Pyrocumulonimbus cloud in Bolivia

August 18th, 2019 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, top), Shortwave Infrared (3.9 µm, middle) and “Clean” Infrared Window (10.35 µm, bottom) images [click to play animation | MP4]

GOES-16 (GOES-East) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed the formation of a pyrocumulonimbus (pyroCb) cloud over far southeastern Bolivia on 18 August 2019. The small anvil cloud briefly surpassed the -40ºC pyroCb threshold from 1800-1820 UTC, attaining a minimum cloud-top infrared brightness temperature of -45.2ºC along the Bolivia/Paraguay border at 1800 UTC. This pyroCb formed over the hottest southern portion of an elongated fire line, as seen in the Shortwave Infrared imagery.

A 1.5-day animation of GOES-16 Shortwave Infrared images (from 12 UTC on 17 August to 2350 UTC on 18 August) revealed the rapid southeastward run of the fire to the Bolivia/Paraguay border on 17 August, followed by the eastward expansion of the fire line on 18 August (below).

GOES-16 Shortwave Infrared (3.9 µm) images [click to play animation | MP4]

GOES-16 Shortwave Infrared (3.9 µm) images [click to play animation | MP4]

A toggle between Suomi NPP VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 µm) images as viewed using RealEarth (below) showed the large and dense smoke plume streaming southeastward, with the small pyroCb along the Bolivia/Paraguay border at 1745 UTC — the brighter white tops of the pyrocumulus and pyrocumulonimbus clouds reached higher altitudes than the tan-colored smoke plume. The coldest cloud-top infrared brightness temperature was about -55ºC (orange enhancement), which corresponded to an altitude around 9 km according to rawinsonde data from Corumbá, Bolivia.

Suomi NPP VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 µm) images [click to enlarge]

Suomi NPP VIIRS True Color Red-Green-Blue (RGB) and Infrared Window (11.45 µm) images [click to enlarge]


Strong northerly to northwesterly surface winds were blowing across the region, in advance of an approaching cold front (surface analyses) — at Robore, Bolivia (located just north-northwest of the fires), winds were gusting to 25-28 knots during much of the day (below).

Time series of surface report data from Robore, Bolivia [click to enlarge]

Time series of surface report data from Robore, Bolivia [click to enlarge]

This is likely the second confirmed case of a South American pyroCb (the first being on 29 January 2018) — in addition, it’s the second pyroCb documented in the tropics and the first pyroCb documented during a winter season. Thanks to Mike Fromm (NRL) for bringing this case to our attention!

Largest hailstone on record for the state of Colorado

August 13th, 2019 |

GOES-16

GOES-16 “Red” Visible (0.64 µm, left) and “Clean” Infrared Window (10.35 µm, right) images, with plots of SPC Storm Reports [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (above) displayed the increasing coverage of thunderstorms along the Colorado/Kansas border on 13 August 2019, These thunderstorms produced a few tornadoes and large hail — including hail of 5.00 inches in diameter at 2135 UTC near Bethune in extreme eastern Colorado (SPC storm reports).

 

A toggle between NOAA-20 VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images (below) showed the storms at 2022 UTC — just over an hour before the 5.00-inch hail report at 2135 UTC. Note that the NOAA-20 images are incorrectly labelled as Suomi NPP.

NOAA-20 Visible (0.64 µm) and Infrared Window (11.45 µm) images, with NUCAPS sounding locations and surface reports [click to enlarge]

NOAA-20 VIIRS Visible (0.64 µm) and Infrared Window (11.45 µm) images, with NUCAPS sounding locations and surface reports [click to enlarge]

The NOAA-20 NUCAPS profile for the green dot in far western Kansas (below) showed that the airmass in advance of the approaching thunderstorms was very unstable, with a Most Unstable parcel Convective Available Potential Energy (MU CAPE) value of 2737 J/kg and a Lifted Index (LI) value of -10ºC (with no Convective Inhibition CINH).

NOAA-20 NUCAPS profile in far western Kansas [click to enlarge

NOAA-20 NUCAPS profile in far western Kansas [click to enlarge]

In contrast, the NUCAPS profile for the green dot in eastern Colorado (below) revealed an airmass that was less unstable in the wake of the departing thunderstorms.

NOAA-20 NUCAPS profile in eastern Colorado [click to enlarge]

NOAA-20 NUCAPS profile in eastern Colorado [click to enlarge]

===== 14 August Update =====

NWS Goodland Public Information Statement.

 

 

Super Typhoon Lekima in the West Pacific Ocean

August 8th, 2019 |

Himawari-8

Himawari-8 “Red” Visible (0.64 µm, left) and “Clean” Infrared Window (10.4 µm, right) images [click to play animation | MP4]

JMA 2.5-minute rapid scan Himawari-8 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.4 µm) images (above) showed the eye and eyewall region of Category 4 Super Typhoon Lekima on 07-08 August 2019. Features of interest included surface mesovortices within the eye, eyewall cloud-top gravity waves, and a quasi-stationary “cloud cliff” notch extending northwestward from the eye (infrared brightness temperature contours). This cloud cliff feature has been observed with other intense tropical cyclones (for example, Typhoon Neoguri in 2014).

