With upslope flow, moderate instability and strong flow aloft, supercell thunderstorms developed off the Palmer Divide and quickly moved east during the late afternoon/early evening of 29 June 2017. These storms produced numerous hail reports. Below is 5-min, 0.5 km visible imagery from GOES-16. Of note is the storm-split observed with the first area of convection, the southern storm making a sharp right turn. Considerable rotation was noted with this storm, though cloud bases were quite high. Convection to the west continued to initiate off of the higher terrain of the Palmer Divide thereafter.

Figure 1: 29 June 2017 GOES-16 0.64 um VIS in east-central Colorado. Full resolution: https://satelliteliaisonblog.files.wordpress.com/2017/06/20170629_co_vis4.gif
– Bill Line, NWS
“The GOES-16 data posted on this page are preliminary, non-operational data and are undergoing testing. Users bear all responsibility for inspecting the data prior to use and for the manner in which the data are utilized.”