Weather tracker: Hurricane Lowell pounds Hawaii’s western islands

Widespread damage across Ni‘ihau, Kauaʻi and O‘ahu, while in Japan further heavy rainfall causes widespread flooding

Hurricane Lowell caused significant damage to Hawaii’s western islands this week. On Tuesday night the centre of Lowell tracked 50 miles (80km) from the island of Ni‘ihau in Kauai county as a category 2 storm with winds of up to 110mph. The strong winds resulted in widespread power outages across Ni’ihau, and the islands of Kauaʻi and O‘ahu.

The event was particularly notable because a tornado watch had been issued for Kauaʻi on Monday night and into Tuesday morning. According to research maps from Iowa State University, it was likely to be the first tornado watch in Hawaii’s history. In the event, a tornado was not documented, however hurricanes can produce tornadoes and most often occur in thunderstorms within rain bands away from the centre of the hurricane. Currently, five named stormed have occurred in the central Pacific with the strong El Niño this year being a key driver in the above normal hurricane season, as noted by the National Weather Service.

In Asia, further heavy rainfall in Japan has caused flooding of roads and subway stations, disrupting services including the main bullet train Tokaido Shinkansen. A record-breaking 104.5mm of rain fell within an hour through Tuesday afternoon in Nagoya. The heavy downfall occurred because of a stationary front and moist air mass associated with tropical depression Krovanh, resulting in extremely unstable conditions. A level-two advisory remained in place for landslides on Friday across the country. Some landslides have already occurred, including one of the main starting points for Mount Fuji on Wednesday, covering three vehicles in debris. No injuries or fatalities were reported.

Heavy rainfall also hit large parts central-southern Europe in recent days. Earlier this week, cooler air pushed south-east across much of the continent, displacing the warm air mass behind southern Europe’s late season heatwave. The boundary between the two air masses, a cold front, reached the Mediterranean by Wednesday. There, the front helped create ideal conditions for violent thunderstorms: cool air moving over the Mediterranean’s unusually warm waters created an unstable atmosphere, while the sea supplied plenty of moisture. As a result, large thunderstorms formed over the waters around Corsica, Sardinia and northern Italy on Wednesday and Thursday, producing torrential rainfall and flash flooding, strong winds, as well as a few tornados.

At a weather station in Veneto, 154.2mm of rain was recorded in just 3.5 hours. The storms pushed north-east into Austria and the Balkans late on Thursday with a few forecast to continue into Friday. However, this wet weather is not expected to persist in the region over the weekend and into the start of next week, with drier and sunnier weather likely to develop.