Several studies have suggested that Tropical easterly waves are related to the development of gulf surges over the Gulf of California. This hypothesis is tested using the Pennsylvania State University – National Center for Atmospheric Research Mesoscale Model version 5 (MM5v3) using a grid spacing of 20 km. Two 30-day integrations of the model beginning 1 July 1990 are conducted, where the model domain is centered over Mexico. One integration uses boundary conditions from the operational AVN model analyses at 12 h intervals. The second integration uses boundary conditions in which waves with periods between 3 and 7 days have been removed from the analyses using a simple spectral filter below 30 degrees north. Results from these two simulations are compared to highlight the role(s) played by the Tropical easterly waves in the development of both gulf surges and deep convection over the southwestern United States. Implications for operational forecasting of these events will be discussed.