Signatures of fresh snowfall in the Dakotas
GOES-16 (GOES-East) Near-Infrared “Snow/Ice” (1.61 µm) images (above) depicted the signature of northwest-to-southeast oriented swaths of fresh snowfall (lighter gray shades) which had recently fallen on top of the aged snow pack across North Dakota on 17 March 2019. As discussed here, the surface of the preexisting snow cover had experienced rapid melting several days earlier, which increased its “water to ice crystal” ratio — making it appear darker, since water is a stronger absorber of radiation at the 1.61 µm wavelength.A similar (albeit broader and more continuous) northwest-southeast swath of fresh snowfall was seen across South Dakota (below).
The radar-derived 24 hour precipitation ending at 12 UTC on 17 March is shown below.