A coupled normal‐mode approach for the prediction of pulse propagation in a complex coastal environment is presented. In this broadband approach, the received time‐domain sound‐pressure signal is generated by Fourier synthesis using the product of the source signal spectrum and the source‐to‐receiver ocean transfer function. For a given frequency, the basic formulation involves decomposing the acoustic pressure into slowly varying complex envelopes that modulate (mode by mode) analytic, rapidly varying, adiabatic‐mode solutions. A coupled set of differential equations governing these complex modal envelopes is derived and the numerical solution techniques used are discussed. This coupled‐mode approach has been used to model the modal arrival structure in the 1992 Barents Sea Coastal Acoustic Tomography Test. Model results and comparison to the data measured by a vertical hydrophone array are discussed.