Quantitative and Probabilistic Volcanic Ash Forecasting for Aviation

We present highlights of recent efforts to design an operational workflow to produce probabilistic and quantitative volcanic ash forecasts for aviation. The work utilizes the HYSPLIT atmospheric transport and dispersion model, NOAA’s global ensemble forecast system (GEFS), and observations from the VOLcanic Cloud Analysis Toolkit (VOLCAT) for data fusion and forecast verification. The workflow includes source determination using an inversion algorithm, data insertion methods, and forecast verification of the probabilistic forecasts. Several case studies of ash emissions will be discussed including eruptions of Bezymianny in October of 2020, Mauna Loa in November 2022, Sheveluch in April 2023, and Popocatepetl in April 2023.