GOES-16 (GOES-East) Shortwave Infrared (3.9 µm) images (above) showed the diurnal variability of thermal anomalies (hot pixels) associated with a cluster of wildfires in southern Quebec during the 02 June – 04 June 2023 period. On the first of these 3 days, several of the wind-driven fires exhibited 3.9 µm brightness temperatures of 137.71ºC (the saturation temperature of the GOES-16 ABI Band 7 detectors).

The GOES-16 Fire Power derived product during that same 3-day period is shown below — the hottest fires exhibited Fire Power values as high as 3600 MW. The Fire Power derived product is a component of the GOES Fire Detection and Characterization Algorithm (FDCA).

In a larger-scale view of GOES-16 True Color RGB images and Nighttime Microphysics RGB images from the CSPP GeoSphere site (below), dense wildfire smoke plumes (along with their long-range transport paths over parts of the northern US) were evident during the daytime hours, while the fire thermal anomalies (darker shades of purple) were apparent at night.

===== 05 June Update =====

On 05 June, GOES-16 Shortwave Infrared, “Red” Visible (0.64 µm), “Clean” Infrared Window (10.3 µm) and Cloud Top Temperature (CTT) derived product images (above) revealed that 2 of the Quebec wildfires north and northeast of Chibougamau-Chapais (CYMT) produced pyrocumulonimbus (pyroCb) clouds late in the day, which exhibited anvil 10.3 µm brightness temperature and/or CTT values of -40ºC and colder (shades of blue).

GOES-16 Visible images combined with the Fire Power derived product (below) include an overlay of GLM Flash Extent Density — which showed that some lightning activity was associated with these pyroCb clouds. In fact, shortly after sunset a thunderstorm was reported in the vicinity of CYMT as the pyroCb cloud drifted just east of the site at 0200 UTC. In addition, smoke from the nearby pyroCb-producing wildfire briefly reduced the surface visibility to 2-1/4 miles at CYMT (plot of surface observations).

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NASA Worldview imagery of Terra (launched in 1999 and still producing imagery!) MODIS true-color imagery, above, from this link, shows an ellipsoidal feature to the southeast of Guam with cloud development along its southern flank. Terra was passing west of Guam at about 0045 UTC on 20 May 2023, with the rising sun in the eastern sky (Terra orbits for that day over the western Pacific are here, taken from this site). Sunglint in visible imagery is caused by reflection of solar energy off the ocean’s surface; the concentration — brightness — of the sunglint is related to the ocean state. If the ocean surface is completely flat, reflection would be in one region that would be very bright, and the surrounding ocean where winds are light would be dark. Beyond the region of light winds, the sea would appear bright. Thus, changes in the sunglint apparent above are likely related to changes in the windspeed over the ocean in the region.

Cloud debris exists near the center of this ellipse, and it’s reasonable to assume this is a dying convective feature, and that the ellipse outlines the outward-propagating downdraft. The animation of Himawari Clean Window infrared (Band 13, 10.4 µm) and visible imagery (Band 3, 0.64 µm), below, from 0010 to 0100 UTC on 20 May, shows motion cloud features consistent with that theory.

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1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.3 µm) images (above) showed Tropical Depression Two as it developed over the northern Gulf of Mexico on 01 June 2023. The low-level circulation center became exposed late in the day, as deep convection remained focused to the northeast of the disturbance center — cloud-top infrared brightness temperatures of the thunderstorm overshooting top pulses were as cold as -65ºC at 2322 UTC (below).

Although TD Two was forecast to move southward across warmer water associated with the Gulf of Mexico Loop Current (Sea Surface Temperature | Ocean Heat Content), modest amounts of deep-layer wind shear from the CIMSS Tropical Cyclones site (below) did not favor a large amount of intensification.

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1-minute Mesoscale Domain Sector GOES-18 (GOES-West) “Clean” Infrared Window (10.3 µm) images (above) are shown with and without an overlay of GLM Flash Extent Density and contours of Lightning Cast Probability from 1530-1915 UTC on 01 June 2023 — the time period covering outdoor graduation ceremonies at the Air Force Academy in eastern Colorado. LightningCast provided good lead time, with Probability values over the Air Force Academy first reaching 75% at 1619 UTC — the first pixel of Flash Extent Density (FED) over the Academy location was at 1815 UTC (with FED becoming more frequent and widespread over that area after 1851 UTC).

Air Force Academy Graduation

Thunderbirds and lightning!

Thanks to Vicki Rusinak Caldwell for sending this to me! #COwx #Lightning #AFA pic.twitter.com/QjPLyAvw1b

— Kody Wilson (@kodythewxguy) June 1, 2023

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