Target Sector (2.5-minute interval) JMA Himawari-9 AHI Clean Infrared Window (10.4 µm) images (above) and Red Visible (0.64 µm) mages (below) showed Tropical Storm Bolaven as it intensified to become a Category 1 Typhoon just southeast of the Mariana Islands at 0000 UTC (SATCON | JTWC advisory) on 10 October 2023. The coldest cloud-top infrared brightness temperatures, associated with... Read More

Tropical Storm Bolaven formed southeast of the Mariana Islands at 1200 UTC on 07 October 2023 (about 540 miles southeast of Guam, according to the initial advisory issued by JTWC). With sufficient illumination from the Moon (which was in the Waning Crescent phase, at 41% of Full), a nighttime Suomi-NPP VIIRS... Read More

Target Sector (2.5-minute interval) JMA Himawari-9 AHI Clean Infrared Window (10.4 µm) images (above) showed Typhoon Koinu after it reached Category 4 intensity at 0600 UTC (SATCON) on 04 October 2023. The coldest cloud-top infrared brightness temperatures (-80 to -89C, shades of violet to purple) were generally confined to the southern semicircle of the storm.... Read More

Target Sector (2.5-minute interval) JMA Himawari-9 AHI Visible and Infrared images (above) showed Typhoon Koina as it intensfied to a Category 3 storm by 0000 UTC on 02 October 2023 (SATCON). Cloud-top infrared brightness temperatures were as cold as -90C.Just prior to the start of the Himawari-9 animation, an image of RCM-3 Synthetic Aperture Radar (SAR) winds... Read More