GOES-16 (GOES-East) “Snow/Cloud Discrimination” Red-Green-Blue (RGB) images (above) revealed a west-to-east oriented band of fresh snow cover (1-4 inches, shades of red) across central Illinois on 15 March 2020. With a low-level northeasterly flow of cold air across the region, boundary layer cumulus clouds began to develop as solar heating warmed the surface — but this cloud development was suppressed over deeper portions of the snow cover. These RGB images use “Red” Visible (0.64 µm) data as the Red component, and Near-Infrared “Snow/Ice” (1.61 µm) data as the Green and Blue components; bare ground appears as shades of cyan, with supercooled water droplet clouds appearing as brighter shades of white.

A sequence of VIIRS Snow/Cloud Discrimination RGB images from NOAA-20 and Suomi NPP (below) showed a closer look at the band of snow cover and its effect on modulating the afternoon development of cumulus clouds.

A 30-meter resolution Landsat-8 False Color RGB image viewed using RealEarth (below) provided a detailed view of the band of snow cover (shades of cyan) at 1622 UTC.

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A sequence of GOES-16 (GOES-East) Low-level (7.3 µm), Mid-level (6.9 µm) and Upper-level (6.2 µm) Water Vapor images (above) revealed a subtle wave propagating westward — against the ambient flow within the mid/upper-tropospherc (500 hPa | 300 hPa) — across far eastern Georgia during the afternoon and evening hours on 14 March 2020. There was a “back door cold front” (surface analysis) moving inland from the coast — so this was likely a vertically-propagating frontal gravity wave, similar to those occasionally seen lee of the Rocky Mountains. Although they are less common in this region, another cold frontal gravity wave was observed along the East Coast in April 2008.

Plots of GOES-16 Water Vapor weighting functions calculated using rawinsonde data from Charleston, South Carolina, Jacksonvlle, Florida and Peachtree City, Georgia are shown below. With abundant moisture aloft, much of the sensed radiation was from middle to upper troposphere — giving an indication of the depth of these vertically-propagating frontal gravity waves..

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Even though the South Sandwich Islands are near the limb of the GOES-16 (GOES-East) view, Near-Infrared “Cloud Particle Size” (2.24 µm) images (above) were able to display a long volcanic plume (brighter shades of white) originating from Mount Michael on Saunders Island during the daylight hours on 12 March 2020. In addition, smaller/shorter volcanic plumes could also be seen originating from a few of the smaller islands just to the north of Saunders Island. The volcanic plumes were more reflective (brighter white) because they were comprised of smaller droplets compared to the expansive stratus/stratocumulus clouds over the South Atlantic Ocean.

The smaller cloud particles of the volcanic plume were also more efficient reflectors of incoming solar radiation, thus appearing warmer (darker shades of gray) in GOES-16 Shortwave Infrared (3.9 µm) images (below).

2 days later, southerly/southwesterly winds interacting with the rugged terrain of the islands created von Kármán vortex streets downwind (north-northeast) of some of the islands (especially Montagu Island, the largest of the South Sandwich chain) — VIIRS True Color Red-Green-Blue (RGB) images from NOAA-20 and Suomi NPP  as visualized using RealEarth (below) provided a detailed view of these vortices.

In spite of the lower spatial resolution and large satellite viewing angle, the von Karman vortices could also be seen in GOES-16 “Red” Visible (0.64 µm) images (below).

 

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1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and Shortwave Infrared (3.9 µm) images along with 5-minute Fire Power and Fire Temperature products (which are components of the GOES Fire Detection and Characterization Algorithm (SHyMet | ATBD) showed the rapid northeastward run (as fast as 103 feet per minute) of the 13,000 acre “Beaver Fire” (also known as the “412 Fire”) in the Oklahoma Panhandle on 07 March 2020. An elevated thermal signature on Shortwave Infrared imagery first began to appear southwest of Beaver, OK around 1546 UTC  — and 3.9 µm infrared brightness temperatures eventually peaked around 139ºC. Maximum Fire Power and Fire Temperature values exceeded 3100 MW and 2900 K, respectively. Fire Warnings were issued, with residents of Beaver and Forgan being advised to evacuate as the fire rapidly approached. In Visible imagery, the dark signature of a long, narrow vegetation burn scar was evident — and pyrocumulus clouds were seen developing over the fire.

@NWSDodgeCity @NWSAmarillo photos taken at 4:49 4:53 and 4:55 PM about 4 miles N of the KS-OK State line. Best view of the pyroCu I’ve had. pic.twitter.com/j2nQyGqd6a

— C W (@wilscale) March 7, 2020

Extreme fire behavior was aided by anomalously-strong winds across the southern Plains. The peak wind gust at Beaver, Oklahoma was 46 mph; south of the fire, surface winds were gusting to 43 mph at Perryton (in far the northern Texas Panhandle), and west of the fire winds gusted to 42 mph at Guymon (in the Oklahoma Panhandle). A large-scale animation of 1-minute GOES-16 Visible images from the AOS site (below) indicated that the smoke plume was transported northeastward across Kansas and eventually moved over south-central Nebraska. Smoke reduced the surface visibility to 6 miles at Dodge City as it moved across southwestern Kansas.

Shortwave Infrared images from MODIS (3.7 µm) and VIIRS (3.74 µm) (below) displayed three snapshots of the 10-15 mile long thermal anomaly (elongated cluster of black pixels) associated with the wildfire.

===== 08 March Update =====

During the subsequent overnight hours, a comparison of NOAA-20 VIIRS Day/Night Band (0.7 µm) and Shortwave Infrared (3.74 µm) images at 0857 UTC or 3:57 am local time (above) revealed the dark southwest-to-northeast oriented burn scar, with isolated small fires still burning along the northwestern periphery of the burn scar. Note: the NOAA-20 images are incorrectly labelled as Suomi NPP.

===== 09 March Update =====

A toggle between a GOES-16 Land Surface Temperature product and the corresponding Visible image (above) showed the fire burn scar at 2101 UTC on 09 March. Land Surface Temperature values were 10ºF warmer within the burn scar (middle 80s F, shades of yellow to orange) compared to areas immediately adjacent to the burn feature.

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