Blowing dust from the Copper River Delta in south-central Alaska

October 20th, 2020 |

GOES-17

GOES-17 “Red” Visible (0.64 µm) and Dust RGB images [click to play animation | MP4]

Strong gap winds accelerating out of the Copper River Valley along the southern coast of Alaska were lofting fine particles of glacial silt/sand and transporting those aerosols southward across the Gulf of Alaska on 20 October 2020. 1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm) and Dust Red-Green-Blue (RGB) images (above) displayed the plume of airborne dust during the period of 1700-2300 UTC.

A good visualization of the dust plume was provided by GOES-17 True Color RGB images created using Geo2Grid (below).

GOES-17 True Color RGB images [click to play animation | MP4]

GOES-17 True Color RGB images [click to play animation | MP4]

A comparison of Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images at 2040 UTC is shown below — note that the dust plume appeared warmer (darker shades of gray) on the Shortwave Infrared image, since the small dust particles were efficient reflectors of incoming solar radiation.

Suomi NPP VIIRS Visible, Shortwave Infrared and Infrared Window images [click to enlarge]

Suomi NPP VIIRS Visible (0.64 µm), Shortwave Infrared (3.74 µm) and Infrared Window (11.45 µm) images [click to enlarge]

The dust plume also exhibited a good signature in the VIIRS Aerosol Optical Thickness (AOT) product from the eIDEA-AK site (below).

VIIRS True Color RGB and Aerosol Optical Thickness images [click to enlarge]

VIIRS True Color RGB and Aerosol Optical Thickness images [click to enlarge]

Thundersnow in South Dakota and Minnesota

October 20th, 2020 |

GOES-16 Day Cloud Phase Distinction RGB images, with an overlay of GLM Flash Extent Density [click to play animation | MP4]

GOES-16 Day Cloud Phase Distinction RGB images, with an overlay of GLM Flash Extent Density [click to play animation | MP4]

GOES-16 (GOES-East) Day Cloud Phase Distinction Red-Green-Blue (RGB) images with a overlay of GLM Flash Extent Density (above) displayed clusters of convection — some with brief bursts of lightning activity — which were moving eastward and enhancing snowfall rates from Watertown, South Dakota (station identifier KATY) into far western Minnesota on 20 October 2020. The resulting snowfall amounts included 6.0 inches near Watertown and 8.0 inches near Ortonville, Minnesota.