Thereafter, the two cases differed markedly, showing that the system could respond to and modify its behavior as a result of changes that would be entirely insignificant under the assumption of a linear model.