A daytime VIIRS RGB pseudo composite for snow detection

- A daytime Snow RGB product for VIIRS is proposed.
- Temporal evolution of snow is highlighted.
- Snow surfaces can be distinguished through thin clouds.

RGB pseudo composite imagery is a robust and fast processing technique for satellite observations to provide near real-time synthesized weather information to forecasters. The technique consists of superposing three images resulting from a linear combination of multi-spectral observations and corresponding them to red, green and blue. A new algorithm for the detection of snow during daytime has recently been developed for the Suomi-NPP VIIRS instruments. The algorithm uses five VIIRS bands including that centered at 2.25 μm to enhance snow detection and that centered at 1.24 μm to highlight the temporal variability of the snow cover. Furthermore, this paper shows the capability of the algorithm to detect snow under thin cloud conditions. This product is already provided in near real-time to forecasters of the French national weather service, Météo-France.