The predictability of anomalous propagation environments

A correspondence is shown between anomalous sightings of ships by a weather radar with an upward tilted beam, and the existence of surface based ducts determined from numerical weather prediction (NWP) models. Since these forecasts are available several days in advance, the existence of such ducts can be predicted in advance. The parameters of these ducts are used in a propagation model to determine regions from which targets can be detected by the radar. Such regions were found to include those where ships were sighted by the radar.