Extensive observational data sets of landfalling storms along the west coast of the United States have been collected during the California Landfalling Jets (CALJET) and Pacific Landfalling Jets (PACJET) experiments. Simulations of some of these storms using the Penn State/NCAR Mesoscale Model (MM5) have been compared to these observations and used to address various modeling and physical process issues. The highlights of these analyses will be discussed in this presentation. The scientific issues examined include some of the following: a) the effects of nearshore surface sensible and latent heat fluxes on coastal precipitation, b) the effects of surface momentum, sensible heat and latent heat fluxes during interstorm periods on the preconditioning of the interstorm environment ahead of subsequent landfalling storms, c) the validation of coastally-generated atmospheric structures and processes, including blocking effects, d) the impact of satellite/aircraft observations for initializing simulations of landfalling storms, and e) the in-situ, aircraft, and model validation of satellite observations of the mesoscale storm structure. Observations and simulations from the storms of Feb. 2-3, 1998, Feb 6-7, 1998, and Feb. 19, 2001 are used to illustrate the key results.