Blow-up fire behaviour is characterised by a sudden and considerable increase in either the wildland fire intensity or spread rate, and is often accompanied by extreme pyro-convection. Blow-up fires are currently difficult to predict, due in part to a poor understanding of environmental factors that contribute to blow-up fire behaviour, and therefore pose a serious risk to firefighters and civilians. Low-level jets (LLJs) are a common feature of the atmospheric boundary layer (ABL) during blow-up fires¹. Recent work utilised the Advanced Regional Prediction System (ARPS) numerical weather prediction model, which included an imposed steady-state heat flux emulating a wildland fire², to numerically investigate the feedback of LLJs on the pyro-convective plume and downwind ABL properties. That numerical investigation established that the pyro-convective plume and downwind ABL properties are highly sensitive to variations in the LLJ properties, including the jet height, intensity and vertical wind shear above the jet. This study expands on that recent work through improved spatial and temporal resolution, and a more realistic geometrical representation of a wildland fire, within ARPS. The analysis presented examines the sensitivity of the near-fire convergence, and the downwind turbulent kinetic energy and vorticity, to LLJ properties. The results indicate that there are several physical mechanisms by which LLJs may commonly be associated with blow-up fire behaviour, including spotting and downwind pre-heating of vegetation.