Torrential rain, accompanied by gusts of wind, thunder and lightning, are expected to fall between Aug. 4-5—a complete 180 from last week’s extreme heat. Some areas like Sancheong, South Gyeongsang Province, are still recovering from last month’s devastating rains, but must prepare themselves for severe downpour once again.
According to the Korea Meteorological Administration (KMA), on Aug. 3, the Muan Airport in South Jeolla Province recorded 140.8 millimeters within an hour of rain starting at 7 p.m. This number is on par with the most hourly rainfall recorded in Eocheongdo Island, Gunsan, North Jeolla, last year July at 146 millimeters. On the same day, at around 8 p.m., a man in his 60s was swept away by floodwaters in Hyeon-gyeong-myeon, Muan County—later found in cardiac arrest. As of 10 p.m., Muan Airport had accumulated a total of 289.6 millimeters of rainfall.
The rain is caused by a low-pressure system moving eastward from the western seas, carrying rain clouds over to the Korean peninsula. As the moist air from the North Pacific High collides with the dry air descending from the north, rainbands are expected to grow larger, resulting in a heavier downpour.
This time, the rain is expected to continue until the morning of Aug. 5. Cumulative rainfall between Aug. 3-5 is forecasted to reach 50 to 150 millimeters in the Seoul metropolitan area; 10 to 120 millimeters in Gangwon Province; 30 to 180 millimeters in the Chungcheong region; 50 to 250 millimeters in the Honam region; 20 to 250 millimeters in the Yeongnam region; and 20 to 150 millimeters on Jeju Island. Downpours exceeding 250 millimeters are expected along the southern coast, near Mount Jiri, and in Gwangju and South Jeolla Province.
A KMA representative said, “Water levels in rivers and valleys can cause flashfloods, and with heavy rain anticipated for the night, thorough precautions must be placed.”
Another round of heavy rain may occur further into the week, on Aug. 6-7. It’s forecasted to start on Aug. 6 in the central region and northern part of North Gyeongsang Province, gradually making its way south to the southern regions and Jeju Island by the afternoon. On Aug. 7, rainfall is expected to be concentrated in the southern region and Jeju.
In the summertime, the Korean Peninsula is influenced by the Tibetan High and the North Pacific High, which is centered east of Japan. These two high-pressure systems often fluctuate in strength, so when they expand simultaneously to cover Korea, extreme heat waves, like the one last week, can occur.
As of now, the Tibetan High and the North Pacific High are weakened, placing Korea on the edges of both systems. The Tibetan High in the upper atmosphere brings dry air from the north while the North Pacific High, in the mid-levels of the atmosphere, draws hot, humid air from the south. Overlaps between the two air systems have led to rain bands forming over the peninsula. Typhoon Khanun, which has weakened into an extratropical cyclone, has left its remnants, moving eastward and pulling large amounts of moisture to Korea’s western seas.
Heat advisories were eased or lifted on Aug. 3 as rain brought the temperatures down for most parts of the country—Seoul, Incheon, Daejeon, Daegu, Busan, and Ulsan. However, humidity from the rain is expected to keep the heat from disappearing completely. Apparent temperatures are likely to hover around 33°C in the coming days, keeping conditions hot and sweltering.
Komentar
Posting Komentar