The impact of positive-definite moisture transport on NWP precipitation forecasts
Skamarock, W. C., & Weisman, M. L. (2009). The impact of positive-definite moisture transport on NWP precipitation forecasts. Monthly Weather Review, 137, 488-494. doi:10.1175/2008MWR2583.1
A positive-definite transport scheme for moisture is tested in a nonhydrostatic forecast model using convection-permitting resolutions. Use of the positive-definite scheme is found to significantly reduce the large positive bias in surface precipitation forecasts found in the non-positive-definit... Show moreA positive-definite transport scheme for moisture is tested in a nonhydrostatic forecast model using convection-permitting resolutions. Use of the positive-definite scheme is found to significantly reduce the large positive bias in surface precipitation forecasts found in the non-positive-definite model forecasts, in particular at high precipitation thresholds. The positive-definite scheme eliminates spurious sources of water arising from the clipping of negative moisture values in the non-positive-definite model formulation, leading to the bias reduction. Show less
