Sources of uncertainty in adaptive systems are rarely independent, and their interaction can affect the attainment of system goals in unpredictable ways. Despite ample work on “taming” uncertainty, the research community has devoted little attention to the systematic representation, analysis, and mitigation of uncertainty propagation and interaction (UPI) in adaptive systems. To address this oversight, we introduce Uncertainty Flow Diagrams, a notation that captures key UPI aspects. We demonstrate the use and benefits of our novel notation on Znn.com, an adaptive news site infrastructure.