A highlight of the program was Caren Marzban's (University of Washington/University of Oklahoma) investigation of the application of a cluster analysis technique to verify high-resolution precipitation forecasts. The left panels illustrate the methodÃs identification of clusters in the observed (top panel) and forecast (bottom panel) precipitation fields and the matching of these clusters (color coding). The right panel shows an example of Critical Success Indexes obtained through the application of this method to actual forecasts generated for the WRF Spring Program
Priority 2: Building Capacity for Coping with Weather and Climate Hazards
Developmental Testbed Center
Background
The Developmental Testbed Center (DTC) is a national facility created in 2003 to facilitate the interaction of the operational and research communities in accelerating the improvement of numerical weather prediction (NWP) for the U.S. The DTC effort at NCAR includes:
- A program for testing and evaluating various WRF model configurations so that the operational community can plan for changes and upgrades to the operational models and the research community has access to the latest NWP systems for testing and research.
- A visitor program that invites members from the operational and research communities to participate in the testing and evaluation of WRF.
- A user support system that provides documentation, tutorials, and helpdesk capabilities to aid users in both the research and operational communities in accessing and using WRF codes.
Progress
WRF Core Test
The current WRF Software Framework supports two dynamical solvers: the Advanced Research WRF (ARW) developed by NCAR, and the Nonhydrostatic Mesoscale Model (NMM) developed by NCEP. In 2006 a controlled comparison of these two dynamical solvers was conducted using intensive retrospective testing with two separate physics suites. The parallel runs were then evaluated using rigorous, objective verification measures which indicated that the AWR and NMM produce forecasts with comparable skill. The dynamical core with the smallest error depends on both the field under consideration (i.e., winds, temperature, relative humidity and precipitation) and the level in the atmosphere or the threshold for precipitation accumulation.
The DTC Visitor Program funded ten visitors in FY06 to study physics parameterizations, data assimilation, and new verification. Summaries of these projects are posted on the DTC website.
The DTC conducted two WRF-NMM Tutorials during FY06, providing lectures on the pre-processor, model, and post-processing tools, as well as practical sessions that allowed participants to gain hands-on experience building and running each component of the end-to-end system. The tutorial participants represented a broad cross-section of both the national and international community.
Plans
With a recent increase in funding from AFWA, the DTC will begin to assemble a state-of-the-art verification system. The ARW and NMM tutorials will be merged into a single WRF tutorial which will be offered twice in 2007. DTC maintenance of the WRF Reference Code will include a series of careful tests to establish baseline verification statistics for all Reference Code components and interoperability between all components. Code management will be a new task for the DTC. The DTC will set up the full NCEP North American Model system (minus the data assimilation component) on the DTC computing platforms in order to make the operational system available to the community for testing and evaluation.
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