This book draws on a two-year ethnography of forecasting operations at the National Weather Service (NWS) to theorize decision-making in action. Contrary to popular wisdom, weather forecasters are considerably better than most other so-called expert decision-makers at mastering uncertainty. Following them in their quest for ground truth, therefore, promises to hold the key to the analytically elusive process of diagnosis and prognosis as it actually happens. That is the ultimate objective of this book—by systematically excavating how weather forecasters achieve a provisional coherence in the face of deep uncertainty, how they harness diverse information to project themselves into the future, it endeavors to develop a better conceptual framework for studying uncertainty management in action. Accordingly, the six empirically substantive chapters of the book illuminate key aspects of the process of meteorological decision-making at the NWS: the institutionalized socio-technical environment in which forecasters operate, the forecast production routine; the distillation of atmospheric complexity; the negotiation of accuracy and timeliness in the face of hazardous weather and after a missed forecast; the organization of future anticipation at different time horizons; the tradeoffs of offering expert advice to multiple audiences. The proposed conceptual framework provides the analytic tools to maintain sustained attention to the stable cultural and broader social field of decision-making practice but without losing sight of the situationally-driven micro-context of action and interaction. It reinstates decision-makers as makers of decisions, creatively implementing institutional goals in locally rational ways in order to fashion a workable solution to the decision-making task at hand.