![\"Suomi](\"https:\/\/cimss.ssec.wisc.edu\/satellite-blog\/wp-content\/uploads\/sites\/5\/2019\/03\/190321_1716utc_suomiNPP_dayNightBand_infrared_Cyclone_Veronica_anim.gif\")
<\/a>Suomi NPP VIIRS Day\/Night Band (0.7 \u00b5m)<\/em> and Infrared Window (11.45 \u00b5m)<\/em> images at 1716 UTC [click to enlarge]<\/p><\/div>A toggle between Suomi NPP VIIRS Day\/Night Band (0.7 \u00b5m) and Infrared Window (11.45 \u00b5m) images (above)<\/strong><\/em> showed Category 4 Cyclone Veronica off the northern coast of Western Australia at 1716 UTC on 21 March 2019. Ample illumination from a Full Moon maximized the “visible image at night” capability of the Day\/Night Band.<\/p>\n In a comparison of Microwave images from Suomi NPP ATMS at 1716 UTC and from GCOM-W1 AMSR2 at 1732 UTC (below)<\/strong>,<\/em> an eyewall that was nearly completely closed was apparent. Suomi NPP and GCOM-W1 images courtesy of William Straka, CIMSS.<\/p>\n Microwave images from Suomi NPP ATMS at 1716 UTC and from GCOM-W1 AMSR2 at 1732 UTC [click to enlarge]<\/p><\/div>A DMSP-17 SSMIS Microwave (85 GHz) image at 2246 UTC from the CIMSS Tropical Cyclones<\/strong><\/a> site is shown below. The deep-layer Wind Shear<\/strong><\/a> at 21 UTC was low (green contours),<\/em> and Sea Surface Temperature values were quite high — both factors favorable for continued intensification as Veronica moved slowly toward the coast.<\/p>\n DMSP-17 SSMIS Microwave (85 GHz) image at 2246 UTC, with an overlay of 21 UTC deep-layer Wind Shear, and Sea Surface Temperature [click to enlarge]<\/p><\/div>2.5-minute interval rapid scan Himawari-8 Infrared Window (10.4 \u00b5m) images (below)<\/strong><\/em> showed increasing organization to the eyewall structure. At times the cloud-top infrared brightness temperatures were -90\u00baC and colder (yellow pixels embedded within darker purple)<\/em>. Note: the rapid scan sector was re-poositioned eastward at 0100 UTC (to monitor Cyclone Trevor), so 10-minute imaging resumed after that time.<\/p>\n<\/a><\/a>