A Comparison of the Optical Flow Winds “Divergence” Product and KMVX Radar Storm-Top Divergence

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:


>100 – ~115 kt

~80 – ~105 kt

>100 – ~150 kt

> 100 – ~130kt

While the divergence output wasn’t as high, it seemed to behave consistently below the traditional storm top divergence which means it could be adjusted up in the forecaster’s head. I’d love to see a little more discerning from the color curve for divergence, as it shows little difference, and when it goes over 100, it is all red. Also, it would be nice to see the exact unit that it uses, as it seems assumed that it’s kts.