The effect of snow cover on boundary layer cloud development

March 15th, 2020 |

GOES-16 Snow/Cloud Discrimination RGB images [click to play animation]

GOES-16 Snow/Cloud Discrimination RGB images, with hourly plots of surface wind barbs (knots) [click to play animation]

GOES-16 (GOES-East) “Snow/Cloud Discrimination” Red-Green-Blue (RGB) images (above) revealed a west-to-east oriented band of fresh snow cover (1-4 inches, shades of red) across central Illinois on 15 March 2020. With a low-level northeasterly flow of cold air across the region, boundary layer cumulus clouds began to develop as solar heating warmed the surface — but this cloud development was suppressed over deeper portions of the snow cover. These RGB images use “Red” Visible (0.64 µm) data as the Red component, and Near-Infrared “Snow/Ice” (1.61 µm) data as the Green and Blue components; bare ground appears as shades of cyan, with supercooled water droplet clouds appearing as brighter shades of white.

A sequence of VIIRS Snow/Cloud Discrimination RGB images from NOAA-20 and Suomi NPP (below) showed a closer look at the band of snow cover and its effect on modulating the afternoon development of cumulus clouds.

VIIRS Snow/Cloud Discrimination RGB images from NOAA-20 and Suomi NPP [click to enlarge]

VIIRS Snow/Cloud Discrimination RGB images from NOAA-20 and Suomi NPP [click to enlarge]

A 30-meter resolution Landsat-8 False Color RGB image viewed using RealEarth (below) provided a detailed view of the band of snow cover (shades of cyan) at 1622 UTC.

Landsat-8 False Color RGB image, with and without labels [click to enlarge]

Landsat-8 False Color RGB image, with and without labels [click to enlarge]

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