FloodZoneMap.org

Severe thunderstorms developed over central Oklahoma along and ahead of a dry line during the afternoon of the 19th, as an upper level disturbance approached the Southern Plains. These thunderstorms moved northeast off the dry line and across portions of northwestern Arkansas during the evening hours. The atmosphere east of the dry line across northwestern Arkansas became very unstable during the afternoon and evening, and this instability combined with strong deep-layer and low-level wind shear