Summer's Worth of Rain in Two Days... What Caused the 912mm Downpour?

[Anchor]

The record-breaking downpour in South Gyeongsang Province was driven by a low-pressure system formed after Typhoon Dolphin dissipated.

Reporter Jeong Gu-hui explains why such extreme rainfall hit South Gyeongsang Province and how much longer the rain is expected to continue.

[Reporter]

What brought the heavy rain to the South Gyeongsang region today (August 17) was a low-pressure system.

Low-pressure systems rotate counterclockwise in the Northern Hemisphere.

As a result, southwesterly winds blow on the eastern side of the system, acting like a pump pulling up warm water vapor from the south.

Looking at the radar imagery from 2 a.m. today, when heavy rain poured over Geoje, strong southwesterly winds were clearly blowing, feeding rain clouds generated from the South Sea into the southern coast of South Gyeongsang Province.

In particular, these clouds can be seen developing even more intensely the moment they hit Geoje.

What is the reason?

Water vapor is carried inward by the wind.

However, when strong winds move inland, their speed drops sharply due to friction with the ground.

As the inflow speed of the water vapor suddenly slows down, more accumulates than escapes, causing lower-level convergence, which in turn develops intense rain clouds.

Simply put, a bottleneck phenomenon causes the amount of water vapor to surge.

Consequently, Geoje was pounded with 912mm of heavy rain over the past two days, yesterday and today, while Busan received 222mm and Miryang, which had suffered from severe drought, recorded 132mm—showing that precipitation surged closer to the coast.

Geoje's average summer precipitation is 935mm, meaning that an entire summer's worth of rain poured down in just two days.

In addition, the current water temperature along the southern coast is about 28°C (82°F), and the warm sea supplying more water vapor has also been pointed out as a contributing factor.

Furthermore, blocked by a high-pressure system stationed over Japan, the low-pressure system failed to move out to the east and stalled for an extended period, continuously generating rain clouds while remaining under its influence.

As the region is expected to fully break away from the influence of this low-pressure system only by tomorrow (August 18), additional rainfall of up to 60mm is forecasted for the southern coast of South Gyeongsang Province, and up to 30mm for the inland areas of South Gyeongsang and southern North Gyeongsang provinces until tomorrow.

(Video editing: Kim Jin-won, Design: Park Tae-young)
※ Please note: This article was translated by AI and may contain errors.