Multiple severe warned supercells were visible today over southwest South Dakota. These were producing impressive updrafts as indicated by the green cooling cloud tops in the overshooting tops of the anvils. The direction of the cloud top flow in the anvils is clearly split along the line of development with both the speed, cooling cloud tops, and divergence providing a defined location for the center of each supercell. This location is particularly evident in the cooling cloud tops which provided a lead time of 5 to 15 minutes ahead of the divergence and potentially a couple of minutes before the strengthening of the radar reflectivity signal. I was also surprised by how much of a difference the parallax makes in this region. Overlaying these satellite images with radar, there was a noticeable difference in location of the supercells. This was visible in both the GOES-18 and GOES-19 images, with an offset of roughly 10 miles to the northeast and northwest respectively. With such a large gap, I am curious if this was accounted for when issuing severe thunderstorm and especially tornado warnings for the Cheyenne region that had little radar to go off of.

Figure 1: GOES-18 WMESO Octane speed, direction, cloud top divergence, and cloud top cooling.

Cloudius