Final answer:
Long-range forecasts often use numerical or statistical models to predict future events and can cover time spans longer than three weeks, allowing for probabilistic assessments of various outcomes such as weather conditions.
Step-by-step explanation:
The question pertains to the realm of long-range forecasts and their characteristics. When we talk about long-range forecasts, we refer to predictions that extend into the future beyond the typical range of short-term forecasts. In the context of the question, the correct option is 'd) Use numerical models.' These forecasts certainly make use of statistical models and mathematical functions to predict future events.
These models are powerful tools that include estimates of probability, and contrary to some of the other options, they can incorporate subjective judgments, cover periods that extend beyond three weeks, and they often rely heavily on complex statistics and probabilities to provide forecasts. An example can be seen in weather predictions, where meteorologists use statistical models and numerical simulations to forecast various possible outcomes for weather conditions and give a percentage chance of events like rain or snow happening.