19. KEY WORDS (Continue ott reverse side if necessary and identify by block number)

A two dimensional boundary layer model is developed for the study of diurnal cycles in boundary layer convergence over synoptic scale sloping terrain and thermally inhomogeneous surfaces. To properly resolve the terrain configuration,a local terrain following coordinate system is developed. The local coordinate system has characteristics which are superior to the terrain following coordinate systems commonly used. Truncation errors are significantly reduced in the local system so variations In the flow field due to physical forcing are easily discernable from those due to truncation error. Also, it appears that the local system can resolve coarser terrain configurations under numerically stable conditions. The model exhibits a sensitivity to latitude. The phase of the maximum vertical velocities forecast by the model occurs six hour