*3.1. Characterization of Annual Maxima*

Radar precipitation estimates provide new possibilities to investigate the climatology of extreme rainfall at high spatial resolutions and over large areas [7]. Louisiana is considered one of the wettest of the contiguous 48 US states with extreme events that are generated by various rainfall mechanisms. Extreme events in the Southeastern US are typically generated from different synoptic weather patterns, for example, tropical storms, fronts, and convective airmass thunderstorms [27]. Figure 1a shows the Mean Annual Maxima (MAM) rainfall depth for each pixel in the domain of the study area. Most of the maxima are in the range between 20 mm and 100 mm with a significant spatial increase towards the gulf coastal zone. Figure 1b depicts the spatial distribution of average month of occurrence for annual maximum rainfall and shows dominance of the summer season (June—July—August) throughout most of the state. These results agree with Maddox et al. [35] who concluded that most of the extreme events that cause flash floods are of convective nature with the predominance of events in the warm season (April-September). The diurnal distribution of the annual maxima is illustrated by the average 6-h of annual maxima occurrence (Figure 1c). Most of the annual maxima occurred between 18:00 UTC and 00:00 UTC, while fewer number of events occurred in the two intervals (00:00 UTC–06:00 UTC) and (12:00 UTC–18:00 UTC).
