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]

Canadian wildfire smoke across the Upper Midwest and Great Lakes

July 7th, 2019 |

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 (GOES-East) True Color Red-Green-Blue (RGB) images from the AOS site (above) showed the signature of dense smoke from Canadian wildfires that was being transported southward across parts of the Upper Midwest on 06 July 2019. While much of the smoke remained aloft, some of it was reaching the surface and restricting the visibility at locations such as International Falls, Baudette and Thief River Falls in northern Minnesota and Fargo in eastern North Dakota.

On the following day, the smoke settled farther southward over Wisconsin and Michigan (below). Much of the smoke again remained aloft, but continued to persist within the boundary layer at Baudette and International Falls — and it did briefly restrict the surface visibility at Green Bay in northeastern Wisconsin.

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

===== 08 July Update =====

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

On 08 July the smoke covered much of the Great Lakes and parts of adjacent states (above).

===== 09 July Update =====

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

On 09 July, a gradual decreasing trend in the areal coverage and density of smoke over the Great Lakes was seen (above). A Suomi NPP VIIRS True Color RGB image acquired and processed by the CIMSS/SSEC Direct Broadcast ground station (below) showed that some of the smoke had moved over the Mid-Atlantic states and out across the adjacent offshore waters of the Atlantic Ocean.

Suomi NPP VIIRS True Color RGB image [click to enlarge]

Suomi NPP VIIRS True Color RGB image [click to enlarge]

NUCAPS Profiles are back in AWIPS

July 2nd, 2019 |

1200 UTC Soundings from KGYX (Grey Maine) on 2 July 2019 and 1600 UTC NUCAPS sounding from nearby, showing changes in the thermodynamics (Click to enlarge)

Back in late March 2019, the Cross-track Infrared Sounder (CrIS) suffered an anomaly such that the mid-wave portion of the electromagnetic spectrum (a part that includes channels sensitive to water vapor) was not scanned properly. Thus, NUCAPS soundings created from Suomi-NPP were lost (link). Today, NUCAPS soundings created using NOAA-20 (which has the same instruments as Suomi-NPP) began flowing into AWIPS. Data from shortly after 1500 UTC were the first to appear.

NUCAPS Soundings over the northeastern United States at 1629 UTC on 2 July 2019 (Click to enlarge)

NUCAPS profiles from NOAA-20 are processed somewhat differently than those from Suomi-NPP as far as latency: NOAA-20 NUCAPS profiles show up more quickly — typically within an hour of the observations time — in AWIPS than NPP NUCAPS profiles did. This is important because the thermodynamic information in these mid-afternoon observations is important in judging destabilization relative to morning soundings.

When Suomi NPP was launched, two independent sets of electronics were present on CrIS; the ‘A’-side set of electronics were used until March; the ‘B’-side electronics have been used since June, and mid-wave observations from Suomi-NPP’s CrIS are now available at this site. However, NUCAPS soundings are not yet being created from Suomi-NPP because the A-side and B-side electronics have different statistical behavior that must be accounted for in the Regression used to start the NUCAPS processing.