This paper presents an approach to predict the interference effects of a transient electromagnetic environment (EME) caused by an aggregate of wideband transmitters on a traditional narrowband victim. Due to the constraint of the narrowband receiver, it is sufficient to evaluate such wideband parameters of transmitter as effective isotropically radiated average power (EIRP) and antenna gains, etc. at the center frequency of the victim. Consequently, the single frequency propagation models used in traditional radio link calculations has been utilized in conjunction with the models described in this paper to estimate the basic transmission loss over the propagation path from the wideband transmitter to the narrowband receiver, and consequently to calculate the interference power at the victim.