7B.7 Inter-comparison of AFWA operational configurations using WRFv3.3.1 and WRFv3.4

Xu, Mei, Jamie Wolff, and Michelle Harrold, National Center for Atmospheric Research

To assess the performance of WRF as it progresses from version 3.3.1 to version 3.4, the Developmental Testbed Center (DTC) performed testing and evaluation with the Advanced Research WRF (ARW) dynamic core for the two versions of the WRF. The test was conducted in a functionally similar operational environment to Air Force Weather Agency (AFWA) operations, where each configuration was initialized with output from AFWA’s Land Information System (LIS) as well as a 6-hour "warm start" spin-up utilizing the respective version of WRF Data Assimilation (WRFDA). The two model configurations also used the same physics options and were run over the same set of cases, allowing for a direct assessment of how performance changes as the WRF version number increases from 3.3.1 to 3.4. The test cases span a 12-month period from 1 July 2011 to 30 June 2012, with forecasts being initialized every 36 hours. This extensive testing period allows for robust results as well as the ability to investigate seasonal performance of the configurations. Evaluation of traditional verification metrics for surface and upper air variables, along with an assessment of statistical and practical significance will be presented.