Taiwan has been hit by a third typhoon in two weeks, a powerful storm that killed at least four people and injured hundreds of others.
This time the eye of the typhoon passed directly over the middle of the island, from east to west, starting its journey at Hualien City.
Electricity was cut for millions of residents as blown-down trees severed power lines. An estimated 72,000 households were left without running water.
The previous two typhoons kept their eyes offshore but both delivered significant rain and damaging winds. Typhoon Megi made a direct hit, and came ashore as the equivalent of a Category 2 hurricane, on the Saffir-Simpson Scale. It too delivered heavy rain and damaging winds.
The weather observers in Hualien City reported a maximum gust of 155km an hour. This is strong enough to overturn lorries, and this has indeed happened.
Reports from Taiwan’s Central Weather Bureau showed steady winds of 100km/h in Taichung City with gusts of 198km/h on Tuesday afternoon. Taichung is on the west coast of Taiwan and this suggests that Megi dropped from a Category 3 typhoon to a tropical storm as a result of the Taiwanese geography.
Megi gathered the seas to produce 11-metre high waves east of Taiwan.
— James Reynolds (@EarthUncutTV) September 27, 2016
Bands of rain revolving around the typhoon covered the entire country. In six hours of Tuesday morning, Taipei recorded 75mm. The potential from Typhoon Megi is 400mm on level ground but much more in the hills.
On Taiping mountain, since the rain from this typhoon started nearly two days ago, 984mm has fallen with 870mm on Tuesday alone. This amount of rain on a mountainside is likely to have caused landslides.
Taiwan has a mountain range running down its spine and this has two effects. Firstly it enhances the rain and secondly it disrupts the circulation of a typhoon.
This is relatively good news for western Taiwan and the coast of mainland China where Megi is headed next. A fully fledged typhoon is not going to make it across the mountains. The regenerating effects of the warm waters of the Taiwan Strait are not quite enough to rebuild a major typhoon.
The forecast track now takes Megi to the coast of China, near Quanzhou, in Fujian province. Winds will likely be around 90km/h and the rain will be heavy. The waves are unlikely to be as high as those that hit eastern Taiwan.
We have learned from recent research the storm surge that is normally the most devastating part of a typhoon is not a major factor here. The water to the east of Taiwan is too deep and the time spent over the Taiwan Strait is too short to gather up huge seas.