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

RADARSAT-2 and RCM-3 satellites had nearly simultaneous overpasses over Typhoon Koinu on 3 October 2023, as shown below. (See this blog post from 2 October for more on Koinu) Both SAR analyses showed the strongest winds (nearly 120 knots) in the southern eyewall of the storm, with long interesting wind minima features... 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

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (above) showed Ophelia for a few hours after it became a Tropical Storm at 1800 UTC on 22 September 2023. The low-level circulation center (LLCC) was initially exposed, but deep convection just to the west began to increase in coverage and intensity as it... Read More