A regional ensemble forecast system for stratiform precipitation events in northern China. Part I: A case study
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A single-model, short-range, ensemble forecasting system (Institute of Atmospheric Physics, Regional Ensemble Forecast System, IAP REFS) with 15-km grid spacing, configured with multiple initial conditions, multiple lateral boundary conditions, and multiple physics parameterizations with 11 ensemble members, was developed using the Weather and Research Forecasting Model Advanced Research modeling system for prediction of stratiform precipitation events in northern China. This is the first part of a broader research project to develop a novel cloud-seeding operational system in a probabilistic framework. The ensemble perturbations were extracted from selected members of the National Center for Environmental Prediction Global Ensemble Forecasting System (NCEP GEFS) forecasts, and an inflation factor of two was applied to compensate for the lack of spread in the GEFS forecasts over the research region. Experiments on an actual stratiform precipitation case that occurred on 5–7 June 2009 in northern China were conducted to validate the ensemble system. The IAP REFS system had reasonably good performance in predicting the observed stratiform precipitation system. The perturbation inflation enlarged the ensemble spread and alleviated the underdispersion caused by parent forecasts. Centering the extracted perturbations on higher-resolution NCEP Global Forecast System forecasts resulted in less ensemble mean root-mean-square error and better accuracy in probabilistic quantitative precipitation forecasts (PQPF). However, the perturbation inflation and recentering had less effect on near-surface-level variables compared to the mid-level variables, and its influence on PQPF resolution was limited as well.
Key wordsshort-range ensemble forecast rain enhancement operation probabilistic forecast
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- Du, J., G. DiMego, M. S. Tracton, and B. Zhou, 2003: NCEP short-range ensemble forecasting (SREF) system: Multi-IC, multi-model and multiphysics approach. Research activities in atmospheric and oceanic modelling, J. Côté, Ed., Report 33, CAS/JSC Working Group Numerical Experimentation (WGNE), WMO/TD-No. 1161, 5.09–5.10.Google Scholar
- Kong, F., and Coauthors, 2007b: Preliminary analysis on the real-time storm-scale ensemble forecasts produced as a part of the NOAA hazardous weather testbed 2007 spring experiment. Preprints, 22th Conf. on Weather Analysis and Forecasting and 18th Conf. on Numerical Weather Prediction, Amer. Meteor. Soc., Park City, UT, 3B.2.Google Scholar
- Kong, F., and Coauthors, 2008: Real-time storm-scale ensemble forecast 2008 Spring Experiment. 24th Conf. Several Local Storms, Savannah, GA, Amer. Meteor. Soc., Paper 12.3.Google Scholar
- Kong, F., and Coauthors, 2009: A real-time storm-scale ensemble forecast system: 2009 Spring Experiment. 23rd Conf. Weather Analysis and Forecasting / 19th Conf. Numerical Weather Prediction, Omaha, NB, Amer. Meteor. Soc., Paper 16A.3.Google Scholar
- Shen, Y., M. Feng, H. Zhang, and F. Gao, 2010: Interpolation methods of China daily precipitation data. J. Appl. Meteor. Sci., 21, 279–286.Google Scholar
- Skamarock, W., J. Klemp, J. Dudhia, D. Gill, D. Barker, W. Wang, and J. Powers, 2005: A description of the Advanced Research WRF Version 2. NCAR Technical Note TN-468+STR, 88pp.Google Scholar
- Wei, M., Z. Toth, R. Wobus, and Y. Zhu, 2008: Initial perturbations based on the ensemble transform (ET) technique in the NCEP global operational forecast system. Tellus A, 60, 62–79.Google Scholar
- Xue, M., 2007: CAPS realtime storm-scale ensemble and high-resolution forecasts as part of the NOAA hazardous weather testbed 2007 spring experiment. 22nd Conf. Weather Analysis and Forecasting/18th Conf. Numerical Weather Prediction., Amer. Meteor. Soc., Park City, UT, Paper 3B.1.Google Scholar
- Xue, M., 2008: CAPS realtime storm-scale ensemble and high-resolution forecasts as part of the NOAA Hazardous Weather Testbed 2008 Spring Experiment. Preprints, 24th Conf. on Severe Local Storm, Amer. Meteor. Soc., Savannah, GA, Paper 12.2.Google Scholar
- Xue, M., 2009: CAPS realtime storm-scale ensemble and high-resolution forecasts for the NOAA Hazardous Weather Testbed 2009 Spring Experiment. 23rd Conf. Weather Analysis and Forecasting/19th Conf. Numerical Weather Prediction, Omaha, NB, Amer. Meteor. Soc., Paper 16A.Google Scholar
- Zhu, Y., and Z. Toth, 2008: Ensemble based probabilistic forecast verification. Preprints, 19th Conf. on Probability and Statistics, New Orleans, LA, Amer. Meteor. Soc.Google Scholar