![\"NOAA-20](\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2019\/02\/190221_1502utc_noaa20_viirs_dayNightBand_infraredWindow_Typhoon_Wutip_anim.gif\")
<\/a>NOAA-20 VIIRS Day\/Night Band (0.7 \u00b5m)<\/em> and Infrared Window (11.45 \u00b5m)<\/em> images at 1502 UTC [click to enlarge]<\/p><\/div>VIIRS Day\/Night Band (0.7 \u00b5m) and Infrared Window (11.45 \u00b5m) images from NOAA-20 at 1502 UTC (above)<\/strong><\/em> and from Suomi NPP at 1552 UTC (below)<\/strong><\/em> showed Category 2 Typhoon Wutip in the West Pacific Ocean (southeast of Guam)<\/em> on 21 February 2019. With Moon in the Waning Gibbous phase (at 95% of Full),<\/em> ample illumination was provided to highlight the “visible image at night” capability of the Day\/Night Band.<\/p>\n Notable features included deep convection near the storm’s center of circulation (with the presence of subtle cloud-top gravity waves), and transverse banding along the eastern periphery of the cold central dense overcast. Bright pixels seen in the Suomi NPP Day\/Night Band image were the result of clouds being illuminated by lightning activity. VIIRS images courtesy of William Straka, CIMSS.<\/p>\n Suomi NPP VIIRS Day\/Night Band (0.7 \u00b5m)<\/em> and Infrared Window (11.45 \u00b5m)<\/em> images at 1552 UTC [click to enlarge]<\/p><\/div>\n ===== 22 February Update =====<\/strong><\/p>\n Himawari-8 Infrared Window (10.4 \u00b5m)<\/em> images [click to play MP4 animation]<\/p><\/div>Typhoon Wutip intensified to a Category 3 storm on 22 February (ADT<\/strong><\/a> | SATCON<\/strong><\/a>) — rapid scan JMA<\/strong><\/a> Himawari-8 Infrared Window (10.4 \u00b5m) images at 2.5 minute intervals (above)<\/strong><\/em> revealed cloud-top infrared brightness temperatures of -90\u00baC and colder (yellow pixels surrounded by darker purple)<\/em> shortly after 00 UTC<\/strong><\/a>. Multiple convective bursts developed around the center of circulation, and evidence of eye formation was seen for a short time beginning around 1137 UTC<\/strong><\/a>.<\/p>\n Himawari-8 “Red” Visible (0.64 \u00b5m) images of Wutip (below)<\/strong><\/em> showed that a distinct cloud-free eye did not form during that time period.<\/p>\n Himawari-8 “Red” Visible (0.64 \u00b5m)<\/em> images [click to play MP4 animation]<\/p><\/div>A DMSP-17 SSMIS Microwave (85 GHz) image from the CIMSS Tropical Cyclones<\/strong><\/a> site (below)<\/strong><\/em> showed a nearly complete ring of strong convection around the eye region at 0916 UTC. A 24-hour animation of MIMIC-TC<\/strong><\/a> morphed microwave imagery is available here<\/strong><\/a>.<\/p>\n DMSP-17 SSMIS Microwave (85 GHz)<\/em> image [click to enlarge]<\/p><\/div>Prior to becoming a typhoon<\/strong><\/a>, Wutip had been moving over water with warm Sea Surface Temperatures and high Ocean Heat Content values (below)<\/strong><\/em>.<\/p>\n Sea Surface Temperature and Ocean Heat Content [click to enlarge]<\/p><\/div>\n ===== 23 February Update =====<\/strong><\/p>\n Himawari-8 Infrared Window (10.4 \u00b5m)<\/em> images [click to play MP4 animation]<\/p><\/div>2.5-minute rapid scan Himawari-8 Infrared Window (10.4 \u00b5m) images (above)<\/strong><\/em> revealed the formation of a large and well-define eye with an annular eyewall structure as Wutip rapidly intensified (ADT<\/strong><\/a> | SATCON<\/strong><\/a>) to Category 4 Super Typhoon status on 23 February. Mesovortices could be seen rotating within the eye. Wutip became the most intense February typhoon on record in the Northwest Pacific basin.<\/p>\n In a toggle between NOAA-20 VIIRS Day\/Night Band (0.7 \u00b5m) and Infrared Window (11.45 \u00b5m) images at 1602 UTC (below)<\/strong>, <\/em>these mesovortices were also apparent — with the help of reflected moonlight — in the Day\/Night Band.<\/p>\n NOAA-20 VIIRS Day\/Night Band (0.7 \u00b5m)<\/em> and Infrared Window (11.45 \u00b5m)<\/em> images at 1604 UTC [click to enlarge]<\/p><\/div>As noted in a 21 UTC discussion<\/strong><\/a> from the JTWC<\/strong><\/a>, Wutip had a well-defined poleward outflow channel within the upper troposphere (below)<\/strong>,<\/em> which was a favorable factor for its intensification.<\/p>\n<\/a><\/a><\/a><\/a><\/a><\/a><\/a>