Blowing snow across the Upper Midwest

January 24th, 2019 |

GOES-16

GOES-16 “Red” Visible (0.64 µm) and Near-Infrared “Snow/Ice” (1.61 µm) images [click to play MP4 animation]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Near-Infrared (1.61 µm) images (above) displayed a long plume of horizontal convective roll (HCR) clouds across parts of the Upper Midwest on 24 January 2019. These HCR cloud features formed in the presence of strong northerly/northwesterly boundary layer winds in the wake of a cold frontal passage (surface analyses), and often highlight areas where significant blowing snow and ground blizzard conditions are likely occurring.

Animations of GOES-16 Visible and Snow/Ice images with plots of surface winds and weather type are shown below. ASOS sites report Haze (“H”) when the surface visibility — in this case, reduced by blowing snow — is less than 7 miles but greater than or equal to 4 miles. Some sites in Minnesota and Iowa reported a visibility between 0.5 and 2.0 miles at times (animation).

GOES-16 "Red" Visible (0.64 µm) images, with hourly plots of surface wind barbs and weather type [click to play MP4 animation]

GOES-16 “Red” Visible (0.64 µm) images, with hourly plots of surface wind barbs and weather type [click to play MP4 animation]

GOES-16 Near-Infrared "Snow/Ice" (1.61 µm) images, with hourly plots of surface wind barbs and weather type [click to play MP4 animation]

GOES-16 Near-Infrared “Snow/Ice” (1.61 µm) images, with hourly plots of surface wind barbs and weather type [click to play MP4 animation]

The signature of the HCR clouds on GOES-16 Day Cloud Phase Distinction Red-Green-Blue (RGB) images from the AOS site (below) was one that more closely resembled ice crystal clouds (light pink hues) than supercooled water droplet clouds (brighter shades of white) — suggesting a high concentration of blowing snow lofted within the boundary layer by the HRC circulations. Snow cover appears as shades of green in the RGB images.

GOES-16 Day Cloud Phase Distinction RGB images [click to play animation | MP4]

GOES-16 Day Cloud Phase Distinction RGB images [click to play animation | MP4]