"Monster Heavy Rain" Hits Japan... The Identified Cause: "Hard to Believe"

[Anchor]

Japan's Meteorological Agency also fell short of expectations in terms of forecasting accuracy. They completely failed to predict the record-breaking downpour that left catastrophic damage in Chiba Prefecture last month. The Japan Meteorological Agency explained that the torrential rain was caused by massive cumulonimbus clouds reaching up to 15 kilometers in height, calling it an unprecedented phenomenon.

Correspondent Mun Junmo reports.

[Reporter]

On the night of August 13 last year, sudden torrential rain struck Chiba Prefecture, Japan.

Vehicles were submerged, and villages turned into lakes.

Evacuation orders were issued for 400,000 people, and 13 lives were lost.

The losses from this downpour amount to approximately 100 billion won in our currency.

A total of 348 mm of rain—three times the average rainfall for the entire month of August—poured down in just 12 hours, turning into a "monster downpour" that even the Japan Meteorological Agency did not anticipate.

The Meteorological Research Institute announced the results of its analysis, stating that starting at 5:30 p.m. on the 13th, massive cumulonimbus clouds reaching a height of 15 km developed and hovered over Chiba Prefecture for over six hours.

Such cumulonimbus clouds are of the "squall line type" and typically move quickly due to the wind they generate, but this time was different.

[Adachi / Head of Research Laboratory, Japan Meteorological Research Institute: Since researchers generally know that developed squall-line-type cumulonimbus clouds move quickly, it was hard to believe at first.]

The intensity of the wind generated by the cumulonimbus clouds and the headwind blowing from the Pacific Ocean were similar, causing the clouds to stay in one place for a long time.

As the stationary period prolonged, the falling rain created cold air, which pushed up the warm air near the ground, repeating a process that caused the cumulonimbus clouds to develop even higher.

[Adachi / Head of Research Laboratory, Japan Meteorological Research Institute: It was shocking that a phenomenon with insufficient accumulated research actually occurred and led to such a disaster.]

Even after the rain stops, the Meteorological Agency urged caution as soil collapse accidents, such as landslides near Mt. Fuji, continue to occur due to weakened ground from the prolonged rainfall.

(Camera Reporter: Han Chul-min, Mun Hyun-jin | Video Editor: Yoon Tae-ho | Design: Taeyoung, Kim Yeji)
※ Please note: This article was translated by AI and may contain errors.