What phenomenon occurs when wind rolls around and comes up the other side, exposing both sides of a structure?

The phenomenon described is known as a leeward eddy. This occurs when wind interacts with a structure, creating turbulent air patterns. As the wind wraps around the structure, it can lead to swirling air currents that may increase the exposure of both sides of the structure to heat, firebrands, or embers during a wildfire event. The leeward side, being sheltered from the direct wind, can still experience a buildup of heat and embers brought around by these eddies, increasing the risk of ignition.

The other terms provided do not capture the specific dynamics of wind behavior around a structure. Defensible space refers to the area surrounding a building where vegetation has been managed to reduce fire risk, while natural pathways pertain to the geographical features that can affect fire spread. Fire intensity measures the heat output of a fire and does not address the wind patterns that create the leeward eddy effect. Therefore, understanding leeward eddy dynamics is essential for wildfire mitigation efforts, particularly in assessing the risks to structures during fire events.