The GAP flow subprogram of MAP amassed a huge number of observational platforms to provide a three-dimensional picture of and insight into the evolution of gap flows in a central Alpine valley. Normally, only surface stations rather than instrumented aircraft and remote sensors (scanning Doppler lidar, sodars) will be available.

This paper evaluates how much detail of the gap flow (hydraulic jump-like features, waves, speed extrema) aloft can be inferred from ground-based in-situ measurements only. The complentary information from a fixed mesonet and a mobile car-based platform will be examined in detail. The results will be useful for diagnosing and possibly forecasting flows through other gaps within earth's topography where only observations from a few routine weather stations are available.