Evaluating Precipitation Extremes from a Sparse Network: the NOAA U.S. Climate Reference Network

Changes in the frequency of extreme precipitation events impact the public safety, urban planning, and agriculture sectors. Differences between gauge shielding, minimum reported amounts, or temporal and spatial resolution between datasets make them harder to compare and evaluate for changes in extreme precipitation frequency. The United States Climate Reference Network (USCRN) provides reference triple-sensor sub-hourly precipitation records at 114 sites across the United States. This study evaluates the ability of a sparse reference network such as the USCRN to capture precipitation extremes with a one to five-year return interval over a ten-year period of record. Precipitation totals were calculated for each station based on rolling duration intervals. 89 of the stations were in areas with gridded NOAA Atlas 14 precipitation frequency data, to which the calculated precipitation totals were compared. Exceedance of the NOAA Atlas 14 precipitation frequency for each return interval and corresponding duration was noted. Throughout the NOAA Atlas 14 coverage area, a larger number of exceedances per year than predicted by the return interval were found for durations in the five-minute to one-day time frame. The network’s higher temporal (5-minute) and precipitation (0.2 mm) resolutions at the sub-hourly scale and better shielding increased the number of extreme precipitation events captured. The USCRN’s ability to capture extreme precipitation can be put to further use as a reference for studies evaluating changes in the frequency of extreme precipitation events.