{"id":71442,"date":"2026-07-23T15:59:00","date_gmt":"2026-07-23T15:59:00","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=71442"},"modified":"2026-07-24T23:44:58","modified_gmt":"2026-07-24T23:44:58","slug":"large-area-of-convection-with-prolific-lightning-southwest-of-tropical-storm-berthas-center","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/71442","title":{"rendered":"Large area of convection with prolific lightning activity southwest of Tropical Storm Bertha&#8217;s center"},"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\/260723_g19_ir_Bertha.mp4\" playsinline><\/video><figcaption class=\"wp-element-caption\"><em>1-minute GOES-19 Infrared Window images from 0201-1500 UTC on 23 July<\/em><\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">1-minute Mesoscale Domain Sector GOES-19 <em>(GOES-East)<\/em> Infrared Window images <em><strong>(above)<\/strong><\/em> showed a large and persistent cluster of deep convection that remained southwest of <strong><a href=\"https:\/\/www.nhc.noaa.gov\/archive\/2026\/BERTHA.shtml?\">Tropical Storm Bertha&#8217;s<\/a><\/strong> center during the nighttime hours leading up to sunrise on 23 July 2026.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Pulses of overshooting tops exhibited very cold infrared brightness temperatures of -90 C or lower <em><strong>(below)<\/strong><\/em>.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/07\/260723_0212utc_goes19_infrared_cursor_sample.png\"><img decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/07\/260723_0212utc_goes19_infrared_cursor_sample.png\" alt=\"\"\/><\/a><figcaption class=\"wp-element-caption\">GOES-19 Infrared Window image at 0212 UTC on 23 July [click to enlarge]<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">1-minute <strong><a href=\"https:\/\/www.goes-r.gov\/spacesegment\/glm.html\">GLM<\/a><\/strong> Flash Points <strong>(<em>below)<\/em><\/strong> revealed prolific lightning activity associated with the large and persistent cluster of convection. The NHC Forecast Discussion at <strong><a href=\"https:\/\/www.nhc.noaa.gov\/archive\/2026\/al02\/al022026.discus.016.shtml\">0900 UTC<\/a><\/strong> mentioned that &#8220;there has been a persistent supercell thunderstorm with a mesocyclone moving westward through Bertha&#8217;s southwestern quadrant&#8221;.<\/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\/260723_g19_ir_glm_Bertha.mp4\" playsinline><\/video><figcaption class=\"wp-element-caption\"><em>1-minute GOES-19 Infrared Window images with an overlay of GLM Flash Points, from 0201-1500 UTC on 23 July<\/em><\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Some of the GLM Flash Points exhibited an unusually long duration and large flash area <strong><em>(below)<\/em><\/strong>. Over oceans, the average GLM flash duration is 0.345 sec, with an average flash area of 570 km<sup>2<\/sup> (<strong><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/07\/noaa_45194_DS1.pdf\">reference<\/a><\/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\/260723_0409utc_goes19_infrared_glmFlashPoint_cursor_sample.png\"><img decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/07\/260723_0409utc_goes19_infrared_glmFlashPoint_cursor_sample.png\" alt=\"\"\/><\/a><figcaption class=\"wp-element-caption\"><em>GOES-19 Infrared Window image at 0409 UTC on 23 July, with a cursor sample of a GLM Flash Point [click to enlarge]<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">While the official intensity of Bertha was 40 knots at that time, Ultra High Resolution ASCAT winds from Metop-B <em><strong>(below)<\/strong><\/em> showed 2 pockets of surface winds in excess of 50 knots (lighter shades of violet). These higher surface wind speeds may have been related to the aforementioned supercell thunderstorm with a mesocyclone.<\/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\/260723_0215utc_metopB_ascat.png\"><img decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/07\/260723_0215utc_metopB_ascat.png\" alt=\"\"\/><\/a><figcaption class=\"wp-element-caption\"><em>Metop-B Ultra High Resolution ASCAT winds at 0215 UTC on 23 July [click to enlarge]<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">A nighttime NOAA-20 VIIRS Day\/Night Band image <em><strong>(below)<\/strong><\/em> displayed concentric mesospheric airglow waves (<strong><a href=\"http:\/\/www.pnas.org\/content\/early\/2012\/09\/05\/1207034109.full.pdf\">reference<\/a><\/strong>) that were propagating southward and westward from the large convective cluster. A few bright &#8220;lightning streak&#8221; signatures were apparent closer to the coast, which was where the core of the convective cluster was located. The Moon had already set over the western Gulf of Mexico prior to this time, so there was only atmospheric airglow to faintly illuminate any cloud features.<\/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\/260723_0757utc_noaa20_viirs_dayNightBand_Bertha.png\"><img decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/07\/260723_0757utc_noaa20_viirs_dayNightBand_Bertha.png\" alt=\"\"\/><\/a><figcaption class=\"wp-element-caption\"><em>NOAA-20 (mislabeled by AWIPS as NPP) VIIRS Day\/Night Band image valid at <strong><a href=\"https:\/\/www.ssec.wisc.edu\/datacenter\/polar_orbit_tracks\/data\/JPSS-1\/2026\/2026_07_23_204\/NA.gif\">0757 UTC<\/a><\/strong> on 23 July [click to enlarge]<\/em><\/figcaption><\/figure>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>1-minute Mesoscale Domain Sector GOES-19 (GOES-East) Infrared Window images (above) showed a large and persistent cluster of deep convection that remained southwest of Tropical Storm Bertha&#8217;s center during the nighttime hours leading up to sunrise on 23 July 2026. Pulses of overshooting tops exhibited very cold infrared brightness temperatures of -90 C or lower (below). [&hellip;]<\/p>\n","protected":false},"author":18,"featured_media":71443,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[76,159,30,58,78,25,2,48],"tags":[],"class_list":["post-71442","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-glm","category-goes-19","category-lightning","category-metop","category-noaa-20","category-satellite-winds","category-tropical-cyclones","category-viirs"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/71442","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=71442"}],"version-history":[{"count":26,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/71442\/revisions"}],"predecessor-version":[{"id":71492,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/71442\/revisions\/71492"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/71443"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=71442"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=71442"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=71442"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}