Analysis of data from recent experiments ledds to the observation that the distribution of underdense meteor trail durations differs from classical predictions. A new theory for the distribution of underdense meteor trail durations has been developed based upon the assumption of a normal height distribution and lognormal amplitude distribution which leads to a lognormal distribution of the trail durations. It is shown that this model provides a better fit to observed data than the classic model. This model, applied in conjunction with previously reported work, can be used to provide improved predictions of the performance of meteor scatter communications systems.