A study of the relation between the large-scale flow and the topography is carried out with the aim of understanding its role in the precipitation forecast during the Intensive Observation Periods (IOPs) of the Mesoscale Alpine Programme(MAP). Mesoscale model simulations for all wet MAP cases (i.e., cases involving precipitation) are performed to study the modification of the large-scale flow by the Alps and the role of the consequent mesoscale flow in the predicted precipitation pattern. The high density observations collected during the MAP IOP allows for detailed verification of the model forecast. Sensitivity tests varying the topography (alpine barrier) are performed to evaluate its role in determining the model forecast of the location and amount of rainfall for all cases.