Shown is the progression of developing tower to severe storm with strong storm top divergence on the thunderstorm over the Colorado/New Mexico border. From around 1940Z to 1955Z  the Octane Speed showed the development of storm top divergence while both versions of ProbSevere increased in severe probabilities. The Octane Speed product then showed the upshear side of the storm become “stationary” as the storm top divergence strengthened even further after 20Z, lining up with ProbSevere V3’s signal that the storm had become severe.

-Joaq