Japan faces stormy outlook

Another major typhoon is heading towards Japan. This comes just days after Typhoon Wipha brought torrential rain which led to deadly floods and mudslides.

The rainfall across eastern Honshu and the offshore islands was of a truly exceptional nature. Wipha was ‘only’ a Category One storm on the Saffir-Simpson scale (with five being the highest), but it brought near record-breaking rainfall.

Although Tokyo was hit with 246mm, more than a month’s worth of rainfall, in just 19 hours, it got off lightly compared with the island of Oshima. Lying just 120km to the south of the nation’s capital, the island was hit with 824mm in 23 hours. Even more incredibly, two thirds of that total, 549mm, fell in one six-hour period.

Not surprisingly, this deluge caused flash flooding and mudslides which killed at least 19 people, with around 40 still reported missing.

The island’s mayor has apologized for not evacuating the residents ahead of Wipha’s arrival, although there had been safety concerns about moving people during the night.

So there will be great interest in the forecast for the coming days across the region, especially as a super typhoon in the Western Pacific appears to be heading towards Japan.

The immediate issue is the heavy rain which a separate weather system will bring over the weekend. Honshu and the other southern islands could see around 100mm of rain which will fall onto relatively saturated ground.

The possible arrival of another typhoon next week gives considerable cause for concern but there remains some doubt as to the likely track of Typhoon Francisco.

Francisco continues to feed off the warm waters of the western Pacific which, along with the favourable winds through the atmosphere, have allowed Franciscio to become a super typhoon with sustained winds of 140kph. This Category 4 storm is expected to weaken as it passes northwards over cooler waters.

The latest computer forecast show considerable differences in the anticipated track of storm. All models take Francisco northwards; the issue is at what point does it turn to the right and begin to head northeastwards.

The more pessimistic forecasts suggest that Francisco will hit on Thursday with the possibility for rainfall totals well in excess of 100mm. At this stage, no one is predicting a repeat of Wipha, but the emergency authorities across the country will be alert to the possible effects of another major storm hitting the country.