Global Probabilistic Forecasts of Convective Weather Aviation Hazards

The Ensemble Prediction of Oceanic Convective Hazards (EPOCH) system, a multi-model-ensemble (MME) prediction system, has been developed to address next generation ICAO-sanctioned requirements for probabilistic forecasts of aviation weather hazards. The forecast guidance provided will support, in part, strategic planning for transoceanic flights with lead times of up to 36 hours, which is needed for long-haul flights. Currently, EPOCH produces bias-corrected probabilistic forecasts of convection, and cloud-top heights exceeding 30 kft. A hybrid system combining the forecasts generated from World Area Forecast Center (WAFC) – London and WAFC – Washington will serve as the eventual operational system for the World Area Forecast System (WAFS).

This presentation will provide updates from our R&D activities related to advancing current methodologies for calibrating and combining MME forecasts. Recent work includes moving to higher-resolution spatial and temporal grid spacing and developing approaches to bias-correcting forecasts north of 60N, the current limit of the forecast system geographic coverage due to observational data availability (i.e. CMORPH) that is needed for bias-correction. For the latter, we use lightning observations to arrive at estimates for a bias-correction factor and touch on the resulting performance. We will also discuss forecast performance (reliability, resolution, sharpness, and value) along typical long-haul flight routes using the Convection Diagnosis Oceanic (CDO) product for verification and an effort to translate ensemble-based weather hazards into potential impacts using an object-based technique.

Disclaimer: This research is in response to requirements and funding by the Federal Aviation Administration (FAA). The views expressed are those of the authors and do not necessarily represent the official policy or position of the FAA.