A new RGB will be implemented into AWIPS in the near future: it is scheduled for the next TOWR-S build to be released in December. Developed by NESDIS Geo Senior Scientist and Cirrus Channel (GOES-R Band 4, 1.38 µm) aficionado Dr. Andy Heidinger, the Day Cloud Type RGB starts with the Day Cloud Phase Distinction RGB (available online here, for example) and substitutes Cirrus Channel (Band 4, 1.38 µm) information for the Band 13 (10.3 µm) Clean Window information in the ‘Red’ component of the RGB. The result is much better detection of thin cirrus in this daytime-only product, as shown in the toggle above that includes the Day Cloud Type and Day Cloud Phase Distinction RGBs as well as the Level 2 Cloud Top Pressure. Note in particular the thin cirrus in the Gulf of Mexico just to the north of the Yucatán Peninsula. Cloud properties for this thin cirrus also show up in the Level Cloud Top Pressure (shown in the toggle above) and in Cloud Top Height.

A similar relationship is shown in the toggle below, from 1806 UTC on 2 November. Note the thin cirrus over central Wisconsin, for example: much more obvious in the Day Cloud Type RGB, and present in the Cloud Top Pressure (and Cloud Top Height) product. A similar relationship is apparent over central North Dakota and over northern Ontario: the Day Cloud Type RGB better isolates regions of highest cirrus compared to the Day Cloud Phase Distinction RGB.

A preliminary Quick Guide for the Day Cloud Type RGB is here. XML Code used to add this RGB to AWIPS is available from the blogpost author.

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

GOES-16 (GOES-East) True Color RGB images created using Geo2Grid (above) showed the east-southeastward drift of ash-laden volcanic clouds from Cumbre Vieja on La Palma in the Canary Islands on 02 November 2021. Since this current eruptive period began on 19 September, intermittent periods of volcanic clouds with an elevated ash content have been observed — and on this particular day, the darker tan to light brown appearance was an indication that higher ash concentrations were likely.

The corresponding GOES-16 Ash RGB images (below) extended an hour further, past sunset. The hues of pink to purple suggested the presence of higher concentrations of volcanic ash.

GOES-16 Ash RGB images [click to play animated GIF | MP4]

Ash Loading product [click to play animated GIF | MP4]

Compared to previous eruptions on 19 September and 09 October, the Ash RGB signature was more pronounced on this day; this was due to a significantly higher ash loading (above) of larger-radius ash particles (below). These 2 radiometrically-retrieved products are from the NOAA/CIMSS Volcanic Cloud Monitoring site.

Ash Effective Radius product [click to play animated GIF | MP4]

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CSPP GeoSphere imagery, above, (click here for a direct link to the animation above in CSPP Geosphere; it will remain there for about 2 weeks before the data are overwritten) shows the evolution of Tropical Storm Wanda on 2 November 2021. (Wanda had transitioned to a Subtropical Storm on 31 October). Convection developed near the storm center and wrapped about halfway around the center. Dry air is also affecting this storm. A 24-hour animation of MIMIC Total Precipitable Water (from this site), below, shows an absence of deep moisture, with the driest air to the west and south.

GOES Imagery also shows dry air near Wanda. Both the low-level water vapor (Band 10, 7.34 µm) and the level 2 Total Precipitable Water product (a clear-sky only product) show dry air signatures: for the water vapor imagery, orange and yellow enhancements; for the total precipitable water, yellow and green enhancements signifying values around 1.3″. The airmass RGB shows Wanda far removes from the tropical airmass that is characterized by a deep green color.

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GOES-16 “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images [click to play animated GIF | MP4]

1-minute Mesoscale Domain Sector GOES-16 (GOES-East) “Red” Visible (0.64 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed areas of deep convection near the center of Subtropical Storm Wanda over the North Atlantic Ocean on 31 October 2021. The circulation of a “Nor’easter” mid-latitude cyclone on 26-27 October (storm summary) remained intact long enough to begin acquiring subtropical characteristics on 31 October (surface analyses: GIF | MP4].       

GOES-16 Air Mass RGB images (below) indicated that while the core of Wanda had become separated from nearby baroclinic surface frontal boundaries, the system was still located beneath a middle- to upper-tropospheric trough of low pressure (500 hPa height) — so it was not yet a true tropical cyclone. Wanda did transition to a Tropical Storm on 02 November.

GOES-16 Air Mass RGB images, with and without surface analysis plots [click to play animated GIF | MP4]

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