Sub-seasonal to seasonal outlook of the 2022-23 southwestern Korea meteorological drought

The southwestern Korean Peninsula had experienced cumulative precipitation deficits from the early spring of 2022, causing a severe meteorological drought in March 2023. As a growing season was forthcoming, the sub-seasonal to seasonal outlook of this ongoing drought came into question. This study aims to investigate a key driver of the ongoing drought and the required precipitation for its termination, and examine the sub-seasonal and seasonal outlooks of the ongoing drought via probabilistic and climate model-based forecasts. Results show a comparable contribution of springtime and summertime precipitation deficits in 2022, indicating that six-month accumulated precipitation deficit of 2022 was a key driver of the ongoing drought. We find that at least 80, 150, and 210 mm (170, 310, and 440 mm) of accumulated precipitation are required for the recovery (full recovery) in March, April, and May 2023, respectively. These required cumulative precipitation are found from 25% and 20% of empirical and dynamic precipitation forecasts, respectively. This study highlights the importance of the collaborative effort of national and local governments and stakeholders on mitigating negative impacts of the ongoing drought.

Automated summary

This study investigates the meteorological drought caused by cumulative precipitation deficits in the southwestern Korean Peninsula since early spring 2022 and predicts the sub-seasonal and seasonal outlooks of the drought using probabilistic and climate model-based forecasts. The results show that both springtime and summertime precipitation deficits in 2022 contribute equally to the ongoing drought, with the six-month accumulated precipitation deficit being a key driver. At least 80, 150, and 210 mm of precipitation are required for recovery in March, April, and May 2023, respectively.