GOES-16 (GOES-East) True Color RGB images created using Geo2Grid (above) showed the south-southeastward drift of an ash-laden volcanic cloud from Cumbre Vieja on La Palma in the Canary Islands on 09 October 2021. Since this most recent ongoing eruptive period began on 19 September, intermittent periods of volcanic clouds with an elevated ash content have been observed — and on this day, the darker tan to light brown appearance was an indication that higher ash concentrations were likely.     

In the corresponding GOES-16 Ash RGB  images (below), increasing shades of pink — which suggest a higher ash content — became apparent within a semi-circular volcanic cloud element after 1100 UTC.  

A NOAA-20 VIIRS True Color image as viewed using RealEarth (below) also showed the darker tan to light brown shades of the ash-laden volcanic cloud.

GOES-16 retrieved products from the NOAA/CIMSS Volcanic Cloud Monitoring site (below) indicated that the more distinct pulse of ash-laden volcanic cloud had a maximum height in the 5-6 km range, and was composed of ash particles having an effective radius 10 µm and smaller. 

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The KNP Complex wildfire continued to burn in central California on 04 October 2021, producing a pair of pyrocumulonimbus or pyroCb clouds — one during the atypical late morning hours (beginning around 1530 UTC, or 11:30 am PDT) and the other during the more typical late afternoon hours (beginning around 2130 UTC, or 5:30 PM PDT). 1-minute Mesoscale Domain Sector GOES-17 (GOES-West) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed the pyroCB clouds, fire thermal anomalies or “hot spots” (clusters of red pixels) and cold cloud-top infrared brightness temperatures, respectively. The minimum 10.35 µm temperatures were near -60ºC. Note the relatively warm (darker gray) appearance of the pyroCb clouds in the 3.9 µm images — this is a characteristic signature of pyroCb cloud tops, driven by the smoke-induced shift toward smaller ice particles (which act as more efficient reflectors of incoming solar radiation, contributing to the warmer 3.9 µm brightness temperatures). Note: beginning at 1700 UTC, overlapping GOES-17 Mesoscale Sectors provided imagery at 30-second intervals.

1-minute GOES-17 True Color RGB images created using Geo2Grid (below) showed the first pyroCb cloud as it continued to move northeastward across the California/Nevada border, and then the second pyroCb cloud as it moved northwestward. The change in direction of motion was influenced by the approach of an offshore closed low from the west (250 hPa analysis: 12 UTC | 00 UTC). 

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US Space Force EWS-G1 (formerly GOES-13) Infrared Window (10.7 µm) images (above) showed
Hurricane Shaheen weakening to a Tropical Storm shortly after it made a rare landfall along the coast of Oman on 03 October 2021. The storm exhibited an eye at times as it was a Category 1 Hurricane over the Gulf of Oman. This was likely the first tropical cyclone to make landfall along that coastal portion of Oman since 1890 (Wikipedia).

Meteosat-8 Infrared images, with contours of deep-layer wind shear from the CIMSS Tropical Cyclones site (below) indicated that the storm was moving through an environment of low shear.

Suomi-NPP VIIRS True Color RGB and infrared Window (11.45 µm) images viewed using RealEarth (below) showed the Category 1 Hurricane at 0927 UTC.

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GOES-17 (GOES-West) Dust RGB and Ash RGB images (above) revealed a plume of resuspended volcanic ash — from the 1912 eruption of Novarupta-Katmai — moving southeastward across the Shelikof Strait toward Kodiak Island in southern Alaska on 02 October 2021. The remnant ash on the surface was lofted by strong northwesterly winds along  the rear edge of Hurricane Force and Storm Force lows in the Gulf of Alaska (surface analyses), and imagery suggested that the ash  plume (shades of pink to magenta) began to develop just after 0600 UTC. At Buoy 46077 in the Shelikof Strait, a peak wind gust of 35 knots occurred around 14 UTC.

Both RGB image combinations use the same ABI spectral bands, but in this case the plume of airborne ash showed up a bit better on the Dust RGB  (below) because of how the 3 components of that RGB are scaled.

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