Impact of airborne radio occultation observations on short term precipitation forecasts of an Atmospheric River

Ten WC‐130J weather reconnaissance aircraft equipped with Global Navigation Satellite System airborne radio occultation (ARO) technology provide additional data on the broader AR environment, specifically as the AR approaches the coastline. This study evaluates the impact of assimilating ARO bending angle observations using the Model for Prediction Across Scales—Atmosphere—Joint Effort for Data assimilation Integration (MPAS‐JEDI).

Experiments use the Local Ensemble Transform Kalman Filter and Three‐Dimensional Ensemble‐Variational algorithms. The control experiment assimilates only global conventional data, while the other experiments incorporate additional ARO observations. The results show that ARO assimilation corrects moisture, temperature, and wind fields, and reduces the error in the integrated vapor transport forecast at landfall.