In the Atlantic basin, the tropical storm season is currently calm and unspectacular, and this will not change much over the next few days. The situation is quite different in the Pacific, where three systems are making the headlines, some of them very negative.
Hurricane Dora and the fire disaster on Maui
Hurricane Dora has already had a long journey. In late July, a low formed over Central America(Honduras and El Salvador), which then moved westward out to the Pacific Ocean. On August 1, Dora became a tropical storm just west of Mexico, and finally a hurricane on August 2. The day before yesterday and yesterday, it passed south of the Hawaiian archipelago as a Category 4 hurricane, doing so at a distance of about 800 kilometers. Despite this distance, Dora had far-reaching consequences on Hawaii – and here especially for Maui! The wind freshened up and reached peaks of 80 to 100 km/h, thus heating up the forest and grass fires prevailing there. The cause of the fires has not yet been completely clarified, but it could have been caused by arson or by power lines and transformers damaged by the wind.
Fig. 1: Satellite image of Hurricane Dora southwest of Hawaii; Source: tropicaltidbits.com
Hawaii has a tropical climate, but there are differences between the various islands and especially on the islands themselves – namely between the respective east and west side. The east sides are usually densely covered with large amounts of rain, while on the west side, which is away from the wind, it is often dry. This is particularly pronounced on Big Island, but this pattern is also evident on Maui. The fires were and are found on the west side, the strong to stormy winds driving the fire from the land towards the coast. The old whaling town of Lāhainā with a population of just over 12,000 was a real gem and not only popular with tourists, according to recent pictures it fell victim to the flames almost completely! Up to now one assumes 36 death victims, this number could rise however still. Numerous people suffered burns and fled from the fire into the sea. Also further south in Kihai it burns topically.
The number of forest fires in Hawaii has quadrupled in recent decades. Experts believe the cause is unmanaged grasslands with introduced, non-native grass species. This grass is currently very dry, and a fire warning was already in effect for this section of the coast recently.
Normally, storms over open ocean are rarely worth a real headline, but aside from the impact on Hawaii, Dora is special in other ways. Meanwhile, the track is already nearly 6000 km long, and there is no question of an end! Hurricane Dora is expected to cross the International Date Line tomorrow, moving from the East to the West Pacific. With it it becomes however also by definition of the hurricane to the typhoon. This, of course, is purely a matter of designation, as it does not change the tropical storm system itself. After Hurricane John in 1994 and Hurricane Genevieve in 2014, Dora is only the third storm in this category to do so since observations began. Incidentally, there was already a Hurricane Dora in 1999, which moved from the eastern and western Pacific, covering about 10,500 km (the second longest track of a tropical storm in the Pacific after Hurricane John in 1994). However, the system crossed the International Date Line only as a tropical storm and no longer as a hurricane.
Tropical Storm Khanun hits South Korea
Khanun has since reached densely populated South Korea. The tropical storm was slow to move and had previously brought enormous amounts of rain to southern Japan. In Hongawa on Shikoku Island, 333 mm of rain fell within 6 hours, and 558 mm in 48 hours. In Hinokage on Kyūshū it was 214 mm in 6 hours, in 48 hours 619 mm! Also in South Korea several 100 mm are now expected, floods and landslides are the result.
Fig. 2: Satellite image of tropical storm Khanun over South Korea; Source: tropicaltidbits.com
Typhoon Lan heads for Japan
The third currently active storm system is Typhoon Lan. It is currently gusting between 150 and 170 km/h and will continue to strengthen over the next few days. Between 14 and 15 August, it will hit Japan, and the metropolis of Tokyo will probably also be affected. We will report on further developments here.
Fig. 3: Calculated track of Typhoon Lan; Source: Joint Typhoon Warning Center