Evaluating supplemental relationships between convective forecast products for aviation

Current air traffic operations involving convective weather require making strategic planning decisions (2-h to 6-h lead times) at 11, 13, and 15 UTC planning points. Air traffic operations use weather information at these planning points to issue airspace flow programs (AFP), ground delay programs (GDP), and other route advisories. As the NAS becomes increasingly complex, additional forecasts that may provide more structural information are being evaluated to supplement the current operational baseline, the Collaborative Convective Forecast Product (CCFP). Forecasts that provide deterministic structure (simulated radar reflectivity) and probabilistic information are potential supplements to CCFP. Evaluating a product in a supplemental fashion is primarily accomplished through the use of a four-quadrant joint probability distribution (JPD) analysis between the operational product and the candidate supplemental forecast. Two of the quadrants indicate forecast agreement (both forecasts indicate the occurrence of an event and both forecasts indicate the absence of an event) and two of the quadrants represent disagreement (one forecast indicates an event and the other indicates the absence of the event). Quantifying these quadrants by different techniques will be described herein and a candidate product for supplemental use, the Localized Aviation MOS Program (LAMP) thunderstorm probability field will be used as an example.