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Saharan Air Layer plume over the Atlantic Ocean

GOES-16 (GOES-East) Split Window images (above) showed a large plume of the Saharan Air Layer (SAL) that moved westward off the coast of Africa then westward and northwestward across the eastern and central Atlantic Ocean during the 15-20 September 2019 period.On 20 September, the hazy SAL plume could be easily seen... Read More

Saharan Air Layer product [click to play animation | MP4]

GOES-16 “Split Window” Saharan Air Layer product [click to play animation | MP4]

GOES-16 (GOES-East) Split Window images (above) showed a large plume of the Saharan Air Layer (SAL) that moved westward off the coast of Africa then westward and northwestward across the eastern and central Atlantic Ocean during the 15-20 September 2019 period.

On 20 September, the hazy SAL plume could be easily seen in Full Disk GOES-16 True Color Red-Green-Blue (RGB) images from the AOS site (below).

GOES-16 True Color images [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

The SAL plume was also apparent in True Color RGB images from Suomi NPP and NOAA-20 as viewed using RealEarth (below).

VIIRS True Color RGB images from Suomi NPP and NOAA-20 [click to enlarge]

A comparison of GOES-16 CIMSS Natural Color RGB, Aerosol Optical Depth and Dust Detection product images from 1500-1900 UTC on 20 September (below) revealed AOD values as high as 0.5 within the hazy dust-laden SAL plume; the Dust Detection product indicated large areas of Low- to Medium-Confidence dust (with isolated pockets of High Confidence).

GOES-16 CIMSS Natural Color RGB, Aerosol Optical Depth, and Dust Detection product [click to play animation | MP4]

GOES-16 CIMSS Natural Color RGB, Aerosol Optical Depth, and Dust Detection product [click to play animation | MP4]


On a side note, the Full Disk True Color shown above images revealed 3 different types of solar backscatter: a small spot of very bright sun glint off the water of the Amazon River and its tributaries, which moved from east to west — similar to this example from October 2018  (below)

GOES-16

GOES-16 “Red” Visible (0.64 µm) images [click to play animation | MP4]

along with 2 separate (and larger) areas of more diffuse solar backscatter, which propagated from west to east: the first (possibly a 180º-42º=138º or “rainbow” backscatter) appeared about midway between the Equator and the southern tip of South America — and the second  (a 180º backscatter) appeared farther north, closer to the Equator, slightly later in time (this type of solar backscatter was previously discussed here). These 3 solar backscatter features can also be seen in a rocking animation below.

GOES-16 True Color RGB images [click to play animation | MP4]

GOES-16 True Color RGB images [click to play animation | MP4]

Thanks to Fred Wu (NOAA/NESDIS) and Steve Miller (CIRA) for providing further insight regarding the nature of the 2 larger types of solar backscatter.

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Snowfall across northern Alaska

GOES-17 (GOES-West) “Red” Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm), Day Snow-Fog Red-Green-Blue (RGB) and and Day Cloud Phase Distinction RGB images (above) showed portions of the Brooks Range and eastern North Slope of Alaska that had significant snow cover on 18 September 2019. Some areas received 4-6 inches of snowfall during the previous day (a... Read More

GOES-17

GOES-17 “Red” Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm), Day Snow-Fog RGB and Day Cloud Phase Distinction RGB images [click to play animation | MP4]

GOES-17 (GOES-West) “Red” Visible (0.64 µm), Near-Infrared “Snow/Ice” (1.61 µm), Day Snow-Fog Red-Green-Blue (RGB) and and Day Cloud Phase Distinction RGB images (above) showed portions of the Brooks Range and eastern North Slope of Alaska that had significant snow cover on 18 September 2019. Some areas received 4-6 inches of snowfall during the previous day (a Winter Storm Warning had been issued, forecasting accumulations in the 4-8 inch range).

Snow cover appeared brighter white in the Visible images, and darker shades of gray in the Snow/Ice images; in the RGB images, snow was darker shades of red in the Day Snow-Fog, vs brighter shades of green in the Day Cloud Phase Distinction. Note that the Day Cloud Phase Distinction RGB provided sharper images than the Day Snow-Fog RGB (below), since the former makes use of higher spatial resolution 0.64 µm data for its Green component.

GOES-17 Day Cloud Phase Distinction RGB and Day Sow-Fog RGB images at 2030 UTC [click to enlarge]

GOES-17 Day Cloud Phase Distinction RGB and Day Sow-Fog RGB images at 2030 UTC [click to enlarge]

Although much of the Bettles (PABT) area was masked by cloudiness on 18 September, that site received moderate to heavy snow for a few hours on 17 September (below), and reported a snow depth of 4 inches at 17 UTC (9 am local time).

Time series of surface data from Bettles, Alaska on 17 September [click to enlarge]

Time series of surface observation data from Bettles, Alaska on 17 September [click to enlarge]


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Smoke plumes from Saudi Arabian oil facilities

VIIRS Day/Night Band (0.7 µm) and Visible (0.64 µm) imagery from Suomi NPP and NOAA-20 (above) revealed dark smoke plumes from oil refineries and other facilities damaged by drone strikes early in the day on 14 September 2019.EUMETSAT Meteosat-8 Visible (0.8 µm) images (below) showed the south-southwestward transport of the... Read More

VIIRS Day/Night Band (0.7 µm) and Visible (0.64 µm) imagery from Suomi NPP and NOAA-20 [click to enlarge]

VIIRS Day/Night Band (0.7 µm) and Visible (0.64 µm) images from Suomi NPP and NOAA-20 (courtesy of William Straka, CIMSS) [click to enlarge]

VIIRS Day/Night Band (0.7 µm) and Visible (0.64 µm) imagery from Suomi NPP and NOAA-20 (above) revealed dark smoke plumes from oil refineries and other facilities damaged by drone strikes early in the day on 14 September 2019.

