ProbSevere LightningCast Probabilities for Guam

September 15th, 2022 |
RealEarth display of Himawari-8 Band 13 (10.4 µm) infrared imagery and LightningCast Probability contours, 1320 – 1420 UTC on 15 September 2022 (Click to enlarge)

At the request of the National Weather Service forecast office in Guam (where the National Weather Service’s day begins), CIMSS is computing a small region of LightningCast Probabilities that uses Himawari-8 data. The Guam forecast office issues a lightning ‘advisory’ if lightning is possible or occurring within 20 mi of the Guam Airport, and a lightning ‘warning’ if lightning is possible/occurring within 5 mi of the airport. LightningCast probabilities will help in this task. Forecasters will be evaluating its performance in the coming weeks.

LightningCast imagery is available in a RealEarth instance here (at that website, there is a small drop-down menu titled ‘Select Sector’; Choose Guam). An example animation is shown above. (Guam is located at the outer fringes of Typhoon Nanmadol in the image) In contrast to the scenes under GOES-East’s and GOES-West’s view, GLM data are not available. In the forecast office, ground-based lightning sources are available. This animation (from John Cintineo, CIMSS) shows LightningCast probabilities with Earth Networks Total Lightning. Animations online, as shown above, show only Himawari-8 data and LightningCast probability contours.

As with GOES-R LightningCast computations, Himawari-8 uses Visible (0.64 µm), near-infrared (1.61 µm) and infrared (10.41 µm and 12.3 µm) observations. Resolution differences at 1.61 µm (1 km for GOES-R and 2 km for Himawari-8) and slight differences in infrared spectral responses, especially for band 13 (centered near 10.33 µm for GOES-R and 10.41 µm for Himawari-8) may have an as-yet unknown impact on LightningCast probabilities.

Super Typhoon Hinnamnor once again reaches Category 5 intensity

August 31st, 2022 |

JMA Himawari-8 Visible (0.64 µm) images [click to play animated GIF | MP4]

2.5-minute rapid scan JMA Himawari-8 Visible (0.64 µm) images (above) showed rapidly-intensifying Typhoon Hinnamnor as it once again reached Category 5 intensity (ADT | AiDT | SATCON) about 3 hours after local sunrise on 31 August 2022. Mesovortices rotating within the eye were evident though breaks in patchy high clouds overhead.

2.5-minute Himawari-8 Infrared (10.4 µm) images (below) revealed convection within the eyewall region which exhibited cloud-top infrared brightness temperatures of -80°C and colder (violet pixels).

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

Several hours before sunrise, a toggle between NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images valid at 1749 UTC, viewed using RealEarth (below) revealed concentric mesospheric airglow waves in the DNB image, propagating away from Hinnamnor (primarily to the north of the storm).

NOAA-20 VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images, valid at 1749 UTC [click to enlarge]

The mesospheric airglow waves were less evident in an earlier comparison of Suomi-NPP VIIRS Day/Night Band and Infrared Window images, valid at 1700 UTC (below) — however, at that time the DNB displayed bright streaks near the eye, indicative of clouds illuminated intense lightning activity.

Suomi-NPP VIIRS Day/Night Band (0.7 µm) and Infrared Window (11.45 µm) images, valid at 1700 UTC [click to enlarge]

Super Typhoon Hinnamnor in the West Pacific

August 29th, 2022 |

JMA Himawari-8 Visible (0.64 µm) images [click to play animated GIF | MP4]

2.5-minute rapid scan JMA Himawari-8 Visible (0.64 µm) images (above) showed rapidly-intensifying Category 4 Typhoon Hinnamnor as it moved across the West Pacific Ocean (southeast of Japan) on 29 August 2022. Mesovortices within the eye were faintly evident though breaks in patchy high clouds overhead.

2.5-minute Himawari-8 Infrared (10.4 µm) images (below) revealed a few pulses  of convection which exhibited cloud-top infrared brightness temperatures of -80°C and colder (violet pixels).

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

A DMSP-17 SSMIS Microwave (85 GHz) image at 2142 UTC from the CIMSS Tropical Cycones site (below) also depicted the well-defined eye and eyewall structure.

DMSP-17 SSMIS Microwave (85 GHz) image at 2142 UTC [click to enlarge]

===== 30 August Update =====

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

On the following day, Himawari-8 Infrared (10.4 µm) images (above) showed the well-defined eye and surrounding eyewall as Hinnamnor reached Category 5 intensity at 1200 UTC. An eyewalll replacement cycle began around 2100 UTC, leading to a slight decline in intensity (to Category 4) and a deteriorating eye structure.

Post-sunrise Himawari-8 Visible (0.64 µm) images (below) better showed how close the eye passed to the Japanese islands of Kitadait?jima (RORK, where winds gusted to 98 knots) and Minamidait?jima (ROMD, where winds gusted to 69 knots).

JMA Himawari-8 Visible (0.64 µm) images [click to play animated GIF | MP4]

In a toggle between nighttime Suomi-NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images valid at 1717 UTC, viewed using RealEarth (below), the Day/Night Band image displayed a bright lightning streak just southwest of the eye — showing clouds within the eyewall being illuminated by intense lightning activity; cloud-top gravity waves were evident southeast of the eye in the Infrared image.

Suomi-NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images valid at 1717 UTC [click to enlarge]

Grassland fire in North Dakota

August 21st, 2022 |

GOES-16 Fire Temperature RGB images [click to play animated GIF | MP4]

GOES-16 (GOES-East) Fire Tempera ture RGB images (above) showed the rapid north-northwestward spread of a wind-driven grassland fire across Sioux County in far southern North Dakota during the early afternoon hours on 21 August 2022. South-southeasterly winds were gusting to 17-18 knots (19-21 mph) at surrounding METAR sites during that time period.

The GOES-16 Fire Temperature RGB image at 1921 UTC (below) includes cursor readouts of the individual RGB components, along with the corresponding Fire Detection and Characterization Algorithm (FDCA) products. This was the time of the peak 3.9 µm infrared brightness temperature of 86.95ºC — the FDCA Fire Temperature value was 758.57 K, while the Fire Power was 912.46 MW.

GOES-16 Fire Temperature RGB image at 1921 UTC, with cursor readouts of RGB components and Fire Detection and Characterization Algorithm products [click to enlarge]

In Suomi-NPP VIIRS True Color and False Color RGB images valid at 1938 UTC viewed using RealEarth (below), the elongated dark vegetation burn scar was evident, along with a smoke plume fanning out to the north and a lone pyrocumulus cloud just northeast of the active fire (brighter shades of pink in the False Color image).

Suomi-NPP VIIRS True Color and False Color RGB images, valid at 1938 UTC [click to enlarge]