Individual locusts fly at modest airspeeds, roughly comparable to a brisk walk, so wind speed dominates the resulting track. Swarms move downwind across long distances, occasionally crossing seas, and daytime flight is largely continuous while conditions are warm.
The consequence is not random. Wind convergence zones, such as the Intertropical Convergence Zone, are where opposing air masses meet, and they are also where rainfall concentrates. A swarm passively carried downwind is therefore delivered towards ground that has recently had rain and so carries fresh vegetation and damp soil suitable for egg laying. No navigation is required for the outcome to look navigated.
This is why locust forecasting is meteorological work. Agencies model wind fields and rainfall rather than tracking insect intentions. The limitation is that fine-scale swarm behaviour, including the choice of settling sites and the timing of take-off, is only partly captured by wind models, so predicted and actual arrival can diverge.