{"id":30090,"date":"2018-10-01T23:02:18","date_gmt":"2018-10-01T23:02:18","guid":{"rendered":"http:\/\/cimss.ssec.wisc.edu\/satellite-blog\/?p=30090"},"modified":"2018-10-03T00:51:28","modified_gmt":"2018-10-03T00:51:28","slug":"hurricane-walaka","status":"publish","type":"post","link":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/archives\/30090","title":{"rendered":"Hurricane Walaka"},"content":{"rendered":"

\"GOES-15<\/a>

GOES-15 Infrared Window (10.7 \u00b5m)<\/em> images [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>GOES-15 (GOES-West) Infrared Window (10.7 \u00b5m) images (above)<\/strong><\/em> showed the formation of a well-defined eye of Hurricane Walaka<\/strong><\/a> during a period of rapid intensification (ADT<\/strong><\/a> | SATCON<\/strong><\/a>) from 0000-2330 UTC on 01 October 2018; Walaka was classified a Category 5<\/strong><\/a> hurricane as of the 02 October 00 UTC advisory. Walaka was moving over very warm water with Sea Surface Temperatures of 30\u00baC<\/strong><\/a>.<\/p>\n

A 1536 UTC DMSP-16 SSMIS Microwave (85 GHz) image from the CIMSS Tropical Cyclones<\/strong><\/a> site (below)<\/strong> <\/em>revealed a small eye (reported to be 20 nautical miles in diameter at 21 UTC).<\/p>\n

\"DMSP-16<\/a>

DMSP-16 SSMIS (85 GHz)<\/em> Microwave image [click to enlarge]<\/p><\/div>A side-by-side comparison of JMA<\/strong><\/a> Himawari-8 and GOES-15 Infrared Window images (below)<\/strong><\/em> showed Walaka from 2 different satellite perspectives — the superior spatial resolution of Himawari-8 (2 km, vs 4 km for GOES-15)<\/em> was offset by the much larger viewing angle. Cloud-top infrared brightness temperatures were -80\u00baC and colder (shades of violet) from both satellites early in the animation, but warmed somewhat into the -70 to -75\u00baC range by 00 UTC on 02 October.<\/p>\n

\"Infrared<\/a>

Infrared Window images from Himawari-8 (10.3 \u00b5m, left)<\/em> and GOES-15 (10.7 \u00b5m, right)<\/em> [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>\n

===== 02 October Update =====<\/strong><\/p>\n

\"NOAA-20<\/a>

NOAA-20 VIIRS Day\/Night Band (0.7 \u00b5m)<\/em> and Infrared Window (11.45 \u00b5m)<\/em> images [click to enlarge]<\/p><\/div>Walaka remained classified as a Category 5 hurricane until the 15 UTC advisory on 02 October, when it was assigned Category 4 status after some weakening as a result of an overnight eyewall replacement cycle. A toggle between NOAA-20 VIIRS Day\/Night Band (0.7 \u00b5m) and Infrared Window (11.45 \u00b5m) images (above; <\/strong>courtesy of William Straka, CIMSS)<\/em> showed the storm at 1240 UTC or 2:40 am local time.<\/p>\n

GOES-15 Infrared Window (10.7 \u00b5m) images (below)<\/strong><\/em> showed the northward motion of Waleka. Given that the storm was forecast to pass very close to Johnston Atoll<\/strong><\/a>, the US Coast Guard was dispatched to evacuate personnel<\/strong><\/a> on Johnston Island.<\/p>\n

\"GOES-15<\/a>

GOES-15 Infrared Window (10.7 \u00b5m)<\/em> images; the white circle shows the location of Johnston Atoll [click to play animation | MP4<\/strong><\/a>]<\/p><\/div>The MIMIC-TC<\/strong><\/a> product (below)<\/strong><\/em> showed the eyewall replacement cycle during the 0000-1445 UTC period.<\/p>\n

\"MIMIC-TC<\/a>

MIMIC-TC morphed microwave product [click to play animation]<\/p><\/div>Around 1830 UTC, a toggle between GOES-15 Infrared (10.7 \u00b5m) and GPM GMI Microwave (85 GHz) images (below)<\/strong><\/em> showed a small eye, with evidence of a larger outer eyewall suggesting that another eyewall replacement cycle was taking place.<\/p>\n

\"GOES-15<\/a>

GOES-15 Infrared Window (10.7 \u00b5m) and GPM GMI Microwave (85 GHz) images [click to enlarge]<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"

GOES-15 (GOES-West) Infrared Window (10.7 \u00b5m) images (above) showed the formation of a well-defined eye of Hurricane Walaka during a period of rapid intensification (ADT | SATCON) from 0000-2330 UTC on 01 October 2018; Walaka was classified a Category 5 hurricane as of the 02 October 00 UTC advisory. Walaka was moving over very warm […]<\/p>\n","protected":false},"author":18,"featured_media":30092,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[56,43,62,79,78,47,2,48],"tags":[],"class_list":["post-30090","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-dmsp","category-goes-15","category-himawari-8","category-microwave","category-noaa-20","category-other-satellites","category-tropical-cyclones","category-viirs"],"acf":[],"_links":{"self":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/30090","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=30090"}],"version-history":[{"count":11,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/30090\/revisions"}],"predecessor-version":[{"id":30105,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/posts\/30090\/revisions\/30105"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media\/30092"}],"wp:attachment":[{"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/media?parent=30090"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/categories?post=30090"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-json\/wp\/v2\/tags?post=30090"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}