A key component of the goals of the Next Generation Air Transportation System (NextGen) is to safely improve the efficiency of the National Airspace System (NAS) by enhancing inefficiency in metroplexes. Based on the use of precise satellitebased navigation, Time Based Flow Management (TBFM), and other advanced techniques and tools, the benefits of a metroplex have been identified through research, indicating that it is capable of making airspace more efficient with less queueing delay and more throughput. However, those studies focused only on operations in normal weather conditions; special weather conditions such as convection were not considered. This study investigated the quantitative impacts of a metroplex under representative operation conditions in convection. Investigations included identification of representative convective weather conditions, analysis of historical radar tracking data in a postmetroplex period, development of queuing system-based models of Terminal Radar Approach Control (TRACON) facility arrival operations with and without metroplex for the North Texas Metroplex, and simulations to evaluate airspace performance in terms of TRACON throughput and arrival delays. Simulation analyses showed an average 27% increase in TRACON throughput at a peak of 15 minutes, as well as 2.39 minutes saved per arrival flight at Dallas/Fort Worth International (DFW) and 1.65 minutes saved per arrival flight at and Dallas Love Field (DAL) when a metroplex is implemented in heavy demand. The increase in TRACON throughput and arrival time saved by a metroplex climbs as traffic grows; however, the increase reaches a limit when the amount of traffic reaches a certain point.