{"id":72564,"date":"2026-10-09T19:32:00","date_gmt":"2026-10-09T19:32:00","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=72564"},"modified":"2026-10-11T00:14:40","modified_gmt":"2026-10-11T00:14:40","slug":"hurricane-isaias-reaches-category-3-intensity-as-it-moves-closer-to-the-gulf-coast","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/72564","title":{"rendered":"Hurricane Isaias reaches Category 3 intensity south of the Gulf Coast, eventually making landfall along the Florida Panhandle"},"content":{"rendered":"\n<figure class=\"wp-block-video aligncenter\"><video autoplay controls loop muted src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/10\/261009_g19_30sec_ir_Hur_Isa2.mp4\" playsinline><\/video><figcaption class=\"wp-element-caption\"><em>30-second GOES-19 Infrared Window images with plots of GLM Flash Points, from 0930-2100 UTC on 09 October<\/em><\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Overlapping 1-minute Mesoscale Domain Sectors provided GOES-19 <em>(GOES-East)<\/em> images at 30-second intervals &#8212; Infrared Window imagery <strong><em>(above)<\/em><\/strong> showed <strong><a href=\"https:\/\/www.nhc.noaa.gov\/archive\/2026\/ISAIAS.shtml?\">Hurricane Isaias<\/a><\/strong> moving toward the US Gulf Coast on 09 October 2026. Isaias reached Category 3 intensity at 1220 UTC (<strong><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/10\/261009_1220utc_g19_ir_Isaias_Cat3.png\">Infrared image<\/a><\/strong> | <strong><a href=\"https:\/\/www.nhc.noaa.gov\/archive\/2026\/al09\/al092026.update.10091218.shtml\">NHC advisory<\/a><\/strong>). The coldest cloud-top infrared brightness temperatures were in the -85 to -88 C range (darker shades of purple). GLM Flash Points displayed occasional lightning activity within the core of Isaias.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">30-second sunrise-to-sunset GOES-19 <strong><a href=\"https:\/\/cimss.ssec.wisc.edu\/goes\/OCLOFactSheetPDFs\/ABIQuickGuide_CIMSSRGB_v2.pdf\">CIMSS Natural Color RGB<\/a><\/strong> images created using <strong><a href=\"https:\/\/www.ssec.wisc.edu\/software\/geo2grid\/\">Geo2Grid<\/a><\/strong> are shown below.<\/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\/10\/261009_g19_cimssTC_Isaias.mov\" playsinline><\/video><figcaption class=\"wp-element-caption\"><em>30-second CIMSS Natural  Color RGB images, from 1200-2310 UTC on 09 October (courtesy Mat Gunshor, CIMSS)<\/em><\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Although Isaias was moving through an environment of rather high southwesterly vertical wind shear <strong><em>(below)<\/em><\/strong>, the shear direction generally aligning with the storm motion likely helped to mitigate unfavorable shear effects.<\/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\/10\/261009_g19_ir_1300utcShear_anim.mp4\" playsinline><\/video><figcaption class=\"wp-element-caption\"><em>GOES-19 Infrared Window images with an overlay of contours and streamlines of deep-layer wind shear at 1300 UTC on 09 October<\/em><\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Isaias passed over a patch of fairly high Ocean Heat Content <strong><em>(below)<\/em><\/strong>, which may have played a role in its intensification to Category 3.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/10\/261009_ohc_track.gif\" alt=\"\"\/><figcaption class=\"wp-element-caption\"><em>Track of Isaias plotted over an analysis of Ocean Heat Content<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">While Isaias was still a Category 2 storm, a well-defined eye was depicted in microwave imagery from ATMS and DMSP-18 <strong><em>(below)<\/em><\/strong>.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/10\/261009_0740utc_atms.gif\" alt=\"\"\/><figcaption class=\"wp-element-caption\"><em>183 GHz ATMS microwave image at 0740 UTC on 09 October<\/em><\/figcaption><\/figure>\n<\/div>\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/10\/261009_1040utc_dmsp18_ssmis.gif\" alt=\"\"\/><figcaption class=\"wp-element-caption\"><em>85 GHz DMSP-18 SSMIS microwave image at 1040 UTC on 09 October<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">Later in the day, after Isaias had reached Category 3 intensity, microwave images from ATMS and DMSP-18 <strong><em>(below)<\/em><\/strong> continued to display an eye &#8212; although the eyewall had eroded along the southern edge.