Japan Faced with Severe Flooding

The worst flooding that some parts of Japan have seen in decades occurred this past week as a tropical storm brought tropical, moisture-laden air to the country.

Tropical storm Etau had the worst impact on Japan’s biggest island, Honshu. Here heavy rain bands were set up for over 24 hours in the area and rainfall totals were further enhanced by local topography. Unstable terrain leading to mudslides also grew to be a concern as heavy rain fell and the ground became saturated. By the end of this past week, when the rain was all said and done, some villages in central and southern Honshu had rainfall totals near 700mm, with some 24 hour totals topping 500mm. It’s to note that the average monthly rainfall for September in Tokyo is less than a third of that (181mm). Here are a few of the notable rainfall amounts (provided by weather.com) :

  • Ikari 551*mm* in 24 hours.
  • Nikko 668*mm* rainfall total.
  • Kanuma 444*mm* in 24 hours, which is more than double the previous 24 hour record for the city (record 212*mm* in 2002).
  • Sendai central business district 269*mm* 24 hour total
Levees of the Kinugawa River breached in Joso from the heavy rains. (Source: AFP/via TWC)
Levees of the Kinugawa River breached in Joso from the heavy rains. (Source: AFP/via TWC)

What resulted from these very high rainfall amounts was historic flooding, mainly north and northeast of Tokyo. Over 13,500 buildings were reported to be completely flooded out by officials in result of the heavy rain falling as well as some levees being breached north of Tokyo. In total 3 people have been confirmed to have died from this rainfall event and 23 are still missing; mostly from landslides. It was reported that 185,000 were forced to leave their homes, while over two million more were advised that they should leave by authorities. It’s not possible to assign a dollar amount to the damages yet but authorities speculate it will at least be in the hundreds of millions.

Flooding in the city of Joso, where floodwaters nearly reached the second story of homes. (Source: CNN)
Flooding in the city of Joso, where floodwaters nearly reached the second story of homes. (Source: CNN)

A few showers are expected this weekend in the Tokyo area but nothing close to the magnitude of what seen this past week.

Elsewhere in Weather News: December 13th, 2014

West Coast Hit With Strong Winds, Heavy Rains

The West Coast of North America has been subject to several systems after coming onshore in the past couple weeks, bringing with them heavy rains and strong winds which has led to flooding. Once again, the culprit for the moisture-laden systems in this region has been the atmospheric river. This atmospheric river is a term used for streams of moisture typically originating in the tropics, which head Poleward. Eventually the water precipitates out – it is often enhanced along the west coast due to orographic precipitation, leading to flooding.

Higher PW values streaming from the tropics to the Californian coast are associated with the atmospheric river. (Source: CIMMS)
Higher PW values streaming from the tropics to the Californian coast are associated with the atmospheric river. (Source: CIMMS)

Earlier this week, the BC coast was hardest hit where over 400mm fell on parts of Vancouver Island in 6 days. Flood watches were issued as towns on the Island watched waters rise. The towns of Courtenay and Port Alberni were soaked with over 150mm by Wednesday – some residents were forced to evacuate their homes due to the rising waters. Strong winds were also a problem; gusts over 100km/h were recorded across the coast, even in large cities such as Portland, OR. These winds knocked out power to roughly 75,000 residents in BC alone. In addition to the wind and rain, landslides also became of concern in Southern California. Saturated grounds led to a large slide in Camarillo Springs, CA, which affected over a dozen houses.

Estimated rainfall along the BC coast from December 4 to the 10th. (Source: Environment Canada)
Estimated rainfall along the BC coast from December 4 to 10. (Source: Environment Canada)

The system even brought a weak EF-0 tornado which was spun-up in one of the stronger rain bands that came onshore. The tornado passed through a small area in southern Los Angeles yesterday morning and stripped roofs of their tiles – no one was injured thankfully. Reports of 60-100mm were common along the Californian coast, but localized amounts of 200mm or higher did occur. The highest precipitation report as of Friday came from an area in the northern Sierra Nevada Mountains where 450mm of precipitation fell; the amounts here were enhanced by orography.

Unfortunately models are showing another system impacting most of the West Coast early next week, not leaving much time for things to dry out.

Elsewhere in Weather News: September 29th, 2013

Wutip Forms, Typhoon Usagi Update

This week the Northwest Pacific typhoon season continues to be active as another typhoon – typhoon Wutip – has spun up in the South China Sea and is tracking westward. Although this is good news for the residents of Hong Kong and southern China who have been affected by last week’s typhoon, Vietnam will now have to closely monitor Wutip. As of Friday night Wutip was only a high-end tropical cyclone but is expected to slowly continue to strengthen over the open waters of the South China Sea. It will likely only have enough time to strengthen to a category one typhoon before it makes landfall near the city of Da Nang. Still, residents of Vietnam will have to watch for storm surge that could wreak havoc in low lying coastal areas as well as flooding; much rain will be associated with Wutip. It’s expected that Wutip will make landfall Sunday night.

Wutip

Infrared enhanced image of Wutip on Friday night. A bit of dry air to the south-east of it’s center but very cold tops (white) near it’s center as it was attempting to organize itself. (Source: CIMSS)

The storm talked about in last week’s EIWN, typhoon Usagi, has caused significant damage to coastal areas of China, in the Guangdong province. In total, 25 people have died in China due to landslides triggered by the heavy rains and storm surge. Search and rescue teams are still looking for survivors in the mud though, and cleanup efforts are now underway. Usagi made landfall 140km to the north-west of Hong Kong; there it brought with it sustained winds of 175km/h which gusted to over 200km/h. In Hong Kong over 200 flights had to be cancelled. Although once a powerful super typhoon, Usagi is no more as it moved over China’s mainland and fell apart this past week.