Overview
- A cold-pool-driven mesoscale convective system (MCS) that grew from merging supercells produced measured gusts above 90 mph near Colby, Kansas and caused reported damage late Sunday evening.
- Real-time analyses show the MCS has a strong rear-inflow jet and book-end vortices that can concentrate damaging straight-line winds in a narrow swath and sustain very large hail where strong updrafts persist.
- The Storm Prediction Center is coordinating downstream Severe Thunderstorm Watches for northern Oklahoma, the Oklahoma and Texas panhandles, western Missouri, and Arkansas as the complex moves southeast.
- The Weather Prediction Center has placed parts of southeastern Nebraska, northeastern Kansas, and northwestern Missouri in a Moderate Risk for excessive rainfall because repeated storms could cause scattered to widespread flash flooding through June 23.
- Forecast uncertainty centers on whether nocturnal cooling will weaken the complex or whether it will maintain organization; residents in the path should expect strong, fast-moving gusts, hail, and localized flash flooding and should follow local NWS products and warnings.