{"id":36122,"date":"2020-04-04T21:59:23","date_gmt":"2020-04-04T21:59:23","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=36122"},"modified":"2020-04-05T04:12:15","modified_gmt":"2020-04-05T04:12:15","slug":"signature-of-ice-accrual-across-the-upper-midwest","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/36122","title":{"rendered":"Signature of ice accrual across the Upper Midwest"},"content":{"rendered":"

\"GOES-16<\/a>

GOES-16 Mid-level Water Vapor (6.9 \u00b5m)<\/em> images, with hourly precipitation type plotted in red [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>GOES-16 (GOES-East)<\/em> Mid-level Water Vapor (6.9 \u00b5m<\/strong><\/a>) images (above)<\/strong> <\/em>showed a variety of precipitation types as a strong cold front moved slowly eastward across the Upper Midwest during the 02 April<\/strong><\/a> – 03 April 2020<\/strong><\/a> period — including thundersnow snow at Aberdeen, South Dakota and Oakes, North Dakota (at 18 UTC on 02 April<\/strong><\/a>) and freezing rain<\/strong><\/a> at a few sites in northern Iowa, the eastern Dakotas and western Minnesota.<\/p>\n

On the following day, in a comparison of GOES-16 “Red” Visible (0.64 \u00b5m<\/strong><\/a>) and Day Snow Fog<\/strong><\/a> Red-Green-Blue (RGB) images (below)<\/strong>,<\/em> the RGB images revealed darker red swaths across southeastern South Dakota, northwestern Iowa and western Minnesota (at the 1.61 \u00b5m wavelength, ice absorbs radiation more strongly than snow — which contributed to the darker appearance of those swaths). Note that these ice accrual swaths exhibited no signature in the Visible imagery.<\/p>\n

\"GOES-16<\/a>

GOES-16 “Red” Visible (0.64 \u00b5m)<\/em> and Day Snow Fog RGB images [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>Props to Carl Jones (NWS Grand Forks) for pointing this feature out.
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<\/p>\n
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Dark red swath extending through Minnesota is #ice<\/a> accretion from April 2-3 winter storm. Strong infrared absorption in the 1.61 component of the Day Snow-Fog RGB makes it darker compared to snow. Clearly shows where ice accretion occurred whereas visible cannot. #ndwx<\/a> #mnwx<\/a> pic.twitter.com\/L1rs7EskLa<\/a><\/p>\n

\u2014 Carl Jones (@northflwx) April 4, 2020<\/a><\/p><\/blockquote>\n