Typhoon Kammuri in the West Pacific Ocean, with record cold cloud-top temperatures2.5-minute interval JMA Himawari-8 AHI “Clean” Infrared Window (10.4 µm) images (above) showed a large canopy of cold cloud-top infrared brightness temperatures (BTs) associated with Category 1 Typhoon Kammuri in the West Pacific Ocean on 30 November 2019. Between 00 UTC and 05 UTC, many of the pulsing overshooting tops exhibited BTs -100ºC or colder (shades of red embedded in black on the coldest end of the scale).
Plots of the coldest overshooting top 10.4 µm brightness temperatures on Himawari-8 Target Sector (2.5-minute interval) and Full Disk (10-minute interval) images during the 0002-0502 UTC time period on 30 November (below) showed that the closest (in time**) Full Disk image BTs were often within a degree C of the Target Sector images — but the magnitude of rapid fluctuations of BT seen in the 2.5-minute data were well not captured by the 10-minute data. For the 4 Target Sector images exhibiting BTs of -103ºC and colder (0112, 0127, 0204 and 0259 UTC) only one of the closely-corresponding Full Disk images exhibited a similarly cold BT (0110 UTC, with -103.0ºC). The coldest Target Sector BT was -103.55ºC at 02:59:44 UTC, while the coldest Full Disk BT was -103.0ºC at 01:13:34 UTC.
**The actual time that closely-corresponding Target Sector and Full Disk scans were imaging Kammuri differed by about 1 minute and 15 seconds — for example, the 01:12:15 UTC Target Sector scanned Kammuri’s coldest overshooting tops at 01:12:19, while the 01:10:00 Full Disk scanned those same overshooting tops at 01:13:34 UTC.NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images at 0421 UTC as viewed using RealEarth (below) revealed an area of very cold cloud-top infrared BTs (highlighted by the yellow region near the center of the storm). The coldest BT within that yellow area was -109.35ºC — which could qualify as the coldest cloud-top temperature on record as sensed by a meteorological satellite (Weather Underground). In addition, on the plot of Himawari-8 infrared BTs shown above it can be seen that the previous record for coldest documented BT (-102.2ºC with Tropical Cyclone Hilda in 1990) was eclipsed on a total of 9 Target Sector and 4 Full Disk images. The NOAA-20 VIIRS Infrared image at 0421 UTC is shown below with 2 different color enhancements — the darker blue colors of the 160-to-200 K enhancement help to highlight the colder BT regions (including the coldest 163.8 K or -109.35ºC pixel). The Himawari-8 Infrared image closest (time-wise) to the NOAA-20 image was at 04:22:15 UTC, and its coldest cloud-top BT was -102.5ºC. In a toggle between magnified Himawari-8 Visible and Infrared images at that time (below), the -102.5ºC BT was located within the northernmost cluster of red pixels (where shadowing and texture in the Visible image highlighted the overshooting top). The nearest upper air site was Babelthuop Airport/Koror on Palau Island, located south of the storm — the coldest temperature in their 00 UTC rawinsonde data (below) was -81.9ºC at an altitude of 16.7 km. Assuming that the overshooting top cooled at a lapse rate of around 7.5ºC per km of ascent beyond the -81.9ºC tropopause (reference), the altitude of the coldest -109.35ºC cloud top was likely near 19.5 km. During the daylight hours on 30 November, Himawari-8 “Red” Visible (0.64 µm) images (below) revealed widespread cloud-top gravity waves which were moving outward away from intense convection with overshooting tops near the storm center. Many of these gravity waves were propagating along the tops of tendrils of transverse banding — especially within the southern semicircle of Kammuri.
—————————Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images from Suomi NPP at 1604 UTC (above) and NOAA-20 at 1654 UTC (below) showed mesospheric airglow waves propagating southward in the DNB images.
—————————Himawari-8 Water Vapor (6.2 µm) images with contours of Deep-Layer Wind Shear (above) indicated that Kammuri was moving through an environment of low to moderate shear. Himawari-8 Water Vapor images with plots of satellite-derived Atmospheric Motion Vectors (below) showed a well-defined outflow channel north of the tropical cyclone.
Himawari-8 (courtesy JMA) and GEO-KOMPSAT-2A or GK2A (courtesy KMA) visible imagery were combined to create stereoscopic imagery of the storm on 30 November, as shown below from 2100 UTC on 29 November to 0820 UTC on 30 December. View the 3-dimensional image by crossing your eyes and focusing on the third image that becomes apparent in between the two images shown.
10-minute Full Disk images of GK2A Cloud Top Temperature and Cloud Top Height products (source) are shown below. A large canopy of CTT values as cold as -80ºC and CTH values up to 15 km were seen associated with Typhoon Kammuri during the period 0000-0500 UTC.