The current version of HEC-SSP allows the user to infer probability distributions for nearly any type of data that can be stored in DSS format. Specifically, up to 19 different analytical distributions can be parameterized using three different fitting methods. Common hydrologic analyses attempt to estimate flow, stage, or precipitation depth (amongst other variables) for a given annual exceedance probability (AEP) or estimate the probability that a given flow, stage, or precipitation depth will exceed a particular value. In order to answer these questions, fully parameterized analytical probability distributions are often used. Additionally, depending upon the application, different sources of uncertainty may result in varying estimates of the necessary information. These sources of uncertainty can include (but are not limited to) small sample sizes, measurement uncertainty, choice of probability distribution, and/or choice of parameterization (fitting method). The Distribution Fitting Analysis is a tool that can be utilized to answer the previously noted questions as well as multiple sources of uncertainty.
Examples of this type of analysis can be found here:
