Ralph et al. (2017) defined ARs as narrow corridors of strong horizontal water vapor transport. However, most studies focus on 24–72 hr events. Dettinger (2013) noted “AR families”—repeated landfalls over 7–10 days—but did not define thresholds for a single continuous torrent. Paleoflood evidence from the Sacramento Valley (Ingram & Malamud-Roam, 2013) indicates “megafloods” with 45-day durations in the 9th, 14th, and 17th centuries, likely caused by persistent PTs under specific sea surface temperature (SST) anomalies.
Why coin a new term? Existing classifications (AR 1–5) capture daily intensity but not multi-week endurance. The 1861–1862 Great Flood of California, often called an “atmospheric river” event, actually represented a Pacific Torrent. More recently, December 2023–January 2024 saw a near-PT that caused >$11B in damages. Recognizing PTs as a distinct hazard class improves long-range forecasting and infrastructure design. the pacific torrent
IVT during PT events has increased by 18% per decade since 1980 (p<0.01), consistent with Clausius–Clapeyron scaling. The frequency of PT events (≥14 days) has risen from 0.2 per decade (1950–1980) to 1.5 per decade (2000–2024). This suggests a doubling by 2050 under RCP 8.5. Ralph et al
The metaphorical Pacific Torrent is not reversible. Attempts to dam it (tariffs, tech decoupling) create backwater effects—e.g., US tariffs on Chinese EVs (2024) redirected the torrent through Vietnam and Mexico. Just as atmospheric PTs find a new corridor when the jet stream shifts, capital and culture will circumvent barriers. Policy should focus on “spillway design”—managed competition rather than futile blockade. tech decoupling) create backwater effects—e.g.