Powerful storm hits Hokkaido, Japan

Tropical Storm "Choi-wan" interacted with a mid-latitude trough and generated a strong extra-tropical low system on October 7, 2015. The system is currently packing extremely strong winds of typhoon strength that already began affecting parts of Hokkaido island, Japan. Red warning for storm surges, coastal flooding and heavy rainfall was issued for the largest part of the island, as of October 8, Japanese Meteorological Agency (JMA) reports.

Choi-wan formed as a tropical depression on October 2 then intensified into a tropical storm by October 5. The system continued to strengthen and developed into a typhoon on October 6, then started to weaken down and merge with a mid-latitude trough, according to Joint Typhoon Warning Center (JTWC). This interaction has generated a very intense extra-tropical low pressure system with an extensive area of associated low-level winds exceeding gale force, as of October 7.

Video credit: WestPacWx

The system is expected to approach Kuril islands on October 8 with maximum sustained winds of about 80 km/h (50 mph). 

Severe winds of typhoon strength have been reported in parts of Hokkaido on October 8. A funnel cloud was reported to from over waters off the coast of Okinawa.

Extra-tropical low pressure system over parts of Japan, synoptic situation, October 8, 2015. Image credit: NASA Aqua/MODIS

The extra-tropical low is expected to pass over the northeast area of the island on the evening of October 8 packing winds up to 162 km/h (100.7 mph) with a central pressure estimated to reach below 950 hPa, WestPacWx reports.

The worst hit area will be most likely be Nemuro, as high tide and strong winds could trigger a coastal flood across the area. Mountain regions expect between 10 and 20 cm (3.9  to 7.9 inches) of snow, as of October 8.

Extra-tropical low wind strength, October 8. See animation at: earthschool. net

During early UTC morning of October 8, JMA issued a red warning for storm and high waves for the northern and central-western Honshu and Hokkaido islands. A red warning was also issued for heavy rain, storm surge and floods for northern and eastern Hokkaido island.

A red warning was put in effect for severe winds and heavy rainfall in Sakhalin Oblast in Russia, as of October 8, the Hydrometeorological Centre of Russia reports.

Featured image: Extra-tropical low pressure system slamming into Japan, October 8. Image credit: NASA Aqua/MODIS