Trends in short-duration precipitation extremes in the U.S.

The National Oceanic and Atmospheric Administration (NOAA) operates sub-daily in situ observing networks measuring precipitation on timescales that range from 5-minute to hourly. These include the National Weather Service (NWS) Fischer-Porter (F&P) network and the U.S. Climate Reference Network. The F&P network has operated since the mid-20th century, providing one of the longest records of hourly and 15-minute precipitation observations in the U.S., while the USCRN provides observations at timescales as short as 5-minute intervals. Observations from these and other NOAA networks are augmented by an even greater number of precipitation gauges operated by dozens of other federal and state partners. These data are acquired via the NWS Hydrometeorological Automated Data System (HADS) and archived at NOAAs National Centers for Environmental Information (NCEI). In total more than 10,000 stations provided hourly and sub-hourly observations in the U.S. in 2021, with many of these having lengthy records of precipitation on timescales from 5 minutes to hourly. The high spatial density and high sampling frequency of these gauges, brought together in an integrated dataset, has improved the ability to assess trends and variability of short-duration precipitation extremes across the country. An overview of this high resolution dataset is provided along with its use in the analysis of recent extreme precipitation events. Perspectives on changes in the frequency and intensity of sub-hourly precipitation in the U.S. are also provided.