Convection-Allowing Analysis and Prediction of Hurricane Joaquin (2015) through the EnKF Assimilation of GOES-13 Infrared Satellite Radiances

The geostationary GOES-13 satellite, formerly known as GOES-N or GOES-EAST, has been operated operationally by NOAA since 2010. It provides high temporal and spatial infrared radiance data over the open oceans that are crucial for the tropical cyclone monitoring but so far have not been routinely and directly assimilated into numerical weather prediction models to improve hurricane forecasts. This study for the first time explores direct assimilation of GOES-13 infrared radiance into a convection-allowing hurricane analysis and forecasting system. Using the PSU WRF-EnKF data assimilation system, a series of continuously cycling experiments were performed to examine the impacts of assimilating GOES-13 infrared radiances on the prediction of Hurricane Joaquin (2015), a major Atlantic hurricane that was difficult to forecast in real-time by operationally models in terms of both track and intensity, in particular during the genesis and early development stages. Immediate positive impact on the forecast performance was obtained right after the WRF-EnKF assimilates the first batch of GOES-13 radiance. Continuous cycling assimilation of more and more satellite observations every 3 hours led to further improvement in both the analysis and forecasts. The intensity forecast error on average over the life cycle of the event was reduced by as much as 50% for lead times up to 5 days compared to WRF-EnKF experiment that assimilates only non-radiance observations. Currently we are exploring the use of different filter configurations and different channels and applications to different events to more systematically explore the potential of assimilating geostationary infrared radiance for hurricane prediction, and in preparation for future assimilation of GOES-R (GOES-16) infrared radiances.