Pakistan Floods in 2010 and 2022: The Impact of Extratropical Factors on Monsoon Systems

Abstract

Pakistan experienced two major flood events in July 2010 and July–August 2022, resulting in over 1,500 fatalities. The 2010 floods primarily affected Northern Pakistan, while the 2022 floods severely impacted Southern Pakistan. This study examines rainfall patterns, moisture transport, and their connection to European heatwaves and blocking highs. In 2022, unprecedented rainfall in Southern Pakistan contrasted with the northern-focused rainfall in 2010. An intense cycle of low-pressure systems in 2022 transported moist air from the Indian Ocean, facilitated by southeasterly and southerly winds, and triggered deep convection, while in July 2010, southerly winds were dominant. Rossby wave breaking events in late July 2010 and late August 2022 caused the southward movement of upper-level vorticity perturbations, leading to heavy rainfall. Additionally, the heavy rainfall in Southern Pakistan in late August 2022 was influenced by concurrent intense low-pressure systems.