Precipitation trends in North and South Carolina, USA

Study regionNorth and South Carolina, USA.Study focusIntense precipitation poses risks to life and property. Its frequency can change in response to global-scale drivers, but its spatial expression can vary seasonally and regionally, and be dependent on how it is measured and what analysis period is used. We investigate forty-four historical stations from the U.S. Historical Climatology Network (USHCN) across North and South Carolina to determine trends in the pluviometric regime defined by the Expert Team on Climate Change Detection and Indices (ETCCDI).New hydrological insights for the regionMost of the stations in this area do not display consistent, statistically significant trends across the suite of ETCCDI measures of precipitation amount, frequency, and intensity. In addition, the direction, spatial patterns and cross seasonal results are not consistent for the small number of stations that do show a trend in annual or seasonal precipitation totals. A third of stations have a statistically significant increasing trend in the annual number of light rain days; these generally match those with a statistically significant trend in wet days. Relatively few stations, typically around 10 per cent, have statistically significant trends in precipitation intensity measures. Notable exceptions include 2- and 5-day fall maximum precipitation values. Our findings contribute to a broader literature regarding trends in the southeastern United States (SEUS) and have significant relevance in adaptation planning that seeks to understand the relative contribution of multiple causes of natural hazards.