Weather forecasts are based on a weather forecaster's judgment on which one of a number of scenarios is likely to happen. each scenario, in turn, is based on a prediction on what may happen in the future given conditions that almost always change in unexpected ways. thus, it is difficult to trust weather forecasts.
which of the following statements best expresses the main conclusion of the above argument?

1. conditions almost always change in unexpected ways.

2. weather forecasts are difficult to trust

3. weather forecasts are based on a number of potential scenarios.