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).

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.

Plots of coldest Himawari-8 10.4 µm brightness temperatures on 2.5-minute Target Sector (blue) and 10-minute Full Disk (green) images [click to enlarge]

Plots of coldest Himawari-8 infrared (10.4 µm) brightness temperatures on 2.5-minute Target Sector (blue) and 10-minute Full Disk (green) images [click to enlarge]

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). 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 9 Target Sector and 4 Full Disk images.

 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]

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).

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]

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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]

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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 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.

Visible (0.64 µm) Imagery from Himawari-8 (left) and GK2A (right) from 2100 UTC on 29 November to 0820 UTC on 30 November 2019 (Click to animate)

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.

KMA GK2A Cloud Top Temperature product [click to play animation | MP4]

KMA GK2A Cloud Top Temperature product [click to play animation | MP4]

KMA GK2A Cloud Top Height product [click to play animation | MP4]

KMA GK2A Cloud Top Height product [click to play animation | MP4]

Bomb cyclone makes landfall along the Oregon/California coast

November 26th, 2019 |

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images, with 3-hourly plots of surface fronts [click to play animation | MP4]

GOES-17 Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images, with surface fronts plotted in cyan and buoy locations plotted in red [click to play animation | MP4]

A sequence of GOES-17 (GOES-West) Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images (above) showed the evolution of a bomb cyclone (surface analyses: WPC | OPC) that made landfall along the Oregon/California coast just after sunset on 26 November 2019. The storm produced wind gusts of 106 mph in southwestern Oregon and 70 mph in northwestern California.

GOES-17 “Red” Visible (0.64 µm) images of the storm are shown below — the Mean Sea Level Pressure anomaly was 4-5 sigma below the climatological mean as the rapidly-deepening midlatitude cyclone made landfall. Similarly, 925 hPa wind speed anomaly was 3-5 sigma above the climatological mean. The system had transitioned to a warm seclusion phase by 00 UTC, as seen in a comparison of Visible and Water Vapor images at that time.

GOES-17 "Red" Visible (0.64 µm) images, with 3-hourly plots of surface fronts [click to play animation | MP4]

GOES-17 “Red” Visible (0.64 µm) images, with surface fronts plotted in cyan and buoy locations plotted in red [click to play animation | MP4]

A GOES-17 Mesoscale Domain Sector was positioned over the region, providing Visible images at 1-minute intervals (below).

GOES-17

GOES-17 “Red” Visible (0.64 µm) images, with hourly plots of surface wind barbs and gusts in knots [click to play animation | MP4]

A larger-scale view of the entire GOES-17 Mesoscale Domain Sector is shown below, using Visible images from the AOS site.

GOES-17 "Red" Visible (0.64 µm) images [click to play animation | MP4]

GOES-17 “Red” Visible (0.64 µm) images [click to play animation | MP4]

1-km resolution NOAA-15 AVHRR Shortwave Infrared (3.7 µm) imagery at 0217 UTC (below) showed the center of circulation just off the Oregon/California coast. At that time, winds were gusting to 50 knots at Crescent City, California (KCEC).

NOAA-15 AVHRR Shortwave Infrared (3.7 µm) image at 0217 UTC [click to enlarge]

NOAA-15 AVHRR Shortwave Infrared (3.7 µm) image at 0217 UTC, with plots of 02 UTC surface reports (cyan/yellow) and wind gusts (in knots, red) [click to enlarge]

A time series of surface data from Crescent City, California (below) showed the period when the air pressure dropped to 973.4 hPa (28.74 inches) — setting a new all-time low pressure record for the state of California. In addition, new low pressure records for the month of November were set at Medford, Oregon (981.4 hPa / 28.98 inches) and at Eureka, California (984.8 hPa / 29.08 inches).

Time series of surface data at Crescent City, California [click to enlarge]

Time series of surface data at Crescent City, California [click to enlarge]

Air pressure at the offshore buoy 8 miles NW of Crescent City (46027) dropped to 971.7 hPa (28.69 inches) at 0350 UTC (below).

Plots of Wind Speed (blue), Wind Gust (red) and Air Pressure (green) from Buoy 46027

Plots of Wind Speed (blue), Wind Gust (red) and Air Pressure (green) from Buoy 46027


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]

Widespread fires across the Deep South

November 19th, 2019 |

GOES-16 Fire Temperature RGB, Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area products [click to play animation | MP4]

GOES-16 Fire Temperature RGB, Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area products [click to play animation | MP4]

A sequence of GOES-16 (GOES-East) Fire Temperature RGB, Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area products (above) displayed signatures of widespread fires — a combination of prescribed burns and agricultural fires — across parts of the Deep South on 19 November 2019. Fire Temperature, Fire Power and Fire Area products are components of the GOES Fire Detection and Characterization Algorithm (SHyMet | ATBD).

GOES-16 “Red” Visible (0.64 µm) images, with and without plots of surface observations, are shown below. While most of the fires were too small/brief to produce large smoke plumes, a prominent plume was associated with one of the hottest and most long-lived fires — which was likely a prescribed burn — in the Chickasawhay State Wildlife Management Area (located east of Hattiesburg/Laurel Airport KPIB) in southeastern Mississippi.

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with and without plots of surface observations [click to play animation | MP4]

There were no surface stations downwind of that Mississippi fire; however, one small smoke plume drifted over Lafayette in southern Louisiana (KLFT) near the end of the day, briefly reducing the visibility to 6 miles at 22 UTC (below).

Time series of surface observation data from Lafayette Regional Airport in Louisiana [click to enlarge]

Time series of surface observation data from Lafayette Regional Airport in Louisiana [click to enlarge]

For the hot fire in southeastern Mississippi, GOES-16 Shortwave Infrared, Fire Temperature, Fire Power and Fire Area values are shown for the same hot fire pixel at 1716, 1731 and 1806 UTC (below). Note that the individual parameter trends can be different for a given fire pixel — for example, even though the hottest 3.9 µm brightness temperature value was 58.8ºC at 1806 UTC, the peak Fire Temperature value was 1373.1 K at 1731 UTC. However, the time of the maximum Fire Power value of 213.6 MW coincided with the time of the hottest 3.9 µm brightness temperature value (1806 UTC).

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1716 UTC [click to enlarge]

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1716 UTC [click to enlarge]

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1731 UTC [click to enlarge]

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1731 UTC [click to enlarge]

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1806 UTC [click to enlarge]

GOES-16 Shortwave Infrared (3.9 µm), Fire Temperature, Fire Power and Fire Area values at 1806 UTC [click to enlarge]