5.3    CAPS Storm-Scale Ensemble Forecasts for the NOAA HWT 2012 Spring Experiment: New features and Ensemble QPF Evaluation

Kong, Fanyou, Center for Analysis and Prediction of Storms, University of Oklahoma, Ming Xue, Center for Analysis and Prediction of Storms and School of Meteorology, University of Oklahoma, and co-authors

The 2012 NOAA HWT Spring Experiment runs from May 07 to June 08, 2012. Since 2007, CAPS provides storm-scale ensemble forecasting (SSEF) products to the annual HWT Spring Experiment.  Unlike past years, the 2012 CAPS SSEF runs twice daily, adding a 1200 UTC initiation, with 15-member 36-h baseline ensemble forecasts. The 0000 UTC initialized SSEF consists of 28 multi-model multi-physics ensemble members using four NWP modeling systems (WRF-ARW, WRF-NMM, ARPS, and COAMPS). The 1200 UTC addition of ensemble allows the assessment of skillfulness of morning initiation against 0000 UTC initiation to the severe storm probabilistic guidance. New in 2012 is the simulated GOES satellite IR channel brightness temperatures computed from three different radiative transfer models (RTMs) including RTMs from NESDIS/JCSDA Community Radiative Transfer Model (CRTM), CIRA, and CIMMS, respectively.  Probabilities and ensemble means of these simulated synthetic GOES-R infrared imagery are generated in realtime as part of upgraded real-time post-processing package in supporting the GOES-R Proving Ground Project.  The experimental convection initiation (CI) and lightning threat products are refined/recalibrated based on evaluations from 2011 Spring Experiment dataset. The WRF newly added stochastic kinetic-energy backscatter (SKEB) perturbation option is applied to a small group of members to allow evaluation of its impact to the SSEF performance at convection-permitting grid resolution. New products, comparison of 00 and 12 UTC ensemble forecasts skill, and other SSEF performance evaluation will be presented on the Workshop.