A Tool to Identify Convective Outflows in Numerical Weather Prediction Models for Fire Weather Forecasting

Abrupt changes in wind direction and speed can dramatically impact wildfire development and spread. Additionally, wind speed and direction changes can pose significant problems to firefighting efforts and have been implicated in a number of fatality fires. A frequent driver of such wind shifts is outflow from thunderstorms and organized convective systems, and their identification and prediction present critical challenges for fire weather forecasters. The work presented aims to develop a tool to identify convective outflow boundaries in high-resolution numerical weather prediction (NWP) models to provide guidance for fire weather forecasting. Algorithms and a graphics utility have been developed to objectively identify and display gust fronts and similar boundaries from forecasts of the operational High Resolution Rapid Refresh (HRRR) system. An initial version of the tool shows success in its application to deterministic HRRR forecasts of convective events in both simple and complex terrain, both with and without concurrent wildfire activity. Further development of the capability will allow it to represent probabilistic information about gust fronts generated from high-resolution ensemble NWP systems. This poster describes the tool and presents results for selected cases.