A Continental United States Climatology of Precipitation Whiplash Using a New Event-Based Definition

Precipitation whiplash events have been increasingly studied in the scientific literature over the recent decade. However, no studies have considered the spatial coherence of grid points in their examination of whiplash events. Therefore, we developed an algorithm that defines spatially coherent precipitation whiplash events on the subseasonal-to-seasonal timescale between 1915 and 2020. We define precipitation whiplash events to occur when the 30-day Standardized Precipitation Index (SPI) moves from at or above +1 to at or below -1, or vice versa. Once grid points were identified as having undergone a whiplash occurrence, Kernel Density Estimation was used to create event polygons, taking into consideration the continuity of grid points. Events were then clustered into geographical regions using k-means clustering, allowing for the examination of their climatology and characteristics across the continental United States (CONUS). The developed definition is designed to be adaptable, allowing the generated databases to be utilized in future studies and significantly enhancing the understanding of precipitation whiplash events across CONUS. For more information and details regarding the event identification, please see the journal article: Puxley, B. L. and Martin, E. R. (2025) ‘A Continental United States Climatology of Precipitation Whiplash Using a New Event-Based Definition’ in the International Journal of Climatology. For access to any of the code used to generate these databases, please see the GitHub repository at INSERT LINK Any use of the databases in this Zenodo repository should cite the journal article and the Zenodo repository. Any use of the programs in the GitHub repository should cite the journal article Puxley, B. L. and Martin, E. R. (2025). Database Files independent_events_drought_to_pluvial.csv This file is a database of all drought-to-pluvial whiplash events used in the journal article for analysis. Events have been subsetted to events with an area greater than 175,000 km2, and the independence algorithm has been applied. independent_events_pluvial_to_drought.csv Same as above, but for pluvial-to-drought whiplash events. independent_events_droughts.csv Same as above, but for drought events only. independent_events_pluvials.csv Same as above, but for pluvial events only. all_events_drought_to_pluvial_no_areal_thresh.csv This file is a database of all potential drought-to-pluvial whiplash events. No areal threshold has been applied to these events, nor has the independence algorithm been applied. all_events_pluvial_to_drought_no_areal_thresh.csv This file is a database of all potential pluvial-to-drought whiplash events. No areal threshold has been applied to these events, nor has the independence algorithm been applied.