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/10\/261009_1855utc_atms.gif\" alt=\"\"\/><figcaption class=\"wp-element-caption\"><em>183 GHz ATMS microwave image at 1855 UTC on 09 October<\/em><\/figcaption><\/figure>\n<\/div>\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/10\/261009_2158utc_dmsp18_ssmis.gif\" alt=\"\"\/><figcaption class=\"wp-element-caption\"><em>85 GHz DMSP-18 SSMIS microwave image at 2158 UTC on 09 October<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">In the GOES-19 Infrared imagery, a sustained and distinct eye was no longer evident after about 1400 UTC &#8212; but the <strong><a href=\"https:\/\/tropic.ssec.wisc.edu\/real-time\/mimtc2\/tc.shtml\">MIMIC-TC<\/a><\/strong> product <strong><em>(below)<\/em><\/strong> showed the slowly-eroding eye structure for a longer period of time. <\/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\/10\/261009_mimicTC_Iasaias_anim.mp4\" playsinline><\/video><figcaption class=\"wp-element-caption\"><em>15-minute MIMIC-TC imagery, from 0000 UTC on 09 October to 0000 UTC on 10 October<\/em><\/figcaption><\/figure>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\">=================================================<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A closer view of 30-second GOES-19 Infrared Window images <strong><em>(below)<\/em><\/strong> showed Category 3 Hurricane Isaias as it approached the Gulf Coast and eventually made landfall near Destin, Florida (METAR identifier KDTS) at <strong><a href=\"https:\/\/www.nhc.noaa.gov\/archive\/2026\/al09\/al092026.update.10100129.shtml\">0130 UTC<\/a><\/strong> on 10 October (weakening to a high-end Category 2 storm just prior to landfall). After landfall, GOES-19 cloud-top infrared brightness temperatures warmed and GLM-based lightning activity decreased.<\/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\/10\/261009_g19_30sec_ir_Hur_Isa_landfall.mp4\" playsinline><\/video><figcaption class=\"wp-element-caption\"><em>30-second GOES-19 Infrared Window images with plots of GLM Flash Points, from 1856 UTC on 09 October to 0200 UTC on 10 October<\/em><\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Shortly after the time of landfall, Isaias produced a wind gust of 99 knots (114 mph) at Whiting Field Naval Air Station KNDZ<strong><em> (below)<\/em><\/strong>. A <strong><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/10\/261010_kmob_pns_winds.text\">list of wind gusts<\/a><\/strong> included 117 mph at Oriole Beach.<\/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\/10\/261010_0200utc_g19_ir_kndzMETAR_G99.png\"><img decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/10\/261010_0200utc_g19_ir_kndzMETAR_G99.png\" alt=\"\"\/><\/a><figcaption class=\"wp-element-caption\"><em>GOES-19 Infrared Window image at 0200 UTC on 10 October, with a cursor sample of the METAR report at KNDZ<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">About 1.5 hours prior to landfall, offshore <strong><a href=\"https:\/\/www.star.nesdis.noaa.gov\/socd\/mecb\/sar\/sarwinds_tropical.php?year=latest\">Synthetic Aperture Radar<\/a><\/strong> (SAR) wind speeds <em><strong>(below)<\/strong><\/em> were as high as 109.1 knots in the <strong><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/10\/261009_2352utc_s1c_sar_NWquadrant.png\">NW quadrant<\/a><\/strong> of Isaias and 110.3 knots in the <strong><a href=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/10\/261009_2352utc_sar_SWquadrant.png\">SW quadrant<\/a><\/strong> of Isaias.<\/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\/10\/261009_2352utc_s1c_sar_Isaias.png\"><img decoding=\"async\" src=\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2026\/10\/261009_2352utc_s1c_sar_Isaias.png\" alt=\"\"\/><\/a><figcaption class=\"wp-element-caption\"><em>Sentinel-1C Synthetic Aperture Radar surface wind speed at 2352 UTC on 09 October [click to enlarge]<\/em><\/figcaption><\/figure>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Overlapping 1-minute Mesoscale Domain Sectors provided GOES-19 (GOES-East) images at 30-second intervals &#8212; Infrared Window imagery (above) showed Hurricane Isaias moving toward the US Gulf Coast on 09 October 2026. Isaias reached Category 3 intensity at 1220 UTC (Infrared image | NHC advisory). The coldest cloud-top infrared brightness temperatures were in the -85 to -88 [&hellip;]<\/p>\n","protected":false},"author":18,"featured_media":72565,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[89,56,132,76,159,30,79,45,104,25,2],"tags":[],"class_list":["post-72564","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-atms","category-dmsp","category-geo2grid","category-glm","category-goes-19","category-lightning","category-microwave","category-redgreenblue-rgb-images","category-sar","category-satellite-winds","category-tropical-cyclones"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/72564","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=72564"}],"version-history":[{"count":43,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/72564\/revisions"}],"predecessor-version":[{"id":72613,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/72564\/revisions\/72613"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/72565"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=72564"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=72564"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=72564"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}