Lake Michigan mesovortex1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Day Cloud Phase Discrimination RGB images (above) showed the development of a mesovortex over southern Lake Michigan on 12 February 2021. The surface flow supporting the mesovortex formation was well-depicted by hourly RAP40 model output. Note that there was a lack of GOES-16 Visible (Band 2) Derived Motion Winds created for this feature — this was likely due to high clouds drifting over the area, making it difficult for the algorithm to properly identify and track surface or near-surface cloud elements. In the western portion of the lake, a ribbon of ice was evident in the nearshore waters of Wisconsin and Illinois.
The GOES-16 Day Cloud Phase Discrimination RGB images indicated that convective cloud elements near the vortex center were becoming glaciated (as highlighted by brighter shades of green) — and light snow reduced the surface visibility to 2.5 miles at Holland, Michigan (KBIV) as the vortex moved inland. A toggle between GOES-16 Visible and Day Cloud Phase Discrimination RGB images at 1800 UTC is shown below.