![\"\"](\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2021\/09\/210907_himawari8_infrared_Typhoon_Chanthu_anim.gif\")
<\/a>JMA Himawari-8 Infrared Window (10.4 \u00b5m) images [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>\n JMA<\/strong><\/a> Himawari-8 Infrared Window (10.4 \u00b5m) images (above)<\/strong><\/em> displayed Typhoon Chanthu undergoing a period of rapid intensification — with the appearance of a small-diameter “pinhole eye” within just a few hours — from a Category 2 to a Category 4 storm\u00a0 (ADT<\/strong><\/a> | SATCON<\/strong><\/a>) as it moved westward toward the Philippine Sea on 07 September 2021. Chanthu was moving over very warm water (SST<\/strong><\/a> | OHC<\/strong><\/a>), and an analysis of deep-layer wind shear from the CIMSS Tropical Cyclones<\/strong><\/a> site (below)<\/strong><\/em> depicted an environment of light shear — all factors which favored rapid intensification.\u00a0<\/p>\n JMA Himawari-8 Infrared images, with an analysis of deep-layer wind shear at 15 UTC [click to enlarge]\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\u00a0<\/b><\/p><\/div>\n ===== 08 September Update =====<\/strong><\/p>\n Himawari-8 “Red” Visible (0.64 \u00b5m) images [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>\n During the subsequent daytime hours, Chanthu continued its trend of intensification, becoming a Category 5 tropical cyclone at 0600 UTC on 08 September. Himawari-8 Visible (0.64 \u00b5m)\u00a0images (above)<\/strong><\/em> showed the west-southwestward motion of the pinhole eye.<\/p>\n Just prior to the time that Chanthu reached Category 5 intensity, a toggle between VIIRS True Color RGB and Infrared Window (11.45 \u00b5m) images from Suomi NPP as viewed using RealEarth<\/strong><\/a> is shown below. The diameter of the eye appeared to be about 5 miles, which is unusually small.<\/p>\n<\/a><\/a>