Atmospheric River Over the Middle East

Atmospheric Rivers (ARs) are narrow and long bands of high water vapour content, which largely originate in the tropics or subtropics and propagate into mid- and high-latitudes. They can bring beneficial rain and snow but, in particular the most intense, can lead to catastrophic flooding and loss of life. One of such occurrences in the Middle East in mid-April 2023 is investigated using model and observational data. The high-resolution (2.5 km) simulation put in evidence narrow (5-15 km) and long (100-200 km) convective structures within the AR, known as AR rapids, which produced heavy precipitation (>4 mm hr^-1), further enhanced by gravity waves that developed over the high terrain in western Saudi Arabia, and propagated at high speeds (>30 m s^-1). ARs are occurring more frequently in the Middle East as they are globally, and with increased atmospheric water vapour in a warming climate, AR rapids may be even more destructive.