The Developmental Testbed Center Winter Forecasting Experiment (DWFE)

The Developmental Testbed Center (DTC) is a facility where the Numerical Weather Prediction (NWP) research and operational communities interact to accelerate testing and evaluation of new models and techniques for research applications and operational implementation. One method of testing and evaluation employed by the DTC is real-time forecast experiments, such as the DTC Winter Forecast Experiment (DWFE) which ran from January to March 2005. DWFE, which was designed in close consultation between operational forecasters, researchers and DTC staff, was motivated by the needs of the National Weather Service (NWS) for improved model guidance to support their winter weather forecast and warning mission. The objectives of DWFE are to:

œ Evaluate the value of high-resolution NWP forecasts over a large domain during the winter to determine whether operational forecasters find the high-resolution precipitation forecasts useful,

œ Identify whether small-scale flow features resolved by the high-resolution grids have forecast value,

œ Evaluate the relative value of high-resolution deterministic forecasts to the lower resolution ensemble forecast techniques,

œ Evaluate current NWP models and determine where further model research is required.

DWFE employed an end-to-end forecast system with the following components: data pre-processor, forecast model, post-processor, product dissemination, forecast verification, and archival. For this experiment, forecasts were generated daily (00 UTC cycle) using two dynamic cores within the Weather Research Forecast (WRF) framework: the Nonhydrostatic Mesoscale Model (NMM) developed by NCEP was run at NOAA/FSL and the Advanced Research WRF developed by NCAR was run at NCAR. The NCEP post-processor software was used to generate products for these forecasts that were disseminated to NWS forecasters through AWIPS and FX-NET. Pre-generated images were also provided to NWS forecasters and the general community through the DTC website. Evaluation of the DWFE forecasts involved subjective feedback from NWS forecasters, as well as the general community via feedback forms offered on the web. Objective evaluation of these forecasts is based on verification statistics computed using NCEP's verification software and FSL's Realtime Verification System (RTVS). This presentation will describe the DWFE setup, as well as verification statistics, which will be discussed in terms of how the DWFE forecasts compare with the operational ETA model.