Fire responders and local authorities face significant challenges when dealing with extreme wildfires. These fires are unpredictable and exhibit varying spread rates and plume structures depending on whether the fire regime is plume-driven or wind-driven. To better predict fire spread in these uncertain scenarios, it is crucial to gain a deeper understanding of the drivers of the fire regime. Here, we examine the Froude Number to predict the plume structure and fire spread rate using idealized simulations run with the Weather Research and Forecasting (WRF) model. Changing levels of relative humidity in the atmosphere as well as different fuel types can provide further insight into how fire spreads in varying conditions. The intensity of wildfires has greatly increased over the past several years and that trend is predicted to continue in the near future. By improving predictions of fire spread and plume structure during wildfire events, our results directly help the work of firefighters, potentially leading to less infrastructure damage and more lives saved.