On the role of sea surface temperature variability in southern Arabian Peninsula extreme rainfall on 16th April 2024

The United Arab Emirates (UAE) experienced unprecedented rainfall on 16th April 2024, with Al-Ain recording 254 mm and Dubai 142 mm in a single day, driven by a Mesoscale Convective System (MCS). This extreme event resulted from the interaction of cold air from higher latitudes pushed eastward by the subtropical jetstream with warm, moist air from the Arabian Sea. The unusually high sea surface temperature (SST) in the Arabian Sea, reaching 30.5°C (1°C above the 40-year average), was influenced by El Niño and one of the strongest positive Indian Ocean Dipole episodes on record, which enhanced evaporation and atmospheric moisture content. 

 

To investigate the role of anomalous SSTs, we conducted two numerical experiments using the Weather Research and Forecasting (WRF) model: one with the actual 2024 SST conditions from ERA5 and another with 1981-2020 SST climatology. Time series and probability density function analyses revealed that extreme rainfall was more widespread in the 2024-SST simulation compared to the climatology, with higher precipitable water content (40–60 mm) observed in the former, a range rarely seen in the latter. Further analysis of moisture transport and equivalent potential temperature confirmed that the warm SST-induced moisture played a pivotal role in driving the enhanced transport and heavy precipitation. 

 

These findings underscore the critical role of anomalously high SSTs in intensifying extreme rainfall events, highlighting the need for improved predictive models and resilient infrastructure to mitigate the growing risks posed by climate change in the region.