To support the formulation of a simple model that can be used for assessment and prediction of ground vibration levels due to above-ground explosions, a fast field program for layered air ground systems (FFLAGS), developed originally for continuous sound sources, has been extended to enable predictions of propagation from impulsive sound sources in a refracting atmosphere above layered porous and elastic ground. Using a mixture of measured and best-fit parameters, the pulse version of the code (PFFLAGS) has been found to give predictions of the air pressure spectrum above ground and the vertical component of solid particle velocity near the ground surface that compare tolerably well with published data for the spectra and waveforms of acoustic and seismic pulses at short range (60 m) in grass- and snow-covered ground and at longer range (3 km) in forested terrain. The predicted seismic pulses in the presence of the snow cover explain a phenomenon frequently observed for shallow snow covers whereby a high-frequency ground vibration is modulated by a lower-frequency layer resonance [Work supported in part by SERDP SEED Project SI-1410 and Contract Number W90C2K9887EN010001 through the European Research Office of the U.S. Army.]