Using the NAMRR Cloud Analysis in a Cycled Radar Data Assimilation Forecast of the 26 December 2015 Texas Tornado Event

Advancements in the state of storm scale data assimilation in the experimental rapid refresh configuration of the NAM (hereafter the NAMRR) are ongoing. A current goal is to use a hybrid EnKF/GSI-based-3DVAR technique to assimilate radar reflectivity and velocity among other fields to update multi-scale initial conditions for the convection-allowing forecast model. However, the current state of radar data assimilation in the NAMRR uses only a deterministic cloud analysis which inserts condensate species and adjusts the temperature and humidity fields corresponding to existing observed clouds and storms in the initial conditions of the forecast model, constituting one portion of the full assimilation technique that will eventually be used. Tests of the current physical changes made by the cloud analysis for an example case involving a mixed morphology/mixed phase precipitation event that occurred in the southern U.S. on 26 December 2015, in which an EF4 tornado occurred in the Dallas-Ft. Worth metro area, are currently underway. Results will be presented detailing the physical changes made by the cloud analysis and the impacts of the hourly-cycled radar data assimilation on subsequent forecasts of the event.