![](\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2023\/10\/231002_himawari9_visible_infrared_Koinu_anim.gif\")
<\/a>JMA Himawari-9 \u201cRed” Visible (0.64 \u00b5m, top) and \u201cClean\u201d Infrared Window (10.4 \u00b5m, bottom) images, from 2132 UTC on 01 October to 0902 UTC on 02 October [click to play animated GIF | MP4<\/strong><\/a>]<\/p><\/div>Target Sector<\/strong><\/a>\u00a0(2.5-minute interval)\u00a0JMA<\/strong><\/a>\u00a0Himawari-9\u00a0AHI<\/strong><\/a>\u00a0Visible and Infrared images\u00a0(above)<\/strong><\/em> showed Typhoon Koina as it intensfied to a Category 3 storm by 0000 UTC on 02 October 2023 (SATCON<\/strong><\/a>). Cloud-top infrared brightness temperatures were as cold as -90C.<\/p>\n Just prior to the start of the Himawari-9 animation, an image of RCM-3 Synthetic Aperture Radar (SAR) winds at 2122 UTC on 01 October (source<\/strong><\/a>) is shown below — which depicted a narrow but fully closed eyewall.<\/p>\n RCM-3 Synthetic Aperture Radar image at 2122 UTC on 01 October [click to enlarge]<\/p><\/div>Later in the day, Himawari-9 Infrared Window (11.2 \u00b5m) images with an overlay of\u00a0deep-layer wind shear<\/strong><\/a> at 2100 UTC — from the CIMSS Tropical Cyclones<\/strong><\/a>\u00a0site\u00a0(below)<\/strong><\/em> indicated that Koinu was moving through an environment where the shear (around 15 knots) was favorable. In addition, Koinu was traversing warm water (Ocean Heat Content<\/strong><\/a>\u00a0|\u00a0Sea Surface Temperature<\/strong><\/a>).<\/p>\n<\/a>