{"id":71533,"date":"2026-07-27T23:59:00","date_gmt":"2026-07-27T23:59:00","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=71533"},"modified":"2026-07-29T04:01:37","modified_gmt":"2026-07-29T04:01:37","slug":"severe-thunderstorms-produce-tornadoes-large-hail-and-damaging-winds-from-upper-michigan-to-the-chicago-area","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/71533","title":{"rendered":"Severe thunderstorms produce tornadoes, large hail and damaging winds from northern Wisconsin to the Chicago area"},"content":{"rendered":"\n<figure class=\"wp-block-video aligncenter\"><video autoplay controls loop muted src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/07\/G19_VIS_IR_WI_IL_SVR_27JUL2026_loop_GOES-19_2026208_132028_2026208_204825.mp4\" playsinline><\/video><figcaption class=\"wp-element-caption\"><em>1-minute GOES-19 Visible and Infrared Window images with time-matched plots of SPC Storm Reports (T=Tornado, H300=Hail 3.00&#8243; in diameter, W74=Wind gust 74 mph, W=Wind damage), from 1320-2048 UTC on 27 July [best viewed as an <a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/07\/G19_VIS_IR_WI_IL_SVR_27JUL2026_loop_GOES-19_2026208_132028_2026208_204825.gif\"><strong>animated GIF<\/strong><\/a>]<\/em><\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">1-minute Mesoscale Domain Sector GOES-19 <em>(GOES-East)<\/em> Visible and Infrared Window images <strong><em>(above)<\/em><\/strong> included time-matched plots of <strong><a href=\"https:\/\/www.spc.noaa.gov\/climo\/reports\/260727_rpts.html\">SPC Storm Reports<\/a><\/strong> &#8212; most notably the <strong><a href=\"https:\/\/www.weather.gov\/grb\/07272026_SevereStorms\">EF3-rated<\/a><\/strong> tornado that moved through the Appleton\/Menasha area in northeastern Wisconsin, beginning around <strong><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/07\/G19_VIS_IR_WI_IL_SVR_27JUL2026_B213_2026208_165625_0002PANELS_FRAME00217.GIF\">1656 UTC<\/a><\/strong> &#8212; produced by clusters of thunderstorms on <strong><a href=\"https:\/\/www.wpc.ncep.noaa.gov\/dailywxmap\/index_20260727.html\">27 July 2026<\/a><\/strong>. Very large hail also occurred in Wisconsin with these storms, including a few reports of 3.00 inches in diameter (and one report of 4.50 inches in diameter, which did not get plotted). Separate thunderstorms also produced large hail, damaging winds and a few tornadoes in the Chicago area.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">1-minute GOES-19 Visible and Infrared Window images with an overlay of surface fronts <strong><em>(below)<\/em><\/strong> depicted the presence of a surface trough \/ developing warm front across eastern Wisconsin &#8212; the severe thunderstorms were moving southward near or just east of that surface boundary.<\/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\/07\/260727_g19_vis_ir_fronts_WI_IL.mov\" playsinline><\/video><figcaption class=\"wp-element-caption\"><em>1-minute GOES-19 Visible and Infrared Window images with an overlay of surface fronts, from 1401-2200 UTC on 27 July<\/em><\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">A closer look centered near Appleton, METAR identifier KATW <strong><em>(below)<\/em><\/strong> showed very high dew points across that area, with KATW reporting a dew point of 81 F at 1545 UTC (<strong><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/07\/260727_KATW_SFCMG.GIF\">surface report plot<\/a><\/strong>), about an hour before the tornado. As the parent thunderstorm was approaching from the north, pulses of overshooting tops exhibited infrared brightness temperatures as cold as -75 to -78 C (brighter white pixels embedded within dark black regions).