A dry, two-dimensional version of the Colorado State University Multi-Dimensional Cloud/Mesoscale Model was used to simulate the cross-valley dynamic and thermodynamic structure in deep mountain valleys during the morning transition period when the nocturnal inversion is destroyed.

Bulk models of the planetary boundary layer (PBL) conventionally rely on diagnostic forms of the turbulence kinetic energy (TKE) equation to determine the entrainment rate. During episodes of rapid deepening or shallowing, the local time rate of change of the vertically integrated TKE becomes significant compared to the difference between gross production and dissipation. A method is presented to determine the entrainment rate in a bulk PBL model...

This paper presents a diagnostic study of two models proposed by Betts (1973a). The first was a model for a well-mixed sub-cloud layer capped by a more stable transition layer. The downward heat flux at the base of this transition layer is here estimated from the thermal structure of the layer to be 15-25% of the surface sensible heat flux. The second model was a model for a two layer lapse-rate structure for the cumulus layer. A sensitivity analysis...

This study examines the location and development of turbulence in the morning hours of boundary layer development over mountainous terrain. Four case study days are presented which illustrate important features on two types of days observed in the mountains of central Colorado.