Evaluation of a multi-level primitive equations limited area model for short range prediction over Indian region

Abstract

A five-level primitive equations limited area model (LAM) in flux form is considered in this study for short range prediction in the tropics. The model physics includes boundary layer, dry convective adjustment, deep cumulus convection and large scale condensation. The effect of mountains including Himalayas is incorporated through sigma coordinate formulation. An efficient split-explicit time integration scheme with time dependent lateral boundary conditions are used. This study addresses the problem of short range numerical weather prediction over Indian sub-continent during SW monsoon season. The model is integrated up to 48 hours with four typical cases representing a cut-off low, onset vortex, mid-tropospheric cyclone and monsoon depression situation during special observing period-II (MONEX) of the FGGE-1979. The model produced reasonably good forecasts of surface pressure, wind and temperature fields up to 48 hours. However, the precipitation forecasts were not very satisfactory