Plains Supercells Organize Into Clusters as Urban Flood Risk Rises

Overview

• Severe Thunderstorm Watch 98, issued Thursday evening by the Storm Prediction Center, covered much of Kansas, northwest Missouri and southeast Nebraska with risks that included 2.5-inch hail, 60–75 mph wind gusts and a brief tornado threat.
• Across northern Kansas later Thursday, forecasters observed a shift from discrete supercells to larger convective clusters, which raised the risk for damaging straight-line winds as storms moved along and north of the I-70 corridor.
• The Weather Prediction Center late Thursday warned that storms near the Kansas–Nebraska border would train and merge, producing 1.5–2.5 inches of rain per hour and localized 2–4 inch totals that could trigger urban flash flooding from northeast Kansas into west‑central Missouri.
• In Houston on Friday evening, slow-moving storms along colliding outflow boundaries produced 2+ inch per hour rain rates with isolated 3–4 inch totals, which can quickly overwhelm street drainage and bayous in dense neighborhoods.
• Early Saturday, elevated thunderstorms expanded from northeastern Kansas into southern and southeastern Nebraska with a strengthening low‑level jet and 1.0–1.3 inch precipitable water, setting up brief training and 1–2 inch per hour downpours where recent rain has lowered flood thresholds.