Typhoon Kammuri in the West Pacific Ocean, with record cold cloud-top temperatures

November 30th, 2019 |

Himawari-8 "Clean" Infrared Window (10.4 µm) images [click to play animation | MP4]

Himawari-8 “Clean” Infrared Window (10.4 µm) images [click to play animation | MP4]

2.5-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). — the coldest BT was -103.55ºC at 02:59:44 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 would qualify as the coldest cloud-top temperature on record as sensed by a meteorological satellite (Weather Underground).

 NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images at 0420 UTC [click to enlarge]

NOAA-20 VIIRS True Color RGB and Infrared Window (11.45 µm) images at 0421 UTC [click to enlarge]

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).

NOAA-20 VIIRS Infrared Window (11.45 µm), with different color enhancements (credit: William Straka) [click to enlarge]

NOAA-20 VIIRS Infrared Window (11.45 µm) image at 0421 UTC, with 2 different color enhancements (credit: William Straka, CIMSS) [click to enlarge]

On the closest (time-wise) Himawari-8 Infrared image at 04:22:15 UTC, the 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).

Himawari-8 Visible (0.64 µm) and Infrared (10.4 µm) images at 0422 UTC [click to enlarge]

Himawari-8 Visible (0.64 µm) and Infrared (10.4 µm) images at 0422 UTC [click to enlarge]

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.

Plots of 00 UTC and 12 UTC rawinsonde data from Koror, Palau Island [click to enlarge]

Plots of 00 UTC and 12 UTC rawinsonde data from Koror, Palau Island [click to enlarge]

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.

Himawari-8

Himawari-8 “Red” Visible (0.64 µm) images [click to play animation | MP4]

—————————

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1604 UTC [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1604 UTC (credit: William Straka, CIMSS) [click to enlarge]

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.

NOAA-20 Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1654 UTC (credit: William Straka, CIMSS) [click to enlarge]

NOAA-20 Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images at 1654 UTC (credit: William Straka, CIMSS) [click to enlarge]

—————————

6.9 µm) images, with contours of Deep-Layer Wind Shear [click to enlarge]

Himawari-8 Water Vapor (6.2 µm) images, with contours of Deep-Layer Wind Shear [click to enlarge]

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 Water Vapor (6.9 µm) images, with Derived Motion Winds [click to enlarge]

Himawari-8 Water Vapor (6.2 µm) images, with plots of Derived Motion Winds [click to enlarge]


Himawari-8 (courtesy JMA) and GEO-KOMPSAT-2A (courtesy KMA) visible imagery were combined to create stereoscopic imagery of the storm on 30 November, as shown below from 0000 to 0800 UTC (with missing data between 0100 and 0400 UTC).  View the 3-dimensional image by crossing your eyes and focusing on the third image that becomes apparent in between the two images shown.

Visible (0.64 µm) Imagery from Himawari-8 (left) and GK2A (right) from 0000 to 0800 UTC on 30 November 2019 (Click to animate)

Pyrocumulonimbus cloud in eastern Australia

November 22nd, 2019 |

Himawari-8 “Red” Visible (0.64 µm, top), Shortwave Infrared (3.9 µm, middle) and “Clean” Infrared Window (10.4 µm, bottom) [click to play animation | MP4]

Himawari-8 “Red” Visible (0.64 µm, top), Shortwave Infrared (3.9 µm, middle) and “Clean” Infrared Window (10.4 µm, bottom) [click to play animation | MP4]

JMA Himawari-8 AHI “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.4 µm) images (above) showed the development of a pyrocumlonimbus (pyroCb) cloud produced by bush fires northwest of Sydney, Australia (station identifier YSSY) on 22 November 2019 (surface analyses). In the 3.9 µm images, hot thermal signatures of the bush fires (darker black to red pixels) were apparent; in addition, the cloud tops of the pyroCb cloud appeared warmer (darker gray) than surrounding convective cloud tops. The pyroCb exhibited cloud-top 10.4 µm brightness temperatures colder than -40ºC.

VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 as viewed using RealEarth are shown below. Cloud-top 11.45 µm brightness temperatures of the pyroCb were in the -70 to -75ºC range on the later 0407 UTC Suomi NPP image.

VIIRS True Color RGB and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 [click to enlarge]

VIIRS True Color RGB and Infrared Window (11.45 µm) images from Suomi NPP and NOAA-20 [click to enlarge]

The coldest Himawari-8 10.4 µm brightness temperature (BT) associated with the southernmost thunderstorm was -67.0ºC at 0520 UTC (with the northern pyroCb storm, closer to the fire complex, reaching -66.9ºC at 0500 UTC).  According to 00 UTC rawinsonde data from nearby Williamtown (below), those BTs were 2-3ºC colder than the coded tropopause temp of -64.5ºC at 12.6 km. The VIIRS 11.45 µm BTs were nearly 10ºC colder than the tropopause, suggesting significant penetration of overshooting tops into the lower stratosphere.
Plot of rawinsonde data from Williamtown, New South Wales [click to enlarge]

Plot of rawinsonde data from Williamtown, New South Wales [click to enlarge]

Medicane Trudy

November 11th, 2019 |

EUMETSAT Meteosat-11 Visible (0.8 µm) images, with hourly plots of surface reports [click to play animation | MP4]

EUMETSAT Meteosat-11 Visible (0.8 µm) images, with hourly plots of surface reports [click to play animation | MP4]

EUMETSAT Meteosat-11 Visible (0.8 µm) images (above) showed the circulation and eye-like feature of Medicane “Trudy” (named “DETLEF” by Free University Berlin) as it moved southeastward across the Mediterranean Sea toward the coast of Algeria on 11 November 2019.

VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP (as visualized using RealEarth) are shown below.

VIIRS True Color RGB and Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP [click to enlarge]

VIIRS True Color RGB and Infrared Window (11.45 µm) images from NOAA-20 and Suomi NPP [click to enlarge] 

At 0630 UTC, a northerly wind gust of 52 knots was recorded at Menorca, Spain (LEMH) as the medicane passed near the Balearic Islands — and several hours later as the system moved inland just after sunset, a northwesterly wind gust of 43 knots occurred at Jijel, Algeria (DAAV) at 18 UTC (below).

Time series of surface observation data from Menorca, Spain [click to enlarge]

Time series of surface observation data from Menorca, Spain [click to enlarge]

Time series of surface observation data from Jijel, Algeria [click to enlarge]

Time series of surface observation data from Jijel, Algeria [click to enlarge]

Bush fires in eastern Australia

November 8th, 2019 |

JMA Himawari-8 “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and Longwave Infrared Window (10.4 µm) imagery (below) showed the evolution of smoke plumes, hot 3.9 µm fire thermal anomalies (red pixels) and cloud-top infrared brightness temperatures of isolated pyrocumulus associated with bush fires that were burning in far eastern parts of New South Wales and Queensland, Australia from 1900 UTC on 07 November to 0800 UTC on 08 November 2019. With strong northwesterly surface winds, many of the fire thermal anomalies exhibited rapid southeastward runs toward the coast. That region of Australia had just experienced severe to record 3-month rainfall deficiencies — which included the driest October on record for the southern third of the country.

Himawari-8

Himawari-8 “Red” Visible (0.64 µm) images, with hourly plots of surface reports [click to play animation | MP4]

Himawari-8 Shortwave Infrared (3.9 µm) images, with hourly plots of surface reports [click to play animation | MP4]

Himawari-8 Shortwave Infrared (3.9 µm) images, with hourly plots of surface reports [click to play animation | MP4]

Himawari-8 Longwave Infrared Window (10.4 µm) images, with hourly plots of surface reports [click to play animation | MP4]

Himawari-8 Longwave Infrared Window (10.4 µm) images, with hourly plots of surface reports [click to play animation | MP4]

Himawari-8 True Color Red-Green-Blue (RGB) images created using McIDAS-V (below) provided another view of the dense smoke plumes from 0000-0610 UTC. Toward the end of the animation — in the upper left portion of the satellite scene — plumes of blowing dust could be seen moving eastward from farther inland.

Himawari-8 True Color RGB images (credit: Bob Carp, SSEC) [click to play animation | MP4]

Himawari-8 True Color RGB images (credit: Bob Carp, SSEC) [click to play animation | MP4]

A combination of Suomi NPP VIIRS True Color RGB and Shortwave Infrared (4.1 µm) imagery at 0328 UTC (below) revealed hot thermal signatures of the fires (yellow to red enhancement) at the source of the smoke plumes.

Suomi NPP VIIRS True Color RGB + Shortwave Infrared (4.1 µm) imagery at 0328 UTC [click to enlarge]

Suomi NPP VIIRS True Color RGB + Shortwave Infrared (4.1 µm) imagery at 0328 UTC (credit: Bob Carp, SSEC) [click to enlarge]

A toggle between a Suomi NPP VIIRS True Color RGB image and a display of Sentinel-5 TROPOMI Tropospheric Vertical Column NO2 (below) indicated high NO2 concentrations immediately downwind of these fires.

Suomi NPP VIIRS True Color RGB image + TROPOMI Tropospheric Vertical Column NO2 [click to enlarge]

Suomi NPP VIIRS True Color RGB image + Sentinel-5 TROPOMI Tropospheric Vertical Column NO2 (credit: Bob Carp, SSEC) [click to enlarge]

The dense smoke plumes were also evident in a sequence of 3 VIIRS True Color RGB images from NOAA-20 and Suomi NPP, as visualized using RealEarth (below).

NOAA-20 and Suomi NPP VIIRS True Color RGB images [click to enlarge]

VIIRS True Color RGB images from NOAA-20 and Suomi NPP [click to enlarge]

Smoke reduced the surface visibility to 3 miles or less at Grafton (YGFN) from 03-05 UTC (below).

Time series of surface report data from Grafton, New South Wales [click to enlarge]

Time series of surface report data from Grafton, New South Wales [click to enlarge]