{"id":71703,"date":"2026-08-03T23:59:00","date_gmt":"2026-08-03T23:59:00","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=71703"},"modified":"2026-08-04T17:38:27","modified_gmt":"2026-08-04T17:38:27","slug":"river-valley-fog-in-the-upper-midwest-2","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/71703","title":{"rendered":"River valley fog in the Upper Midwest"},"content":{"rendered":"\n<figure class=\"wp-block-video aligncenter\"><video autoplay controls loop muted src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/08\/goeseast_abi_radc_true_color_night_s20260803050118_e20260803150118_f121.mp4\" playsinline><\/video><figcaption class=\"wp-element-caption\"><em>5-minute GOES-19 Nighttime Microphysics RGB + daytime True Color RGB images, from 0501-1501 UTC on 03 August<\/em><\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">5-minute CONUS Sector GOES-19 <em>(GOES-East)<\/em> <strong><a href=\"https:\/\/rammb2.cira.colostate.edu\/wp-content\/uploads\/2025\/07\/QuickGuide_GOESR_NtMicroRGB_Final_20191206_acc.pdf\">Nighttime Microphysics RGB<\/a><\/strong> + daytime True Color RGB images from the <strong><a href=\"https:\/\/geosphere.ssec.wisc.edu\/#playing:true;coordinate:-291865,-367270;zoom:1.4;num_frames:48;\">CSPP GeoSphere<\/a><\/strong> site <strong><em>(above)<\/em><\/strong> showed the formation of nocturnal river valley fog over parts of the Mississippi River and a few of its tributaries in Wisconsin, Minnesota, Iowa and Illinois on 03 August 2026. The river valley fog then dissipated within a few hours after sunrise.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">GOES-19 <strong><a href=\"https:\/\/cimss.ssec.wisc.edu\/goes\/OCLOFactSheetPDFs\/ABIQuickGuide_NightFogBTD.pdf\">Night Fog<\/a><\/strong> brightness temperature difference (BTD) + daytime Visible images <strong><em>(below)<\/em><\/strong> included hourly plots of Ceiling and Visibility &#8212; at some sites in the Wisconsin River valley, the visibility dropped to 1\/4 mile (or even to zero) at times.<\/p>\n\n\n\n<figure class=\"wp-block-video aligncenter\"><video autoplay controls loop muted src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/08\/260803_g19_irdiff_vis_cigvis_WI.mov\" playsinline><\/video><figcaption class=\"wp-element-caption\"><em>5-minute GOES-19 Night Fog BTD + daytime Visible images, from 0456-1501 UTC on 03 August<\/em><\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">A NOAA-21 VIIRS Day\/Night Band image at 0833 UTC (3:33 AM Central Time) revealed a faint signature of the river valley fog <strong><em>(below)<\/em><\/strong>, as illuminated by the Moon (which was in the Waning Gibbous phase, at 75% of Full).<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/08\/260803_0833utc_noaa21_viirs_dayNightBand_fog.png\"><img decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/08\/260803_0833utc_noaa21_viirs_dayNightBand_fog.png\" alt=\"\"\/><\/a><figcaption class=\"wp-element-caption\"><em>NOAA-21 (mislabeled by AWIPS as NPP) VIIRS Day\/Night Band image valid at 0833 UTC on 03 August [click to enlarge]<\/em><\/figcaption><\/figure>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>5-minute CONUS Sector GOES-19 (GOES-East) Nighttime Microphysics RGB + daytime True Color RGB images from the CSPP GeoSphere site (above) showed the formation of nocturnal river valley fog over parts of the Mississippi River and a few of its tributaries in Wisconsin, Minnesota, Iowa and Illinois on 03 August 2026. The river valley fog then [&hellip;]<\/p>\n","protected":false},"author":18,"featured_media":71704,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[13,159,131,45,48],"tags":[],"class_list":["post-71703","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-fog-detection","category-goes-19","category-noaa-21","category-redgreenblue-rgb-images","category-viirs"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/71703","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/users\/18"}],"replies":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/comments?post=71703"}],"version-history":[{"count":18,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/71703\/revisions"}],"predecessor-version":[{"id":71722,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/71703\/revisions\/71722"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/71704"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=71703"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=71703"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=71703"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}