In recent decades, there has been increased attention on drought and the aridification of parts of the western contiguous United States (CONUS) (Bishop et al., 2021). The continually updated U.S. billion-dollar weather and climate disasters data set (NOAA-NCEI, 2021;Smith & Katz, 2013) reports that droughts and heatwaves represent nearly a quarter of all long-term weather and climate disaster costs exceeding 1 billion dollars per event, and that vulnerability to these drought events has increased from 1980 to 2020. Droughts have wide ranging impacts on agriculture, water utilities, power generation, recreation and tourism, aquatic species, forest resources, public health and other sectors (Wlostowski et al., 2022). National scale streamflow studies have found increasing occurrences of streams with no flow in the southern and western CONUS (Zipper et al., 2021), decreases in the magnitude of the lowest flows in the southeastern and parts of western CONUS, and increases in the lowest flows in the northeastern and midwestern CONUS (Dethier et al., 2020;Dudley et al., 2020). Runoff reductions in future years for western regions of the CONUS are likely a result of projected precipitation decreases and temperature increases (McCabe & Wolock, 2021b), especially where the temperature increases lead to reductions in seasonal snowpack and water yield (Barnhart et al., 2016;McCabe et al., 2017;Milly & Dunne, 2020). These studies highlight the need for increased understanding of streamflow drought variability, trends, climatic, landscape and anthropogenic drivers.