The Warn-on-Forecast System Demonstration at the Aviation Weather Center

The Warn-on-Forecast System (WoFS) is a rapidly updating storm-scale ensemble that employs rapid assimilation of radar and satellite data to enable near-term (0–6 h) probabilistic forecasts of individual thunderstorms. WoFS development was motivated by needs in severe weather watch and warning operations. A similar need to confidently predict individual thunderstorms and their hazards extends to other applications. The National Severe Storms Laboratory (NSSL) and National Weather Service (NWS) Aviation Weather Center (AWC) conducted a four-week demonstration during summer 2024 to explore the possible application of WoFS to aviation weather forecasting. Two regional WoFS domains were run in the vicinity of major airports in the contiguous United States on 19 days in June and July. NWS forecasters at AWC, Center Weather Service Units (CWSU), and Weather Forecast Offices (WFO) provided feedback through testbed activities, a real-time and asynchronous chat room, shift shadowing, and post-event surveys. The demonstration revealed common aviation-related forecast tasks regarding convective weather, and the WoFS products that were most frequently used to aid those tasks. These themes emerged through the various feedback mechanisms and included several illustrative real-world use cases. The demonstration also identified potential hindrances to operational use, such as the cadence of WoFS forecasts relative to existing workflows at AWC. Staffing challenges and workload at CWSUs also hindered the ability of their meteorologists to provide feedback, suggesting future data-gathering efforts involving CWSUs should be co-designed and deliberate.