Do Record Storm Events Produce Floods of the Same Magnitude?

A common basis for comparison among extreme storm events is the average recurrence interval (ARI), in years. Quantitative analysis of the rainfall time series aims to summarize the variables of interest (depth, duration, intensity, and time between storm events) and to assess the probability that storm events of various magnitudes will occur based on the rainfall record. Such analysis shows that the ARI of storm events and the subsequently generated floods downstream are not of the same magnitude. The floods generated by Hurricanes Fran and Alice were influenced by concentrated areal precipitation, particularly for Hurricane Fran. In the case of Hurricane Alice near Pandale, Texas, the storm event point precipitations were extreme, but much less concentration and contribution of areal precipitation occurred upstream of the Pecos River USGS streamflow gauging station near Shumla, Texas, than occurred for Hurricane Fran upstream of the Raleigh-Durham area streamflow gauging stations.