{"id":69496,"date":"2026-03-18T23:59:00","date_gmt":"2026-03-18T23:59:00","guid":{"rendered":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=69496"},"modified":"2026-03-20T20:16:19","modified_gmt":"2026-03-20T20:16:19","slug":"cyclone-narelle-rapidly-intensifies-over-the-coral-sea","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/69496","title":{"rendered":"Cyclone Narelle rapidly intensifies to a Category 4 storm over the Coral Sea, then makes landfall along Australia’s York Peninsula"},"content":{"rendered":"

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2.5-minute Himawari-9 Infrared images, from 0602 UTC on 18 March to 0119 UTC on 19 March [click to play animated GIF | MP4<\/strong><\/a>]<\/p><\/div>2.5-minute Target Sector JMA<\/strong><\/a> Himawari-9 AHI<\/strong><\/a> Infrared images (above)<\/em><\/strong> showed Cyclone Narelle as it was rapidly intensifying over the Coral Sea on 18 March 2026 — becoming a Category 2 storm by 1200 UTC, a Category 3 storm by 1800 UTC and a Category 4 storm by 0000 UTC (ADT<\/strong><\/a> | SATCON<\/strong><\/a>). The coldest cloud-top infrared brightness temperatures were in the -90 to -95C range.<\/p>\n

Himawari-9 Infrared \/ Water Vapor Difference images (below)<\/strong><\/em> exhibited large difference values — highlighting cloud tops that were significantly overshooting the tropopause.<\/p>\n

Himawari-9 Infrared \/ water Vapor Difference images<\/p><\/div>\n

Himawari-9 Infrared images with an overlay of Deep-Layer Wind Shear (below)<\/em><\/strong> indicated that Narelle was moving through an environment of modest shear — which, along with warm Sea Surface Temperatures<\/strong><\/a> favored further intensification.<\/p>\n

Himawari-9 Infrared images, with an overlay of contours and streamlines of Deep-Layer Wind Shear at 1800 UTC on 18 March<\/p><\/div>\n

DMSP-18 SSMIS Microwave image at 0622 UTC on 18 March<\/p><\/div>\n

Comparing DMSP SSMIS Microwave images at 0622 UTC (above)<\/strong><\/em>\u00a0and 2004 UTC (below)<\/strong><\/em>, the eyewall had become more consolidated and the eye diameter contracted a bit during that time period (signatures of an intensifying tropical cyclone).<\/p>\n

DMSP-17 SSMIS Microwave image at 2004 UTC on 18 March<\/p><\/div>\n

===== 19 March Update =====<\/strong><\/p>\n

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RCM-1 SAR wind speed image at 0847 UTC [click to enlarge]<\/p><\/div>A Radar Constellation Mission (RCM-1) Synthetic Aperture Radar (SAR) wind speed image at 0847 UTC on 19 March (above)<\/strong><\/em>\u00a0depicted a maximum of 130 kts<\/strong><\/a> in the SW quadrant of Narelle.<\/p>\n

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NOAA-21 VIIRS Day\/Night Band image at 1444 UTC on 19 March [click to enlarge]<\/p><\/div>A nocturnal NOAA-21 (mislabeled by AWIPS as NPP) VIIRS Day\/Night Band image (above)<\/strong><\/em> revealed concentric mesospheric airglow waves (reference<\/strong><\/a>) propagating outward from Category 4 Cyclone Narelle as the storm was just east of Australia’s York Peninsula.<\/p>\n

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2.5-minute Himawari-9 Infrared images, from 0602-2102 UTC on 19 March [click to play animated GIF | MP4<\/strong><\/a>]<\/p><\/div>2.5-minute Himawari-9 Infrared images (above)<\/strong><\/em> suggest that Category 4 Cyclone Narelle made landfall along Australia’s York Peninsula just after 2100 UTC on 19 March. During the hours preceding landfall, pulses of overshooting tops exhibited infrared brightness temperatures of -90C and colder (yellow pixels embedded within darker purple regions).<\/p>\n

DMSP-17 SSMIS Microwave image at 1950 UTC on 19 March<\/p><\/div>\n

Even though the eye of Narelle was becoming increasingly cloud-filled toward landfall in Himawari-9 Infrared imagery, a microwave image from DMSP-17 SSMIS at 1950 UTC (above)<\/strong><\/em>\u00a0still displayed a distinct eye signature.<\/p>\n","protected":false},"excerpt":{"rendered":"

2.5-minute Target Sector JMA Himawari-9 AHI Infrared images (above) showed Cyclone Narelle as it was rapidly intensifying over the Coral Sea on 18 March 2026 — becoming a Category 2 storm by 1200 UTC, a Category 3 storm by 1800 UTC and a Category 4 storm by 0000 UTC (ADT | SATCON). The coldest cloud-top […]<\/p>\n","protected":false},"author":18,"featured_media":69517,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[56,73,79,131,104,25,2,48],"tags":[],"class_list":["post-69496","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-dmsp","category-himawari-9","category-microwave","category-noaa-21","category-sar","category-satellite-winds","category-tropical-cyclones","category-viirs"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/69496","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=69496"}],"version-history":[{"count":23,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/69496\/revisions"}],"predecessor-version":[{"id":69531,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/69496\/revisions\/69531"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/69517"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=69496"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=69496"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=69496"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}