![\"GOES-16](\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2018\/10\/181009_goes16_infrared_metop_ascat_Michael_anim.gif\")
<\/a>GOES-16 “Clean” Infrared Window (10.3 \u00b5m)<\/em> image, with Metop-A ASCAT surface scatterometer winds [click to enlarge]<\/p><\/div>Metop-A ASCAT scatterometer data (above)<\/strong><\/em> showed surface wind speeds as high as 64 knots<\/strong><\/a> near the storm center while Michael<\/strong><\/a> was at Category 2 intensity just northwest of Cuba at 0307 UTC on 09 October 2018.<\/p>\n A toggle between Suomi NPP VIIRS Day\/Night Band (0.7 \u00b5m) and Infrared Window (11.45 \u00b5m) images at 0752 UTC (below;<\/strong> courtesy of William Straka, CIMSS)<\/em> revealed transverse banding north of the storm center on the Infrared image, and mesospheric airglow waves propagating westward away from Michael on the Day\/Night Band image.<\/p>\n Suomi NPP VIIRS Day\/Night Band (0.7 \u00b5m)<\/em> and Infrared Window (11.45 \u00b5m)<\/em> images [click to enlarge]<\/p><\/div>5-minute GOES-16 (GOES-East)<\/em> “Clean” Infrared Window (10.3 \u00b5m<\/strong><\/a>) images from 0517-1332 UTC (below)<\/strong><\/em> showed a series of relatively brief convective bursts around the storm center, but in general Michael exhibited a somewhat disorganized appearance during that time period.<\/p>\n GOES-16 “Clean” Infrared Window (10.3 \u00b5m)<\/em> images [click to play MP4 animation]<\/p><\/div>After sunrise, 1-minute Mesoscale Domain Sector<\/strong><\/a> GOES-16 “Red” Visible (0.64 \u00b5m<\/strong><\/a>) images (below)<\/strong><\/em> revealed the gradual formation of a more well-defined eye during the day, with episodic clusters of convective “hot towers” developing in the southeastern and eastern portions of the eyewall — which then rotated around to the north and northwest of the eye. By 18 UTC<\/strong><\/a> Michael had intensified to a Category 3 storm.<\/p>\n GOES-16 “Red” Visible (0.64 \u00b5m)<\/em> images [click to play MP4 animation]<\/p><\/div>1-minute GOES-16 “Clean” Infrared Window images (below)<\/strong><\/em> indicated that infrared brightness temperatures associated with these hot towers were often as cold as -80\u00ba to -89\u00baC (violet to darker purple enhancement)<\/em>.<\/p>\n GOES-16 “Clean” Infrared Window (10.3 \u00b5m)<\/em> images [click to play MP4 animation]<\/p><\/div>Michael had been encountering unfavorable deep-layer wind shear<\/strong><\/a> and had also been moving over a pocket of water with low Ocean Heat Content northwest of Cuba (below)<\/strong><\/em>. However, once the hurricane began to move over waters having higher OHC in addition to warm Sea Surface Temperature, it gradually began to intensify from a Category 2 to a Category 3.<\/p>\n<\/a><\/a><\/a><\/a>