Slow‑Moving Storms Produce Flash Flooding Threat Across Large Swath of Eastern and Central U.S.

Overview

• Sunday morning reports show significant flash flooding in the Southern Appalachians with localized 5–7 inch totals and additional cores producing 2–4 inches, prompting ongoing WPC mesoscale products and local flood warnings.
• WPC issued multiple Mesoscale Precipitation Discussions for hotspots including the Ohio Valley, Tennessee Valley, Florida Panhandle, Texas Hill Country, and New Mexico because slow cell motions and repeated storms can yield rates of 1–3 inches per hour and spotty 4–5+ inch amounts.
• Forecasters say the heavy rain is driven by very high precipitable water, strong low‑level moisture transport and instability that favors efficient, training convection capable of overwhelming urban drainage, small streams, burn scars and steep Appalachian slopes.
• SPC highlighted a concurrent, localized severe threat for damaging gusts and a few tornadoes in parts of the Ohio and Tennessee Valleys and said watch issuance was being considered but remained uncertain in some areas.
• Operational models disagree on exact storm placement so WFOs and RFCs are maintaining close coordination with WPC and SPC; residents in affected metro areas and flood‑prone terrain should follow local warnings and avoid flooded roads.