1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Clean” Infrared Window (10.35 µm) images — with and without an overlay of GLM Flash Extent Density — and “Red” Visible (0.64 µm) images (above) showed showed an impressive convective burst near the center of Tropical Storm Delta, which developed a couple of hours before the storm reached Category 1 Hurricane intensity at 0000 UTC on 06 October over the Caribbean Sea. There was no GLM-detected lightning activity near the center of Delta during this 2100-0100 UTC time period.

A toggle between GOES-16 Infrared and Visible images at 2156 UTC (below) revealed a small tropical overshooting top near the center of the developing convective burst — which exhibited a cloud-top infrared brightness temperature as cold as -93.2ºC (yellow pixels embedded within the darker shades of purple).

===== 06 October Update =====

Hurricane Delta rapidly intensified to a Category 4 storm at 1520 UTC on 06 October — with 1-minute GOES-16 Infrared and Visible images (above) showing evidence of a more organized eye and eyewall structure, including a notable amount of lightning activity near the core of the storm.

GOES-16 Infrared Window (11.2 µm) images from the CIMSS Tropical Cyclones site (below) indicated that Delta was moving through an environment of low deep-layer wind shear as the hurricane was moving over water possessing very high ocean heat content.

===== 07 October Update =====

A comparison Suomi NPP VIIRS Infrared Window (11.45 µm) and Day/Night Band (0.7 µm) images (above) revealed a small area with cloud-top infrared brightness temperatures as cold as -100.9ºC (within the small cluster of red pixels) just east of the island of Cozumel, Mexico. Even though Delta was still moving over water possessing very high ocean heat content, its intensity was reduced from Category 4 to Category 3 around this time.

A time-matched comparison of Infrared images from Suomi NPP and GOES-16 is shown below; a cloud-top infrared brightness temperature of -95.8ºC was sensed by GOES-16. There was significant parallax associated with the Suomi NPP image, since Hurricane Delta was located along the far western edge of the descending overpass swath. The same color enhancement is applied to both images.

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1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed Category 4 Hurricane Marie over the East Pacific Ocean on 02 October 2020. Although there was frequently some high cloud debris covering the eye, hints of low-altitude mesosvortices within the eye could be seen at times. The coldest cloud-top infrared brightness temperatures were in the -85 to -88ºC range.

GOES-17 Infrared Window (11.2 µm) images from the CIMSS Tropical Cyclones site (below) indicated that Marie was moving through an environment of relatively low deep-layer wind shear.

===== 03 October Update =====

A toggle between time-matched Infrared Window images of the eye and eyewall region of Hurricane Marie from Suomi NPP (SNPP) and GOES-17 (below) highlighted the differences in spatial resolution — 375-m with SNPP VIIRS, vs 2-km (at satellite sub-point) with GOES-17 ABI — and the parallax displacement inherent with GOES-17 imagery at that location (approximately 9 km to the northeast). The coldest cloud-top infrared brightness temperature was -85.4ºC on the SNPP image, compared to -81.8ºC on the GOES-17 image; small-scale features such as the gravity waves propagating radially outward from the eye were seen in the higher resolution SNPP image. Note: the 0929 UTC time stamp on the SNPP image was the time that the ground station antenna began receiving the descending overpass signal – the satellite actually passed over Marie’s location at 0943 UTC.

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GOES-16 (GOES-East) True Color Red-Green-Blue (RGB) images created using Geo2Grid (above) showed plumes of smoke drifting across parts of Colorado on 30 September 2020. The most smoke prominent plume originated from the Mullen Fire in far southern Wyoming — which produced a pyroCb cloud on 19 September.

On the following morning, the hazy signature of low-altitude smoke that had settled overnight into the North Park and Middle Park plateau areas of north-central Colorado was evident in CIMSS Natural Color RGB images (below). During the morning hours, this smoke restricted the surface visibility to 1-3/4 mile at Walden and 5 miles at Kremmling, before gradually beginning to disperse in the afternoon hours.

The signature of North Park and Middle Park plateau smoke was more vivid using GOES-16 True Color imagery which includes a correction for Rayleigh scattering (below).

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NOAA-20 overflew a mostly clear northern Gulf of Mexico shortly after 1900 UTC on 1 October. Advanced Clear-Sky Processor for Ocean (ACSPO) sea-surface temperatures, shown above, were derived by CSPP (the Community Satellite Processing Package) using Direct Broadcast data at CIMSS (Training for Direct Broadcast data is available here). The AWIPS-ready datafiles are available via an LDM pull to forecast offices.

Near-shore Sea-Surface temperatures have cooled to around 80. The default enhancement used in AWIPS has been narrowed to show temperatures only from 68ºF to 90ºF. Warmer offshore waters are present, but cloudiness over the central Gulf prevented SST detection. The warmest waters in the scene are in Lake Maurepas in Louisiana, and in various bays (Mobile, Perdido, Pensacola). A zoomed-in scene is shown below. Because this product uses the I-Bands on VIIRS, it has extraordinary horizontal resolution.

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