The Near Real Time (NRT) NOAA-21 - formerly the Joint Polar Satellite System-2 (JPSS-2) Visible Infrared Imaging Radiometer Suite (VIIRS) hourly top-of-atmosphere, at-sensor nighttime radiance product called VIIRS/JPSS2 Granular Gridded Day Night Band 15 arc-second Linear Lat Lon Grid Night. Known by its short-name, VJ246A1G_NRT, is same as VJ246A2_NRT except that this product is generated hourly, cumulative from start of day through the hour the file is generated for. This product contains 26 Science Data Sets (SDS) that include sensor radiance, zenith and azimuth angles (at-sensor, solar, and lunar), cloud-mask flags, time, shortwave IR radiance, brightness temperatures, VIIRS quality flags, moon phase angle, and moon illumination fraction. It also provides Quality Flag (QF) information specific to the cloud-mask, VIIRS moderate-resolution bands M10, M11, M12, M13, M15, M16, and DNB.