This blog post shows satellite imagery with a Singapore Airlines Boeing 777-300ER that encountered severe turbulence while flying over southern Myanmar (information from flightradar) at 0749 UTC on 21 May 2024. This graphic from Sarah Griffin, CIMSS, shows the turbulence location/time; other graphics/animations from this event are in this directory that Sarah Griffin created.

LightningCast probabilities predict where an (in this case, hypothetical) GLM instrument would detect a lightning flash in the next 60 minutes based on current ABI or AHI imagery at 0.64 µm, 1.61 µm, 10.3 µm and 12.3 µm. Although this machine-learning tool was trained on GOES-East ABI and GLM imagery, it is being applied to the similar AHI instrument that flies on Himawari-9. (Real-time Himawari-9 LightningCast imagery is available at this RealEarth instance under the ‘Guam’ sector). The LightningCast contours shown in this blog post were created using a CSPP Geo software package in development/testing at CIMSS, with a Beta release on the horizon. More than an hour before the turbulence that affected the Boeing 777, LightningCast is suggesting the region is very likely to have lightning. The animation below shows how the LightningCast contours (and satellite imagery) changed between 0630 and 0800 UTC on 21 May. Diagnosed probabilities of lightning remain high over the region throughout the 80-90 minutes prior to the turbulent encounter.

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1-minute Mesoscale Domain Sector GOES-18 (GOES-West) “Red” Visible (0.64 µm) images (above) showed areas of bright sun glint off the open (ice-free) water in the Chukchi Sea — just off the coast of Alaska, from the Bering Strait to near Utqiagvik (formerly Barrow) — around 1 AM local time on 08 June 2024. Note how there was also sun glint off the open water of leads within the sea ice, as well as inland rivers/lakes across northern Alaska.

Synthetic Aperture Radar (SAR) wind speed (source) derived from an overpass of RADARSAT-2 at 0349 UTC on 08 June (below) showed that winds were generally light (or even calm) across the nearshore waters off the northwest coast of Alaska — which would be conducive to a sea surface with minimal wave height (that would more easily reflect incoming late-day sunlight arriving at a very oblique angle, enhancing sun glint).

ASCAT and OSCAT surface scatterometer winds (source) confirmed the presence of light wind speeds over a portion of the open water north of the Bering Strait, where the sun glint was seen (below).

During the subsequent daytime hours, a sequence of VIIRS Snowmelt RGB images sourced from GINA and displayed using RealEarth (below) provided a more detailed view of the sea ice and the areas of inland snow cover (shades of cyan to light blue), in contrast to the areas of open water (dark blue) near the Alaskan coast.

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30-second Mesoscale Domain Sector GOES-16 (GOES-East) images from all 16 of the ABI spectral bands along with a Rocket Plume RGB (above) displayed signatures of a Boeing Starliner’s Atlas V rocket booster that was launched from Cape Canaveral Space Force Station in Florida at 1552 UTC (11:52 AM EST) on 05 June 2024. The warm thermal signature of the rocket booster (moving rapidly to the northeast) and/or the relatively cold rocket condensation cloud (drifting slowly eastward just off the coast) were evident in all of the ABI spectral band images, as well as the Rocket Plume RGB imagery.

A larger-scale view of 30-second GOES-16 Rocket Plume RGB images created using Geo2Grid (below) spans an additional 2 minutes — showing the rocket booster signature extending even farther to the northeast.

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A period of high-based convection to the east and northeast of Hawaii was producing occasional lighting on 3 June 2024, as shown in the animation above. LightningCast Probabilities plotted show values around 50%, and lightning is occurring. Note that the Flash Extent Density colorbar has been modified to have a maximum value of only 8.

The convection is creating a signal in the CIMSS Turbulence product, shown below in imagery from this website. The animation below shows the contours of the probability of Moderate Or Greater (MOG) Turbulence to the northeast of Hawaii. The animation below also shows water vapor imagery as a greyscale, from which you can infer the upper-level low-pressure system over the Hawaiian Islands that is helping to force the thunderstorms.

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NOAA-20 overflew the region at around 1200 UTC on 3 June, and some NUCAPS soundings in the region are shown below. They uniformaly show a moist boundary layer capped by a stable layer. The mid-troposphere above that cap shows steep lapse rates and drying with height, that is, a convectively unstable atmosphere.

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High-based convection again developed between 0600 and 1200 UTC on 4 May 2024. The Hilo Sounding, below (source), showed a capped moist boundary layer with an unstable atmosphere above 700 mb.

NOAA-21 overflew the islands just before 0000 UTC as shown below. The NUCAPS soundings along the north shore of the big island of Hawai’i, are shown below. The profile north of 20 N is from 234344 UTC, the one south of 20 N is from 234312 UTC. The structures of the smooth NUCAPS profiles are similar to those of the Hilo rawinsonde shown above.

The animation below shows the LightningCast output (from this website) for the elevated convection between 0600 and 0800 UTC on 4 June 2024.

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Thanks to Robert Ballard, Science and Operations Officer (SOO) at WFO Honolulu for alerting us to this event. He notes the similarity to an event back in the year 2000, mentioned in this AFD. High-based thunderstorms such as these are rare in the tropics. They are decoupled from the tradewind cumulus: the thunderstorms are moving northward as the lower clouds move towards the west.

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