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.hunderstorms

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]

Hurricane Erick in the East Pacific Ocean

July 30th, 2019 |

GOES-17

GOES-17 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed the well-defined eye of Hurricane Erick on 30 July 2019. Mesovortices could be seen within the eye on the visible imagery, along with periodic convective bursts within the surrounding eyewall region — and cloud-top infrared brightness temperatures as cold as -84ºC were associated with these convective bursts.

Prior to sunrise Erick experienced a period of rapid intensification, as seen in a Advanced Dvorak Technique plot from the CIMSS Tropical Cyclones site (below). Erick was classified as a Category 4 hurricane as of the 18 UTC advisory.

Advanced Dvorak Technique (ADT) plot for Hurricane Erick [click to enlarge]

Advanced Dvorak Technique (ADT) plot for Hurricane Erick [click to enlarge]

Around the time that the period of rapid intensification was beginning, a NOAA-20 VIIRS Infrared Window (11.45 µm) image viewed using RealEarth (below) revealed a distinct eye around 11 UTC.

NOAA-20 VIIRS Infrared Window (11.45 µm) image [click to enlarge]

NOAA-20 VIIRS Infrared Window (11.45 µm) image [click to enlarge]