This paper is a follow-up to a presentation given at the last severe storms conference which discussed return moisture flow in the Eta model and its impact on model forecasts of the pre-convective environment. The parameterization of shallow convection, land-surface physics, and model initialization were all found to play critical roles in the model's ability to produce a realistic boundary layer structure and resultant good forecasts of precipitation, convective available potential energy, and convective inhibition.

This presentation examines recent experiments and changes to the Eta model related to low-level moisture forecasts. Among the important issues are further tests with the shallow convective scheme and the significant upgrade to the land-surface scheme implemented in the model in the summer of 2001. Cases from the spring convective season of 2002 will be presented in detail.