Chicago's position on Lake Michigan creates wind conditions that devastate compromised roofs. Prevailing westerlies accelerate as they cross open water, hitting the city's eastern neighborhoods with sustained gusts that exploit every loose shingle and weakened flashing. Spring derechos bring 70 mph straight-line winds that tear entire roof sections free. Winter lake-effect snow loads stress already-damaged structures until they fail completely. A small leak identified today becomes a collapsed roof deck after the next storm front moves through. Emergency roof tarp installation in Chicago is not about convenience. It is about stopping progressive failure before wind and precipitation turn a repairable problem into a structural loss.