A useful method of modeling threats from hazards and documenting their disaster causation sequences is called “cascading threat modeling.” This type of modeling enables emergency planners to address hazard and risk assessments systematically. This paper describes a cascading threat modeling and analysis process. Wildfire and an associated postburn flash flood disaster are modeled to serve as examples of the modeling and analysis process. Models are developed for both wildfire and flash flood, and the two models are then linked at a particular threat interface. Additionally, the use of a Federal and State Interagency Technical Team (IAT) for onsite wildfire and postburn flash flood assessment is described. The integration of expert field knowledge held by IAT specialists and agency staff is an essential component in developing credible cascading disaster models. When applied to local hazard mitigation planning, a detailed and systematic picture of local threat, risk, vulnerability, and consequence arises. An example wildfire burn and postburn flash flood is provided as a reference. Additionally, the use of an IAT for onsite wildfire and postburn flash flood assessment is described because this kind of field knowledge is essential in developing credible cascading disaster models.