The accuracy and usefulness of any forecasting tool—numerical model data, satellite imagery, or other data sources—depends on various factors that a forecaster needs to evaluate for each situation. The same is true for radar data. The radar processor operates on a number of assumptions that may not be met in many circumstances. In fact, it is possible for images to contain false readings.

A savvy forecaster needs to discriminate when radar data are valuable and when they contain erroneous data by keeping in mind the issues and assumptions discussed in this chapter.