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7.5km diameter is definitely a typo, it's supposed to be 7.5m. 11cm of rain per hour is not a typo. The Pacific Ocean contains more water than the rest of the

by kijin 12y ago

7.5km diameter is definitely a typo, it's supposed to be 7.5m. 11cm of rain per hour is not a typo. The Pacific Ocean contains more water than the rest of the oceans combined, and it can dump it wherever the hell it wants. East and Southeast Asia are particularly vulnerable because the trade winds blow hot moisture toward Asia (and away from the Americas). During the monsoon or when a big typhoon hits, some locations can get more than 10cm of rain per hour, although it's usually localized to a small area and only lasts a few hours. Just a couple of weeks ago, a typhoon hit Jeju island in South Korea and dumped 1 meter of rain in 24 hours. That would be more than an entire year's worth of rain in most parts of Europe and North America, and would have been catastrophic if not for the highly porous volcanic geology of Jeju. The current record for South Korea is around 15cm per hour. Since Japan gets more typhoons than we do, I wouldn't be surprised if their record was even higher.

cdr 12y ago
Localized precipitation can be unbelievable when a front stalls over an area, no major event like a typhoon / hurricane even required. The September 2013 floods in the front range of Colorado caused by a stalled front topped out at 9.6mm/hour on the worst day, with 430 mm total in 6 days - just under the average annual precipitation.
- kijin 12y ago
  9.6mm/hr is an order of magnitude lower than what this Japanese reservoir is expected to handle. It would be considered heavy rain, but not at all unusual, for monsoon season in East Asia. It happens a few times every summer, so most cities in Japan and Korea are equipped to handle it just fine. If such events were more common in Colorado, they would have been better prepared, too.
- kijin 12y ago
  Well, turns out you're right that there's no need for a typhoon in order to produce 100mm/hr of rain. Just yesterday, Hiroshima set a new three-hour rainfall record of 217.5mm. The peak was just over 100mm/hr. Massive landslides killed over 40 people. No typhoon was involved.

by kijin 12y ago

cdr 12y ago

Localized precipitation can be unbelievable when a front stalls over an area, no major event like a typhoon / hurricane even required. The September 2013 floods in the front range of Colorado caused by a stalled front topped out at 9.6mm/hour on the worst day, with 430 mm total in 6 days - just under the average annual precipitation.

kijin 12y ago
9.6mm/hr is an order of magnitude lower than what this Japanese reservoir is expected to handle. It would be considered heavy rain, but not at all unusual, for monsoon season in East Asia. It happens a few times every summer, so most cities in Japan and Korea are equipped to handle it just fine. If such events were more common in Colorado, they would have been better prepared, too.
kijin 12y ago
Well, turns out you're right that there's no need for a typhoon in order to produce 100mm/hr of rain. Just yesterday, Hiroshima set a new three-hour rainfall record of 217.5mm. The peak was just over 100mm/hr. Massive landslides killed over 40 people. No typhoon was involved.