GOES-17 Shortwave Infrared imagery, above, shows the hot-spot associated with the latest eruptive phase of the Halema’uma’u Crater on Kilauea’s southern slope. (Click here for webcams).

The Day Night band from VIIRS on board Suomi NPP and NOAA-20 show the light source from the eruption as well, as shown in the toggle below (imagery from the Honolulu Direct Broadcast site, here)

The NOAA/CIMSS Volcanic Cloud Monitoring Web Portal (i.e., VOLCAT — link) include a Kilauea sector under the Washington DC VAAC tab; an imagery example is here.

FDCA — the Fire Detection and Characterization Algorithm — should have a signal here but does not. The landcover dataset used for the product is missing Hawaii. Fires aren’t looked for when land does not exist, even if its absence is in error. NOAA/NESDIS Scientists and their partners at CIMSS are working to correct this oversight.

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As of 1400 UTC on 30 September, GOES-17 Level 2 products are flowing into National Weather Service forecast offices via the Satellite Broadcast Network (SBN). An example of the improvement of GOES-17 v. GOES-16 is shown in the toggle above that samples the KNP Complex fire in Tulare County California (click here for a toggle that is not so zoomed in!). The GOES-17 shortwave IR shows warm pixels associated with the fire; GOES-17 Fire Power aligns with the GOES-17 pixels, and show much larger values (approximately 3x greater) than the GOES-16 products from the same time.

A further utility of Level 2 products is shown below, from 29 September. The Day Cloud Phase Distinction RGB includes ABI Band 5, the 1.61 ‘snow-ice’ band that indicates glaciation by a change in reflectance at that band. Thus, the color of the RGB can change where ice crystals are present. There is a Level 2 product, however, that computes what the phase most likely is, and that is shown in a toggle at 1951 UTC below. Visual inspection of an RGB may not be enough to ascertain cloud type, particularly on this day for the clouds off the coast of Oregon. A good practice is to load the Level 2 product underneath the image so that sampling can give a quantitative estimate, as shown at bottom.

Available GOES-17 Level 2 Products include: Aerosol Detection and Aerosol Optical Depth, Rain Rate/Quantitative Precipitation Estimates (original algorithm), Clear Sky Mask, Fire Detection and Characterization (that is, Fire Hotspots), Land (and Sea) Surface Temperature, Derived Stability Indices, Total Precipitable Water, Derived Motion Wind Vectors, Cloud Particle Size Distribution, Cloud Top Pressure, Cloud Top Phase, Cloud Top Temperature and Cloud Optical Depth. The animation below (imagery courtesy Lee Byerle from TOWR-S) steps through the various Level 2 products at/around 1800 UTC on 30 September. Another version that loops through many GOES-17 Level 2 products. A visible band is included for reference.

Special Note: Users of GOES-17 Level 2 Products must remember that, depending on the time and day, Level 2 Products may be affected by degraded ABI band quality, an issue related to the GOES-17 Loop Heat Pipe that is not performing up to spec. For more information on the Loop Heat Pipe and it effect on GOES-17 imagery, visit this site and this site.

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Scientists at STC and at SPoRT have created a website to view NUCAPS profiles using Sharppy and cloud resources. The animation above shows the user interface for Observed Soundings (i.e., upper-air soundings), for NUCAPS Soundings for different passes, and NAM Nest model profiles. The green points have been chosen for subsequent display. Points near KARB — Aberdeen, South Dakota — were selected; on this day, subsequent NOAA-20 NUCAPS passes produced data 90 minutes apart very near Aberdeen.

The toggle between the 0000 and 1200 UTC radiosondes at Aberdeen shows a general moistening of the atmosphere (especially above 500 mb). NUCAPS soundings in between give a forecaster information on the character of that increase: linear? step-wise? The two NUCAPS soundings, below, separated by 90 minutes, and in between the two radiosondes, show moistening after 0700 UTC.

NUCAPS soundings are volumetric, in comparison the radiosonde and model-derived soundings, both of which are valid at one point that is ascending through the atmosphere. NUCAPS soundings from NOAA-20 are a blend of information from up to 9 CrIS (Cross-track Infrared Sounder) fields of regard and one Advanced Technology Microwave Sounder (ATMS) footprint. A comparison between radiosonde or model soundings and NUCAPS soundings should always be tempered with that information.

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GOES-16 Visible (0.64 µm, top), Shortwave Infrared (3.9 µm, center) and Infrared Window (10.35 µm, bottom) images [click to play animation | MP4]

Fires burning in far northern Paraguay on 29 September 2021 created a pyrocumulonimbus or pyroCb cloud — GOES-16 (GOES-East) “Red” Visible (0.64 µm), Shortwave Infrared (3.9 µm) and “Clean” Infrared Window (10.35 µm) images (above) showed the pyroCB cloud, fire thermal anomalies or “hot spots” (clusters of red pixels) and cold cloud-top infrared brightness temperatures, respectively. The minimum 10.35 µm temperature was -47.6ºC at 1840 UTC. Note the relatively warm (darker gray) appearance of the pyroCb cloud 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).

A Suomi-NPP VIIRS Infrared Window (11.45 µm) image at 1751 UTC as viewed using RealEarth (below) revealed cloud-top infrared brightness temperatures in the -60s C (shades of red). Surface temperatures at nearby sites had reached 38ºC (100ºF) by 18 UTC. 

Suomi-NPP VIIRS Infrared Window (11.45 µm) image at 1751 UTC [click to enlarge]

South American pyrocumulonimbus clouds are fairly uncommon — since the first documented case in 2018, only 7 other pyroCbs have been identified over that continent. 

Thanks to Mike Fromm, NRL, for alerting us to this latest pyroCb case. Additional information is available from Metsul.com.

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