South Korean weather forecasters warn of nationwide strong rain and wind on May 26, 2026, with extreme conditions expected in southern regions [1].
These forecasts indicate a high risk of flash flooding and infrastructure damage, particularly in coastal areas where rainfall intensity is expected to peak. The severity of the predicted storm may necessitate emergency preparations for residents and local governments.
KMA analyst Lee Kwang-yeon said a low-pressure system moving from the southwest is pulling hot, humid air into the Korean peninsula [1], [4]. This system is interacting with a high-pressure area to the east, creating a pressure gradient that intensifies both wind speeds and rain clouds [1], [4].
Jeju Island and the southern coastal region, known as the Namhae area, are expected to be hit hardest [1], [3]. Forecasters predict extreme heavy rain in these zones, with hourly rainfall reaching up to 50 mm per hour [1].
Lee said that Jeju Island and the southern coast will be affected by a lower-level jet due to the pressure gradient between the southwestern low and southeastern high. He said that very strong and heavy rain, at a level requiring heavy rain warnings, is expected [2].
An anchor for YTN said that strong rain and wind are expected nationwide on May 26 [2]. The meteorological activity is driven by the specific atmospheric instability caused by the converging pressure systems [1], [4].
“Very strong and heavy rain, at a level requiring heavy rain warnings, is expected.”
The convergence of a southwestern low-pressure system and a southeastern high-pressure system creates a volatile atmospheric environment. When this gradient is coupled with a lower-level jet, it often results in concentrated, high-intensity precipitation. For South Korea, this means the southern coast and Jeju Island are susceptible to 'extreme rainfall' events that can overwhelm drainage systems and trigger landslides in mountainous terrain.
