MET/MODE object analysis of atmospheric integrated water vapor (IWV) or integrated water vapor transport (IVT) fields makes it possible to associate space, time, and intensity attributes to important features (e.g., atmospheric rivers) within the fields. When these fields are produced in model forecasts, the MODE object-attributes can be used to locate times and places along the North American west coast where the likelihood of an extreme precipitation event is high. Obviously the usefulness of these forecasts depends on their uncertainties in all these dimensions. As a measure of this uncertainty we use MODE's built in capability to compare objects from two data fields. Over the northeast Pacific domain we compare 12 hour composites of Special Sensor Microwave/Imager (SSM/I) and Special Sensor Microwave Imager Sounder (SSMIS) IWV observations with global model (GFS) real-time IWV prognostications made for a variety of lead times. In addition, we explore the use of these objects in providing a climatological index indicative of the threat for extreme precipitation along the North American west coast.