Signature of ice accrual across South Dakota and Minnesota

By Scott Bachmeier • 1 January 2019

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

GOES-16 (GOES-East) Near-Infrared “Snow/Ice” (1.61 µm) images (above) revealed a darker swath — oriented southwest to northeast, from central South Dakota to central Minnesota — highlighting areas which received an accrual of ice (from freezing rain/drizzle) during a 30 December – 31 December 2018 mixed precipitation event (surface analyses). Light to moderate Freezing Rain was reported at Watertown SD (KATY) for 3.5 consecutive hours (plot | text).

As seen in a plot of ABI Spectral Response Functions (below), snow and ice are efficient absorbers of radiation (and therefore exhibit a low relectance) at the 1.61 µm wavelength, making them appear darker on the Snow/Ice imagery — and since ice absorbs more strongly than snow, it appears as the darkest shades of gray/black. Strong northerly winds in the wake of the precipitation event then swept the residual ice-crusted snow cover clear of any new snowfall.

Plots of Spectral Response Function for ABI Bands 1-5 [click to enlarge]

A higher spatial resolution view using VIIRS Near-Infrared “Snow/Ice” (1.61 µm) images from NOAA-20 (at 1839 UTC) and Suomi NPP (at 1931 UTC) is shown below. The darkest areas on the Snow/Ice images appeared to be over the southern/western portion of Deuel County in South Dakota and much of Chippewa County in Minnesota.

VIIRS Near-Infrared “Snow/Ice” (1.61 µm) images from NOAA-20 (at 1839 UTC) and Suomi NPP (at 1931 UTC) [click to enlarge]

Categories: GOES-16, NOAA-20, Suomi NPP, VIIRS, Winter weather

CIMSS Satellite Blog

CIMSS Satellite Blog

Signature of ice accrual across South Dakota and Minnesota