An Evaluation of Physics Enhancements within Hurricane WRF

The Hurricane Weather Research and Forecasting (HWRF) model is a fully coupled atmosphere-ocean model run operationally for all global basins.  In recent years, the hurricane community has invested a substantial amount of effort to investigate and improve the representation of physical processes in the HWRF model.  The Developmental Testbed Center (DTC) has partnered with the NOAA/NCEP Environmental Modeling Center (EMC) Hurricane Team and hurricane physics developers to evaluate HWRF physical parameterizations directed at improving HWRF forecast skill.

For this evaluation, retrospective HWRF forecasts for several storms in the Atlantic and Eastern Pacific basins will be produced using variations of the 2016 operational configuration; with results compared against the operational baseline. The variations will be tested as packages of improvements including multiple individual scheme changes to partially alleviate compensatory errors, where improvements to a specific scheme may result in little to no forecast improvement due to prior tuning of another related scheme (e.g. radiation and cloud microphysics).  Specifically, we will discuss results related to recommended enhancements from developers to microphysics, PBL, and radiation parameterizations. Assessment will be done through a combination of physical process diagnostics as well as traditional track and intensity verification, including statistical significance.  Additionally, verification of large-scale fields and storm scale evaluation will be explored to further investigate HWRF physics sensitivities.