![\"AWIPS](\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2017\/12\/171228_1602utc_goes16_4panel.png\")
<\/a>AWIPS screen capture of GOES-16 Cloud Top Phase product (top left), Near-Infrared “Snow\/ice” (1.61 \u00b5m, top right), Cloud Phase brightness temperature difference (8.5 – 11.2 \u00b5m, bottom left) and “Clean” Infrared Window (10.3 \u00b5m, bottom right) images [click to enlarge]<\/p><\/div>An AWIPS screen capture showing GOES-16 (GOES-East)<\/em> Cloud Top Phase, Near-Infrared “Snow\/ice” (1.61 \u00b5m<\/strong><\/a>), Cloud Phase brightness temperature difference (8.5 \u00b5m<\/strong><\/a> – 11.2 \u00b5m<\/strong><\/a>) and “Clean” Infrared Window (10.3 \u00b5m<\/strong><\/a>) images on 28 December 2017<\/strong><\/a> (above)<\/strong><\/em> was provided by Dan Baumgardt and Dave Schmidt (NWS La Crosse<\/strong><\/a>) — they were inquiring as to the why the 1.61 \u00b5m Snow\/Ice imagery appeared bright across southern Minnesota (suggesting cloud tops composed primarily of supercooled water droplets), where light snow was being reported at a number of locations. Note that the Cloud Top Phase product also indicated that much of the stratus cloud deck over that same region was either Supercooled (light green)<\/em> or Mixed (dark green)<\/em>.<\/p>\n An animation of GOES-16 Snow\/Ice (1.61 \u00b5m<\/strong><\/a>) imagery (below)<\/strong><\/em> showed that the high reflectance (brighter white)<\/em> signature of the lower-altitude stratiform cloud deck persisted across southern Minnesota into western Wisconsin and northern Iowa during the daylight hours, along with widespread surface reports of light snow. In contrast, higher-altitude clouds composed predominantly or entirely of ice crystals exhibited a darker gray appearance (since ice crystals, as well as surface snow cover and frozen lakes\/rivers, are strong absorbers of radiation at the 1.61 \u00b5m wavelength).<\/p>\n GOES-16 Near-Infrared “Snow\/Ice” (1.61 \u00b5m) images, with hourly surface-observed precipitation type plotted in yellow [click to play MP4 animation]<\/p><\/div>In the corresponding GOES-16 “Clean” Infrared Window (10.3 \u00b5m<\/strong><\/em><\/a>) animation (below),<\/strong><\/em> much of the aforementioned lower-altitude stratiform cloud layer exhibited cloud-top infrared brightness temperatures in the -10 to -20 \u00baC range across far southern Minnesota into northern Iowa, with colder -20 to -30 \u00baC values seen in the more northern and eastern portion of the stratus cloud.<\/p>\n GOES-16 “Clean” Infrared Window (10.3 \u00b5m) images, with hourly surface-observed precipitation type plotted in yellow [click to play MP4 animation]<\/p><\/div>Plots of rawinsonde data (at 12 UTC on 28 December) from Aberdeen, South Dakota and Chanhassen, Minnesota (below)<\/strong><\/em> showed that the temperature profiles within the low-altitude cloud layers were close to isothermal, with air temperatures generally in the -16 to -22 \u00baC range.<\/p>\n<\/a><\/a>