One of the most popular GOES products is the True Color RGB. There’s a lot to like about it: a constantly updating full color view of the planet, watching clouds swirl above sapphire seas and emerald forests. It can be positively mesmerizing to watch loops of this product, at least until the sun sets, the terminator arrives, and the visible reflectances go away.

There is an important cacceat to remember, though. The GOES true color product isn’t really a true color image of the planet. The GOES ABI instrument is not like a consumer digital camera, in which separate channels record the red, blue, and green reflectance and assemble those into an easily recognizable photograph. Instead, while ABI has a blue channel (Channel 1, 0.47 microns) and a red channel (Channel 2, 0.64 microns), it doesn’t have a green channel. Instead, ground processing does a little trickery. Channel 3, at 0.86 microns, is very sensitive to vegetation. What we can do instead is create an RGB product where red is red, blue is (wait for it…) blue, and green is a channel that is strongly representative of surfaces that are green. Most of the time this works just fine for the majority of users.

However, this all relies on the assumption that vegetation is green. But what happens if you have a lot of vegetation that isn’t green at all? How would that appear on the GOES True Color RGB? This image, taken on 17 November 2025, shows the southeastern United States as seen from GOES-19. Note how lush the forests in this region look. There’s lots of green throughout the region. If you were looking to identify where fall colors weer at their peak, it might be challenging to do so with this image.

VIIRS tells a different story. This image, obtained via direct broadcast, was taken at approximately the same time from the NOAA-21 satellite. The VIIRS instrument has true red, green, and blue channels, so a true color RGB is much closer to what our eyes would perceive if we were looking down from space. Note how the green areas of this image are much smaller in extent. Florida, southern Alabama, and the coastal regions of Georgia and South Carolina still retain much of their verdant colors as before. However, the hardwood forests of Appalachia, including the dense forests along the Tennessee / North Carolina border, are much browner than before.

The following slider allows you to directly compare the two images to see how they differ. Check out how the colors along the coasts, where trees are still green, are mostly the same between the two images, but they are very different in the forested regions where leaves have already turned.

This slider also does a good job of illustrating parallax and how cloud height exacerbates it. As you slide the bar back and forth, note that there’s very small displacements in the positions of the low clouds, like the popcorn convection throughout the Florida peninsula. However, the high cirrus (likely aged contrails) over Georgia and Alabama show a much greater horizontal displacement due to the very different scanning positions of the two instruments.

This simple example shows that it’s important to remember that the GOES ABI True Color product is really representing an idealized version of what we think the planet is supposed to look like, rather than a direct capture of what it actually looks like right now. Note that this is not as much of an issue with many other geostationary satellites. The Flexible Combined Imager (FCI) on EUMETSAT’s Meteosat-12, the Advanced Himawari Imager (AHI) on the Himawari series operated by Japan, and the Advanced Meteorological Imager (AMI) on South Korea’s GEOKOMPSAT-2a all have the necessary channels to produce full spectrum true color images. Note that this is not true for SEVIRI, still in operational use over the Indian Ocean on Meteosat-9 and in wide use in central and eastern Asia. EUMETSAT’s Natural Color RGB is a combination of 1.6 (red), 0.8 (green), and 0.6 (blue), which has even fewer visible channels than the GOES True Color.

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The Blue Origin New Glenn NG-2 mission launched from Cape Canaveral Space Force Station, Florida at 2055 UTC on 13 November 2025. A multi-panel display showing all 16 ABI spectral bands on the GOES-19 (GOES-East) satellite (above) revealed distinct thermal signatures in the 3 Water Vapor bands (08/09/10) at 2056 UTC, with a more subtle signature in the CO₂ band (16) and one faintly-brighter pixel in the Cirrus band (04). A signature of the rocket booster condensation cloud was evident in all 16 ABI spectral bands, closer to the coast. Unfortunately, there was no 1-minute GOES-19 Mesoscale Domain Sector coverage over that area — so only 5-minute CONUS Sector imagery was available.

A slightly longer sequence of GOES-19 True Color RGB images (below) highlighted the rapid dissipation of the rocket booster condensation cloud as it drifted eastward away from the launch site. Farther inland, the dense smoke plume from a prescribed burn is apparent.

A plot of rawinsonde data from Cocoa Beach, Florida (KXMR) during the morning preceding the launch (below) showed dry air aloft throughout much of the troposphere — which contributed to the fairly rapid dissipation of the rocket booster’s condensation cloud as it drifted away from the coast.

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As mentioned in Wednesday’s blog post, a significant geomagnetic storm continued to make impacts last night, with many across the central and northern portions of North America able to relatively easily spot the aurora borealis for the second night in a row. As anyone who has watched the aurora from the ground knows, it is a dynamic phenomenon with notable shifts in pattern and intensity over the course of minutes-to-hours. One unique way that we can examine the evolution of the aurora over the course of a night is to view a time series of VIIRS Day Night Band imagery from the JPSS constellation. While VIIRS imagery is often composited to provide wider geographic coverage, that technique has the downside of losing the short-term temporal aspect of the features in the image. Below is an 8 image sequence of VIIRS DNB imagery over the eastern and central United States covering from 6:06 – 9:47 UTC on November 13th, 2025. This features data from S-NPP (just back from an instrument anomaly), NOAA-20, and NOAA-21. This data was captured by SSEC’s direct broadcast antenna in Madison and processed with low-latency locally using CSPP SDR and Polar2Grid.

The large, bright white streaks over southern Canada indicate where the aurora was overhead at the time the satellite passed over. During times when the aurora was more dim, it takes on a more uniform east-west origination around 50 degrees North latitude, but when it is more bright and intense, the pattern of the aurora becomes more agitated and full of swirls. These short-lived periods of more intense aurora activity may be attributable to a phenomenon called geomagnetic substorms. The ESA has a nice explainer on the mechanisms behind substorm auroras here.

Alaska is well-known for its frequent aurora viewing opportunities, and last night’s storm was no exception. Thanks to direct broadcast VIIRS data collected by the Geographic Information Network of Alaska and processed at the University of Alaska Fairbanks, we can pick up from roughly the same time as the end of the loop above, providing coverage from 9:42 – 16:02 UTC. The intensity of the aurora over Alaska was generally fading through about 13:53 UTC, before becoming dramatically brighter during the 14:23 and 14:43 UTC overpasses over the northern half of the state.

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The Bald Mountain brush fire had been burning for several days in far western Virginia — but flared up on 12 November 2025, due to ongoing moderate drought conditions and an increase in winds west of a surface trough of low pressure. 1-minute Mesoscale Domain Sector GOES-19 (GOES-East) Visible images with an overlay of the Fire Detection and Characterization Algorithm Fire Mask derived product (above) showed an initial fire detection at 1251 UTC in far northeast Craig County — and a smoke plume later became apparent as wind gusts at nearby METAR sites such as Roanoke (KROA) reached 30-37 kts during the afternoon hours.

However, 1-minute GOES-19 GeoColor RGB images (below) depicted the smoke plume with greater clarity during the daytime hours — and Next Generation Fire System (NGFS) Fire Detection polygons portrayed a thermal signature of the Bald Mountain fire several hours earlier than the Fire Mask derived product.

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