South Korea's central-western region expects strong, prolonged heavy rain over the next two days, according to meteorological forecasts [1].

These weather patterns pose a significant risk of flash flooding and infrastructure damage as the region oscillates between extreme heat and intense precipitation. The concentration of rainfall in a short window can overwhelm drainage systems and increase the likelihood of landslides in hilly terrain.

Kim Seung-bae, head of the Korean Natural Disaster Association, said the severity of the expected weather during a broadcast interview [1]. He said that rainfall levels of 150 mm or more are considered very heavy concentrated rain [2].

There is a discrepancy in the reported maximum rainfall totals. While broadcast anchors cited forecasts of over 1,500 mm [1], Kim said 150 mm is a threshold for very heavy rain [2]. This range suggests a high degree of volatility in the projected storm intensity.

Kim said the official standards used by the Korea Meteorological Administration to issue heavy-rain warnings. A warning is typically triggered when 90 mm of rain falls within three hours, or 180 mm falls within 12 hours [3].

Residents in the central-western area are advised to monitor local alerts as the weather shifts. The combination of heat and sudden heavy rain — known as 'jangmabi' — often creates unstable atmospheric conditions that can lead to unpredictable storm cells [1].

“Rainfall of 150 mm or more is considered very heavy concentrated rain.”

The volatility in rainfall forecasts, ranging from 150 mm to 1,500 mm, underscores the unpredictability of the current monsoon season. Because the Korea Meteorological Administration uses strict hourly thresholds for warnings, the rapid accumulation of water in the central-western region could lead to sudden, high-level alerts that require immediate public evacuation and emergency response.