Power plant plume over southern Wisconsin
1-minute GOES-19 Nighttime Microphysics RGB + daytime True Color RGB images, from 0901-1900 UTC on 21 February [click to play MP4 animation]
1-minute Mesoscale Domain Sector GOES-19 (GOES-East) Nighttime Microphysics RGB + daytime True Color RGB images from the CSPP GeoSphere site (above) showed the formation of a long power plant plume (nighttime shades of red) embedded within a supercooled water droplet cloud layer (nighttime shades of yellow) that grew and moved southeastward across southern Wisconsin on 21 February 2026. The power plant plume had the effect of eroding the supercooled water droplet cloud layer — via glaciation, initiated by the power plant emission of particles that acted as efficient ice nuclei — which then caused snow to fall from the cloud (leaving holes and thin cloud segments that were very apparent in True Color RGB images).
A toggle between the GOES-19 Night Fog Brightness Temperature Difference (BTD) image and Cloud Top Phase derived product at 1200 UTC (below) confirmed that the cloud layer across southern Wisconsin was composed of supercooled water droplets (lime green enhancement).
GOES-19 Night Fog BTD and Cloud Top Phase derived product at UTC on 21 February [click to enlarge]
1-minute GOES-19 Night Fog BTD + daytime Visible images (below) suggested that the Columbia Energy Center in northwest Columbia County was the source of the power plant plume.
1-minute GOES-19 Night Fog BTD + daytime Visible images, from 0801-1819 UTC on 21 February [click to play MP4 animation]