Abstract: Contrails are aircraft-induced ice clouds that are estimated to account for 57% of aviation’s anthropogenic climate impact. However, an individual contrail's impacts are highly uncertain, and accurate models of individual contrails are needed in order to accurately predict and optimize the effects of different mitigation efforts. Existing high-fidelity (e.g. LES) contrail models are computationally expensive and therefore infeasible to use for large-scale simulation, while faster zero-dimensional models must necessarily rely on parameterizations of contrail properties which may not apply in all circumstances. The APCEMM model attempts to bridge this gap as an intermediate-fidelity model that features binned microphysics and 2-D advection/diffusion, while still being fast enough to run at scale. Here we evaluate the accuracy of APCEMM in predicting the shape, optical properties, and size of contrails observed in satellite LIDAR observations which have been attributed to specific flights. We classify differences into those due to our estimate of the ambient meteorology and those due to the APCEMM model’s assumptions about the physics. Using this data, we establish the degree to which accurate modeling of the contrail cross-section is necessary - or unnecessary - to understand and predict individual contrail climate impacts under different mitigation scenarios.