In this presentation, the current work to improve the RU-RTMA will be described, including testing and evaluation of variations in the background error covariance and assumed observation errors for surface observations. The testing is being conducting using real-time experimental versions of the RTMA/RUA based on the real-time experimental HRRR, and will include CONUS and Alaska versions. Another key aspect of the work focuses on the impact of the observation data window and cutoff period on the 15-min analysis, given that the background HRRR model is only updated hourly.
Work toward the 3D RU-RTMA will also be described. 2D fields that are intrinsically a function of 3D space (PBL height, precipitable water, ceiling, etc.) are diagnosed from the 3-D RU-RTMA fields, giving full physical consistency through having a very accurate high-resolution model background. Extending the operational RTMA to three dimensions allows for the creation of highly useful nowcasting products, including full-column representation of standard meteorological fields such as temperature, water vapor, and wind, as well as hydrometeors (i.e., clouds, precipitation of all forms), and eventually aerosols. The 3D RU-RTMA also includes land-surface diagnostics (e.g., soil moisture, snow state from multi-level land-surface fields), and convective (e.g., hail size, supercell rotation tracks) fields, developed through collaboration with the National Water Center (NWC) and National Severe Storms Laboratory (NSSL), respectively. The 3D RU-RTMA will potentially improve analysis fields for the NOAA National Blend of Models (NBM) project and add a 3-dimensional perspective including cloud-hydrometeor fields. It could also allow merging in of the NCEP/SPC Hourly Mesoscale Analysis and also provide an initial set of fields for a unified NOAA nowcast system.