GOES-16 (GOES-East) True Color RGB images created using Geo2Grid (above) showed the southward expansion of a volcanic cloud following an eruption of Cumbre Vieja in the Canary Islands at 1410 UTC (advisories) on 19 September 2021. The eruption caused some evacuations on the island of La Palma. The ash loading was relatively light, as no distinct ash signature (shades of pink to magenta) was seen the corresponding GOES-16 Ash RGB  images (animated GIF | MP4) — however, pale shades of green in those RGB images did suggest the presence of SO2 within the volcanic cloud (below). Lower-altitude winds transported some of the volcanic cloud material southwestward, while higher-altitude winds carried SO2-rich parts of the volcanic cloud toward the southeast (Tenerife, Canary Islands sounding).

A distinct thermal anomaly (cluster of hot pixels, yellow to red enhancement) was seen at the eruption site on GOES-16 Shortwave Infrared (3.9 µm) images (below) — this thermal signature briefly subsided about 2 hours after the eruption, but then resumed for several additional hours. The bulk of any significant volcanic ash remained aloft, with no restrictions to surface visibility reported at La Palma or Tenerife.

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The VIIRS Imagery Viewer hosts 7 days’ worth of imagery over North America — refreshed daily — for all 22 VIIRS channels. Five of these channels are imaging-resolution bands (I-Bands) with a resolution of 375 m, and sixteen are moderate-resolution bands (M-Bands) with a resolution of 750 m. The viewer also hosts Day Night Band (DNB) images that provide unique nighttime perspectives. CIMSS acquires the data from the Suomi-NPP and NOAA-20 polar-orbiting satellites via Direct Broadcast antennas.  As new images become available from the Visible Infrared Imaging Radiometer Suite (VIIRS), they are processed via CSPP software and presented in a thumbnail directory, usually within 60 minutes of acquisition onboard the spacecraft. The thumbnails link to high resolution full overpass images. In addition to the individual bands, the VIIRS Imagery Viewer features multiple Level-2 products. The most popular are True and False Color images.  

CIMSS Direct Broadcast is one of the few places to access images in all 22 bands collected by VIIRS. Previously (and still) available via ftp (at https://ftp.ssec.wisc.edu/pub/eosdb/), the VIIRS Imagery Viewer makes it easier for students and citizen scientists to access the data, especially students participating in the JPSS Virtual Science Fair.  

Visit the VIIRS Imagery Viewer at https://cimss.ssec.wisc.edu/viirs/imagery-viewer/. 

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Clear skies to the west of Oregon and California in the past two days have allowed VIIRS data (VIIRS — the Visible-Infrared Imaging Radiometer Suite flying on both Suomi-NPP and NOAA-20) to produce compelling imagery of the Sea Surface using Advanced Clear Sky Processing for Ocean (ACSPO) algorithms. VIIRS imagery is downlinked at the Direct Broadcast site at the UW-Madison; data are processed using CSPP. Purple values are just a bit cooler than 50º F; Yellow values are in the mid-60s ºF.

ACSPO estimates of SSTs are important over the Pacific Northwest because the Level 2 SST GOES-16 product is not computed near the GOES-16 limb. Level 2 Clear Sky mask is not computed out to the limb, as shown below, and GOES-16 SSTs (Full-Disk only products) are not computed out to the edge of the Clear Sky mask! So, if you want satellite-derived SSTs (GOES-17 Level 2 products are not yet widely available), Polar-Orbiting data are the way to go.

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AWIPS-ready ACSPO SST files are available from via an LDM feed from CIMSS.

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Hurricane Nicholas made landfall on the Gulf Coast shortly after 0530 UTC on 14 September. It is a challenge to determine the storm center from the animation above, although deep convection is suggestive of its location. Note the collapse of deep convection as well at the end of the animation. Radar imagery, below (from this site), is helpful in placing the storm center.

MetOp-B overflew Nicholas at 0315 UTC shortly before landfall. ASCAT winds (from this site) at 0315 UTC show the circulation center very close to the shoreline. A similar image from the OSI SAF Multiplatform viewer is here.

Nicholas is embedded in very moist air. A 24-hour MIMIC Total Precipitable Water animation, below, shows the moisture plume. Heavy rain is forecast for the central Gulf Coast.

Nicholas has weakened to a Tropical Storm as of 0900 UTC on 14 September. Refer to the National Hurricane Center website for more information.

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