Forecast and Evaluation of High-Aerosol Events Using Operational Global Forecast Models at NOAA/National Weather Service

Severe biomass burnings, dust plumes or anthropogenic pollution over urban areas have led to high aerosol events, where in the aerosol optical thickness (AOT) greater than 0.5 have been observed. Such events have large regional and global impacts. Reliable predictions of such events on short (1-3days) to medium (3-5days) time range may reduce potential risks and harms to public health as well as disruption to economics. Operational global aerosol forecast system produced at NOAA/National Weather Service includes AOT, three dimensional mixing ratios of aerosol species for every 3 hour upto 5days. Currently NOAA is testing the predictions driven by the operational version of the Global Forecast System (GFS) that includes the Finite-Volume-Cubed-Sphere (FV3) dynamical core since early 2019. FV3GFS was coupled online with aerosol modules from Goddard Chemistry Aerosol Radiation and Transport model (GOCART) as well as a biomass burning plume rise model from WRF-Chem that will replace the current operational global aerosol prediction NGAC system at NCEP (planned in 2020). It will be placed as an ensemble member in the Global Ensemble Forecast System (GEFS), and named as GEFS-aerosols. In this study we selected few such high AOT events in the past year, that include biomass burning events (over North America, South Africa), Saharan and Middle East dust outbreaks. We evaluated both current operational and future configurations AOT against available ground, satellite and other center model predictions using standard meteorological statistics over short (6-18 hours), medium (36-48 hours) and long range (60-72 hours) forecasts prior to these events. We will overview these evaluation results in this presentation.