The surface wave spectra from the Atlantic Ocean Remote Sensing Land-Ocean Experiment (ARSLOE), during the passage of a 26-hour storm, were subjected to an empirical eigenfunction analysis. Results from the analysis are interpreted as the spatial and temporal variation of surface gravity waves propagating from deeper water into the shallow region where breaking finally occurs. The temporal variation is found to be approximately 7-17% of the total variance in the data and is considered as stochastic, with a fluctuation of about 2-3 cycles that appear correlated with the variation of the atmospheric forcing. The spatial variatiion (1-3%) is significantly less than the temporal variation but exhibits a deterministic part, indicating that the wave processes associated with the spatial variation can be considered deterministic. The principal eigenfunctions obtained from the analysis provide a good representation of the principal variations in the wave spectra as shown by the first eigenvalue of the covariance matrices. The radiative transfer equation is projected onto the eigenvector space, and the source function obtained from the suitable projection function is presented. By using the information extracted from the empirical eigenfunction analysis, various source functions for the wave field are inferred The source functions evaluated in the present study are associated with the wave mechanisms of refraction and shoaling, atmospheric input, bottom friction, and wave-wave nonlinear interaction. The functions provide a good picture of the spectral wave energy balance, although further development of the current work can provide more detailed information about the energy transfer and may enhance the present picture of wave energy balance in the shallow water.