MITRE has made measurements of the wide bandwidth (1-MHz bandwidth) impulse response of HF propagation modes for midlatitude paths in the United States. These paths included near-vertical incidence, 2000 and 3000 km lengths, and primarily supported one-hop F layer propagation. On the basis of these measurements, this paper proposes a stochastic representation for the path loss fluctuation of propagation modes observed for 15-min time intervals. When expressed in decibels, this path loss is modeled as a normally distributed autoregressive process of low order. Estimates of the parameters for this model are extracted from the data for a variety of transmission conditions. A model order of 1 is suggested for link modeling. ¿ American Geophysical Union 1994