EUMETSAT Meteosat-8 Visible (0.8 µm) images (below) showed the south-southwestward transport of the smoke plumes. Thick smoke drifted over Al Ahsa (OEAH), and at one point restricted to 2.8 miles.

EUMETSAT Meteosat-8 Visible (0.8 µm) images, with hourly plots of surface reports [click to play animation | MP4]

EUMETSAT Meteosat-8 Visible (0.8 µm) images, with hourly plots of surface reports [click to play animation | MP4]

Before (13 September) and after (14-15 September) True Color Red-Green-Blue (RGB) images from Terra MODIS and Suomi NPP VIIRS as viewed using RealEarth are shown below.

True Color RGB images from Terra MODIS and Suomi NPP VIIRS, from 13-15 September [click to enlarge]

True Color RGB images from Terra MODIS and Suomi NPP VIIRS, from 13-15 September [click to enlarge]

A sequence of 3 VIIRS Day/Night Band images from Suomi NPP and NOAA-20 (below) showed nighttime views of the smoke plumes, illuminated by the Moon (which was in the Waning Gibbous phase, at 98% of Full).

VIIRS Day/Night Band (0.7 µm) from Suomi NPP and NOAA-20 [click to enlarge]

VIIRS Day/Night Band (0.7 µm) from Suomi NPP and NOAA-20 (courtesy of William Straka, CIMSS) [click to enlarge]

A Meteosat-8 Visible animation spanning portions of 14, 15 and 16 September is shown below.

EUMETSAT Meteosat-8 Visible (0.8 µm) images, with hourly plots of surface reports [click to play animation | MP4]

EUMETSAT Meteosat-8 Visible (0.8 µm) images with hourly plots of surface reports, 14-16 September [click to play animation | MP4]

===== 17 September Update =====

Landsat-8 False Color image [click to enlarge]

Landsat-8 False Color RGB image [click to enlarge]

A 30-meter resolution Landsat-8 False Color RGB image (above) showed a number of smoke plumes from oil facility fires that continued to burn on 17 September.

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Severe thunderstorms in Wyoming, Nebraska and South Dakota

1-minute Mesoscale Domain Sector GOES-16 “Red” Visible (0.64 µm) images (above) showed  the development of thunderstorms that produced large hail, tornadoes and damaging winds (SPC Storm Reports) across eastern Wyoming, northern Nebraska and southern South Dakota on 10 September 2019. Note that many of the storms exhibited Above-Anvil Cirrus Plumes. Pulsing overshooting tops reached -80ºC and colder (violet pixels)... Read More

GOES-16

GOES-16 “Red” Visible (0.64 µm) images, with SPC Storm Reports plotted in red [click to play animation | MP4]

1-minute Mesoscale Domain Sector GOES-16 “Red” Visible (0.64 µm) images (above) showed  the development of thunderstorms that produced large hail, tornadoes and damaging winds (SPC Storm Reports) across eastern Wyoming, northern Nebraska and southern South Dakota on 10 September 2019. Note that many of the storms exhibited Above-Anvil Cirrus Plumes. Pulsing overshooting tops reached -80ºC and colder (violet pixels) just east of Valentine, Nebraska (KVTN) from 0001-0004 UTC (0002 UTC image) — and a few minutes following their collapse, a wind gust of 60 mph was reported in that general vicinity.

The corresponding GOES-16 “Clean” Infrared Window (10.35 µm) images are shown below.

GOES-16 "Clean" Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

The animation shown below is from an experimental product at CIMSS/SSEC, whereby the contours were produced using a ‘deep learning’ artificial intelligence model that was trained on ABI imagery and GLM gridded products to generate the ‘probability of supercell-like features inferred from satellites’, or more concisely, the ‘probability of supercell’. Note that the model does a decent job of identifying active portions of the storms (e.g., persistent Overshooting Tops), which correspond well with severe weather reports.

GOES-16 Visible/Infrared Sandwich RGB and

GOES-16 Visible/Infrared Sandwich RGB and “Clean” Infrared Window (10.35 µm) images, with “probability of supercell” contours and SPC Storm Reports (courtesy of John Cintineo, CIMSS) [click to play MP4 animation]

During the subsequent nighttime hours, GOES-16 Infrared images (below) showed a convective cluster which produced 3 EF-2 tornadoes and damaging winds in and around Sioux Falls, South Dakota (NWS summary). Note that pulsing overshooting tops west of Sioux Falls (KFSD) exhibited infrared brightness temperatures of -80ºC and colder (violet pixels) from 0402-0406 UTC (0404 UTC image), which was about 20 minutes prior to the first tornado reports.

GOES-16 "Clean" Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

GOES-16 “Clean” Infrared Window (10.35 µm) images, with SPC Storm Reports plotted in cyan [click to play animation | MP4]

 

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