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.

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 trochoidal motion (or wobble) of the eye of Lekima became very pronounced as it crossed the Ryukyu Islands, as seen in an animation of 2.5-minute rapid scan Himawari-8  Infrared images (below). The center of the tropical cyclone moved between Miyakojima (ROMY) and Ishigakijima (ROIG), which reported wind gusts to 67 knots and 64 knots respectively.

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

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

Himawari-8 Infrared images with contours and streamlines of deep-layer wind shear at 15 UTC from the CIMSS Tropical Cyclones site (below) indicated that Lekima was moving through an environment of very low shear, which was a factor aiding its intensification.

Himawari-8 "Clean" Infrared Window (10.4 µm) images, with contours and streamlines of deep-layer wind shear at 15 UTC [click to play animation]

Himawari-8 “Clean” Infrared Window (10.4 µm) images, with contours and streamlines of deep-layer wind shear at 15 UTC [click to play animation]

Natural gas line explosion and fire in Kentucky

August 1st, 2019 |

GOES-16 Fire Temperature (top left), Fire Power (top right), Fire Area (bottom left) and Shortwave Infrared (3.9 µm, bottom right) [click to play animation | MP4]

GOES-16 Fire Temperature (top left), Fire Power (top right), Fire Area (bottom left) and Shortwave Infrared (3.9 µm, bottom right) [click to play animation | MP4]

An explosion and fire along a natural gas pipeline occurred between Junction City and Moreland in central Kentucky on 01 August 2019 (media story 1 | media story 2). GOES-16 (GOES-East) Fire Temperature, Fire Power, Fire Area and Shortwave Infrared (3.9 µm) images (above) showed the thermal signature of the fire — the Fire Temperature peak of 2438.8 K occurred at 0536 UTC, with the maximum Fire Power of 1102.8 MW and the highest 3.9 µm brightness temperature of 103.6ºC occurring at 0526 UTC. More information on these GOES Fire Detection and Characterization Algorithm (FDCA) products can be found here.

In a corresponding comparison of GOES-16 “Red” Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm), Near-Infrared “Cloud Particle Size” (2.24 µm) and Shortwave Infrared (3.9 µm) images (below), thermal signatures were also seen in the Near-Infrared imagery — and a dim signature of this nighttime fire was even apparent in the Visible imagery! The surface observations from Danville Stuart Powell Field Airport are plotted in yellow; the winds were light, minimizing smoke dispersion — but note that the visibility briefly dropped from 10 miles to 7 miles at 07 UTC (possibly due to some smoke drifting over the airport). 

GOES-16 "Red" Visible (0.64 µm, top left), Near-Infrared "Snow/Ice" (1.61 µm, top right), Near-Infrared "Cloud Particle Size" (2.24 µm, bottom left) and Shortwave Infrared (3.9 µm, bottom right) [click to play animation | MP4]

GOES-16 “Red” Visible (0.64 µm, top left), Near-Infrared “Snow/Ice” (1.61 µm, top right), Near-Infrared “Cloud Particle Size” (2.24 µm, bottom left) and Shortwave Infrared (3.9 µm, bottom right) [click to play animation | MP4]

In a comparison of the 4-panel image sets at 0526 UTC (below), the higher spatial resolution of the 0.64 µm (0.5 km*) and 1.61 µm (1 km*) images helped to refine the actual location of the fire. [*at satellite sub-point]

GOES-16 4-panel images at 0526 UTC [click to enlarge]

GOES-16 4-panel images at 0526 UTC [click to enlarge]

With the higher spatial resolution of Suomi NPP VIIRS  and Aqua MODIS Shortwave Infrared imagery, the size and location of the fire’s thermal signature was more accurate when compared to GOES-16 (below). For example, even during the later stage of the fire at 0737 UTC, the VIIRS Shortwave Infrared brightness temperature was 32.0ºC, compared to only 17.9ºC with GOES-16.

Suomi NPP VIIRS Shortwave Infrared (3.74 µm, top left), GOES-16 Shortwave Infrared (3.9 µm, top right), Aqua MODIS Shortwave Infrared (3.7 µm, bottom left) and GOES-16 Shortwave Infrared (3.9 µm, bottom right) images [click to enlarge]

Suomi NPP VIIRS Shortwave Infrared (3.74 µm, top left), GOES-16 Shortwave Infrared (3.9 µm, top right), Aqua MODIS Shortwave Infrared (3.7 µm, bottom left) and GOES-16 Shortwave Infrared (3.9 µm, bottom right) images [click to enlarge]

The bright glow of the fire was also evident in a Suomi NPP VIIRS Day/Night Band (0.7 µm) image at 0651 UTC (below).

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images [click to enlarge]

Suomi NPP VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images, with city names and highways  [click to enlarge]

A thermal signature of the fire (darker red to black pixels) was also seen in GOES-14 Shortwave Infrared (3.9 µm) images (below).

GOES-14 Shortwave Infrared (3.9 µm) images [click to enlarge]

GOES-14 Shortwave Infrared (3.9 µm) images [click to enlarge]