Complex forcing, which occurs frequently in the coastal zone, can significantly impact the structure and evolution of mesoscale processes such as fronts and pre-frontal low-level jets. The steep coastal orography of Norway, for example, strongly modulates mesoscale weather events. In the present study, we use the U. S. Navy’s nonhydrostatic mesoscale model (COAMPS) to investigate the landfalling phase of the FASTEX IOP-16 storm of 16-18 February 1997. As the warm front approaches the Norwegian coast, a strong low-level jet develops along the coast with wind speeds in the core of ~48 m/s. The jet extends along the coast and then continues in a coast-parallel orientation well into the North Sea north of the Scandinavian Peninsula. Near-surface wind speeds below the jet core of 30 m/s are in reasonable agreement with surface observations of 20-30 m/s valid at 0300 UTC 18 February.

Trajectory analysis indicates two distinct sources for ageostrophic acceleration into the core of the jet. South of ~62o N, flow is trapped between the approaching front and the steep coastal topography. To the north of a bend in the coast at 62o N, flow passes over the topography and accelerates down the lee side. The strongest wind speeds (~50m/s) are found along this section of the coast. A region of reduced wind speed appears in the lee of the highest orography in central Norway.