Atmospheric River Rapids And Their Role In The Extreme Rainfall Event Of April 2023 In The Middle East

The mesoscale dynamics of a record-breaking Atmospheric River (AR) that impacted the Middle East in mid-April 2023 and caused property damage and loss of life are investigated using model, reanalysis and observational data. The high-resolution (2.5 km) simulations revealed the presence of AR rapids, narrow and long convective structures embedded within the AR that generated heavy precipitation (>4 mm hr−1) as they moved at high speeds (>30 m s−1) from northeastern Africa into western Iran. Gravity waves triggered by the complex terrain in Saudi Arabia further intensified their effects. Given the rising frequency of ARs in this region, AR rapids may be even more impactful in a warming climate, and need to be accounted for in reanalysis and numerical models.