P31 An evaluation of cloud-radiation enhancements within the 2016 Hurricane WRF system

Newman, Kathryn, National Center for Atmospheric Research (NCAR), Evan Kalina, National Oceanic and Atmospheric Administration (NOAA)/Global Systems Division (GSD) and Cooperative Institute for Research in the Environmental Sciences (CIRES)/ University of Colorado (CU), Mrinal Biswas, NCAR, James Frimel, NOAA/GSD and Cooperative Institute for Research in the Atmosphere (CIRA)/ Colorado State University, Laurie Carson, NCAR, Ligia Bernardet, NOAA/GSD and CIRES/CU, Greg Thompson, NCAR, Michael Iacono and John Henderson, Atmospheric and Environmental Research (AER)

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 physics parameterizations directed at improving HWRF forecast skill.

For this presentation, advancements in cloud-radiation processes within RRTMG will be highlighted for the 2016 operational HWRF system. Results from a new cloud overlap methodology (exponential random) and modifications to the existing partial cloudiness scheme will be compared against the 2016 operational baseline. Retrospective forecasts for several storms in the Atlantic and Eastern Pacific basins will be evaluated through traditional track, intensity, and storm size verification, including statistical significance. Additionally, HWRF-simulated brightness temperatures verified against GOES-13 satellite observations will be shown to further investigate HWRF physics sensitivities. The outcome of the evaluation in the context of the 2017 operational HWRF system will be discussed.