Hydroclimatic extremes, such as floods and droughts, challenge water resources management, and the severity, duration, and frequency of these events are expected to increase with future climate change. These “weather whiplash” events have historically been characterized on an annual or decadal basis (i.e., shifts from drought to wet years); however, there have been recent calls to understand sub-annual weather whiplash events and their impacts on both hydrology and water quality. Here, we analyzed data from 86 USGS gages across Arkansas (1950-2024) to detect sub-seasonal whiplash events, defined as transitions from drought to flood conditions within 30 days. We classified events as moderate (e.g., shifts from 10th percentile of flow to 90th percentile) and severe (e.g., shifts from 5th percentile of flow to 95th percentile) and also characterized their magnitude and transition speed. We also adjusted for the number of active gages each year. Over a 70-year period, the severity of whiplash events declined steadily from 20% of events in the 1950s to a historic minimum of 6% in the 2010s. However, Arkansas experienced a statewide, unprecedented increase in severity in the 2020’s. The state recorded 26 weather whiplash events in 2024, representing a 500-year return interval (σ=2.9). Moreover, 31% of 2024 events were categorized as severe, a 5x increase compared to the 2010s. The shift in the 2020s coincided with the warmest 5-year period on record in Arkansas, and 2024 was the second hottest year in the 74-year record. The contrast between long-term decreasing severity and the 2024 surge suggests that managing water resources for gradual change may not be sufficient under future climate conditions. Looking to the future, effective water resources management requires infrastructure and planning frameworks capable of handling extreme sub-seasonal variability that may significantly exceed historical precedent, particularly as warming patterns continue.