This report presents the methodology and results of an analysis of the accuracy of meteorological computer messages derived from 1 a Profiler Virtual Module PVM using its data assimilation DA capability as compared with 2 a PVM with its DA capability turned off. The PVMs Nowcasting accuracy was compared to the currently fielded artillery meteorological MET system, the Computer Meteorological Data-Profiler is described in an earlier technical report in 2014 by J Cogan, P Haines, J Seik, and A Wetmore, ARL-TR-7149 however, those comparisons were based on testing in which both systems relied only on Global Forecast System data for initialization and did not include assimilation of World Meteorological Organization data. In this report, accuracy is defined in terms of the closeness of the PVMs Nowcast fields to coincident upper air rawinsondes soundings obtained from Yuma Proving Ground YPG, Arizona. The YPG soundings made at the YPG MET station were launched and assimilated by one of the PVMs between 1200 and 0000 Coordinated Universal Time UTC. The assimilated soundings were made every 3 h and noningested soundings were used for ground truth. The noningested YPG MET soundings were launched at intermediate times, and noningested soundings were made at 2 other YPG locations that were launched at varying times between 1200 and 0000 UTC.