 As the upper-level trough rapidly intensified, 500mb winds increased to 70–80 mph (110–130 km/h) and 850mb winds topped 70 mph (110 km/h) across the High risk area.The combination of speed shear and adequate directional shear (noted by curved low-level hodographs) led to 0–3 km storm relative helicities of 300–500 m2/s2, favorable for rotating thunderstorms.A capping inversion, qualified by cold and dry air aloft, initially prevented the formation of thunderstorms and instead allowed substantial surface heating.