Jp2.6 Nids-Based Intermittent Diabatic Assimilation

INTRODUCTION The lack of accurate moisture/cloud initial conditions is one of the major causes for the spinup problem in explicit cloud and precipitation forecasting models during the first a few hours. Although many studies have sought a remedy by using satellite or/and radar data, the lack of detailed information on initial moisture, cloud water and latent heating fields is still a key problem. NEXRAD data can provide the three-dimensional precipitation field with high spatial and temporal resolution, though in a model, other conventional variables (i.e., water vapor, temperature and wind) may not be consistent with the cloud and precipitation analysis fields. Thus, evaporation processes may quickly kill convective storms present at the start of the model forecast. To address this problem, a diabatic initialization scheme has been improved to provide a latent heat forcing in the model thermodynamic equation and to force vertical circulations and the associated divergence that is c