The Nighttime Microphysics RGB Imagery, provided by S-NPP VIIRS in above image, efficiently highlights the low cloud and fog areas in aqua to dull gray, to allow forecasters to better see where hazards exist to transportation (aviation, public, or marine). This VIIRS image also provides forecasters with a look at the new geostationary capabilities that will be available soon with GOES-16 ABI. This Nighttime Microphysics RGB Imagery was originally created by EUMETSAT around 2006, transitioned by NASA/SPoRT to forecasters within the NOAA Satellite Proving Ground over the last 5 years, and recently adopted by GOES-16 as one of the many RGB products that will be available to better utilize the ABI three fold increase in the number of bands over the current GOES imager. Currently, the Nighttime Microphysics RGB Imagery from VIIRS as well as several AVHRR and MODIS instruments is regularly used by forecasters in operations, which has allowed them to gain experience in preparation for this new capability from GOES-16.
On February 8, 2017 Dense Fog Advisories were in place across the Gulf Coast and parts of the Southeast (see image below) and there have been many similar events in the region for this winter.
Near 1000 UTC (~4:00am CST) large areas of low ceilings and visibility were occurring in the advisory regions, as seen in the first image of the post. In the images below, take a look at how the Nighttime Microphysics RGB Imagery (this time from NOAA-19/AVHRR) compares to using a single longwave infrared channel in the split scene of the Gulf Coast region and then compare this with the same scene where only the Nighttime Microphysics RGB Imagery is shown. Note that the fog and clear areas can look similar in the infrared image and that the fog itself is a bit warmer than the ground areas in Texas. For help interpreting these types of images, NASA/SPoRT has RGB Quick Guides available at https://weather.msfc.nasa.gov/sport/training/ .