Considerations for the use of radar-derived precipitation estimates in determining return intervals for extreme areal precipitation amounts

Areal precipitation amounts for the 2-, 5- and 10-year return period were computed by fitting an extreme value distribution to the areal radar, (and separately gauge), maxima from 5 years of available data. In one study area, the radar estimates tend to exceed those based on the gauge, whereas in a different region the gauge estimates tend to exceed those based on the radar. These results emphasize that a smaller radar ARF does not necessarily imply a lower radar mean areal precipitation.