<\/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\/07\/260727_g19_vis_ir_metar_zoom.mov\" playsinline><\/video><figcaption class=\"wp-element-caption\"><em>1-minute GOES-19 Visible and Infrared Window images with plots of METAR surface reports, from 1401-1900 UTC on 27 July <\/em><\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">According to a plot of rawinsonde data from Green Bay <strong><em>(below)<\/em><\/strong>, infrared brightness temperatures of -75 to -78 C represented a significant overshoot of the Most Unstable (MU) air parcel&#8217;s Equilibrium Level (EL). The sounding also portrayed a very unstable atmosphere having a CAPE value of 4770 J\/kg and a Lifted Index of -12 C.<\/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\/07\/260727_1200utc_kgrb_raob.png\"><img decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/07\/260727_1200utc_kgrb_raob.png\" alt=\"\"\/><\/a><figcaption class=\"wp-element-caption\"><em>Plot of rawinsonde data from Green Bay, Wisconsin at 1200 UTC on 27 July [click to enlarge]<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">Also of note was the Total Precipitable Water (PW) value of 2.12 inches &#8212; according to the <strong><a href=\"https:\/\/www.spc.noaa.gov\/exper\/soundingclimov2\/\">SPC Sounding Climatology<\/a><\/strong> site, this was a record high PW value for all 27 July 1200 UTC soundings at Green Bay <strong><em>(below)<\/em><\/strong>.<\/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\/07\/260727_1200utc_kgrb_tpw_climatology.png\"><img decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/07\/260727_1200utc_kgrb_tpw_climatology.png\" alt=\"\"\/><\/a><figcaption class=\"wp-element-caption\"><em>Climatology of Total Precipitable Water (PW) for all 1200 UTC soundings at Green Bay, with the 27 July value highlighted [click to enlarge]<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n<figure class=\"wp-block-embed is-type-rich is-provider-bluesky-social wp-block-embed-bluesky-social\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"bluesky-embed\" data-bluesky-uri=\"at:\/\/did:plc:77dhr6najvsvgwlk3glccqh2\/app.bsky.feed.post\/3mrpnjfpzj22h\" data-bluesky-cid=\"bafyreic25dmf2pkoahnedslxegcabatmimyni22yxu4z3uy2apog25lmn4\"><p lang=\"en\">It is uncommon to see strong tornadoes in the morning in Wisconsin. Looking back from 1950 through April 30 of this year, the prime time for strong tornadoes in Wisconsin is between 2 and 7 pm (CST). Yesterday&#39;s tornado began at 10:56 am CST, making it just the 10th to start during that hour.<\/p>&mdash; <a href=\"https:\/\/bsky.app\/profile\/did:plc:77dhr6najvsvgwlk3glccqh2?ref_src=embed\">Wisconet (@wisconet.bsky.social)<\/a> <a href=\"https:\/\/bsky.app\/profile\/did:plc:77dhr6najvsvgwlk3glccqh2\/post\/3mrpnjfpzj22h?ref_src=embed\">2026-07-28T14:44:03.051Z<\/a><\/blockquote><script async src=\"https:\/\/embed.bsky.app\/static\/embed.js\" charset=\"utf-8\"><\/script>\n<\/div><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>1-minute Mesoscale Domain Sector GOES-19 (GOES-East) Visible and Infrared Window images (above) included time-matched plots of SPC Storm Reports &#8212; most notably the EF3-rated tornado that moved through the Appleton\/Menasha area in northeastern Wisconsin, beginning around 1656 UTC &#8212; produced by clusters of thunderstorms on 27 July 2026. Very large hail also occurred in Wisconsin [&hellip;]<\/p>\n","protected":false},"author":18,"featured_media":71534,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[159,3],"tags":[],"class_list":["post-71533","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-goes-19","category-severe-convection"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/71533","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=71533"}],"version-history":[{"count":29,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/71533\/revisions"}],"predecessor-version":[{"id":71563,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/71533\/revisions\/71563"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/71534"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=71533"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=71533"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=71533"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}