By 2200z, a strong cluster of storms was ongoing in northwestern Minnesota ENE of the KMVX RDA while moving northeast. Below are a set of 4 figures showing the divergence at the cloud top of the ongoing cell, with a cyan circle outlining the updraft area.
Here is a comparison of the Optical Flow Winds divergence versus storm top divergence provided by traditional means:
OFW – STD
>100 – ~115 kt
~80 – ~105 kt
>100 – ~150 kt
> 100 – ~130kt
–aerobeaver