Slow-Moving Storms Raise Flash-Flood Risk From Appalachians Through Texas and the Desert Southwest

Overview

• Forecasters report storms producing extreme rainfall rates of 1.5–4 inches per hour and localized multi-inch totals, with some areas seeing 3–6+ inches that are already causing or likely to cause flash flooding.
• The highest flood threats extend from the southern Appalachians and southern Mid‑Atlantic through central and northern Texas, the Upper Texas Coast into southwest Louisiana, western Texas highlands, and parts of the Desert Southwest.
• NWS analyses point to very high precipitable water, tall 'skinny' CAPE profiles, mid‑level vortices and stationary fronts combined with weak steering as the reason storms are efficiently producing heavy warm‑rain totals through backbuilding and training.
• The Storm Prediction Center flagged localized strong downbursts and dry‑microburst potential in parts of Arizona and Montana but judged a formal severe thunderstorm watch unlikely, while the WPC continued issuing mesoscale precipitation discussions for multiple regions.
• Urban areas, low‑lying canyons, arroyos and mountain upslope zones are most vulnerable; residents should follow local NWS forecasts, avoid flooded roads, and monitor short‑range updates into the evening for shifting flash‑flood risk.