![](\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/images\/2025\/04\/HIM09_VIS_IR_ERROL_16APR2025_loop_HIMAWARI-9_2025105_230215_2025106_094215.gif\")
<\/a>2.5-minute JMA Himawari-9 Red Visible (0.64 \u00b5m, left) and Clean Infrared Window (10.4 \u00b5m, right) images, from 2302 UTC on 15 April to 0942 UTC on 16 April [click to play animated GIF | MP4<\/strong><\/a>]<\/p><\/div>Target Sector (2.5-minute interval) JMA Himawari-9 AHI Red Visible (0.64 \u00b5m) and Clean Infrared Window (10.4 \u00b5m) images (above)<\/strong><\/em> showed Cyclone Errol as it was rapidly intensifying off the northern coast of Western Australia on 15-16 April 2025. About 2 hours after the end of the above animation, Errol peaked at 140 kts — Category 5 intensity — at 1200 UTC (SATCON<\/strong><\/a>). Errol exhibited a pinhole eye during the time period shown — a feature frequently observed with rapidly-intensifying tropical cyclones. Cloud-top infrared brightness temperatures in the eyewall region of Errol were in the -80s C (shades of violet to purple).<\/p>\n A NOAA-20 VIIRS Day\/Night Band image valid at 0503 UTC (below)<\/strong><\/em> provided a higher-resolution view of the 10-mile diameter pinhole eye.<\/p>\n NOAA-20 VIIRS Day\/Night Band (0.7 \u00b5m) image valid at 0503 UTC on 16 April [click to enlarge]<\/p><\/div>A Sentinel-1A Synthetic Aperture Radar (SAR) image (source<\/strong><\/a>) at 1610 UTC (below)<\/strong><\/em> sensed a maximum radial wind velocity of 124.8 knots in the northeast quadrant of Errol.<\/p>\n Sentinel-1A SAR image at 1032 UTC on 16 April [click to enlarge]<\/p><\/div>Factors favoring Errol’s rapid intensification included very warm water<\/strong><\/a> that the storm was traversing, and an environment of low deep-layer wind shear<\/strong><\/a> (below)<\/strong><\/em>. Sea Surface Temperature and Wind Shear images were sourced from the CIMSS Tropical Cyclones<\/strong><\/a> site.<\/p>\n<\/a><\/a>