A slowly organizing tropical low near southern Taiwan will threaten the country with flooding downpours in advance of potential impacts from Mangkhut.
While currently not classified as a tropical depression or tropical storm, an area of tropical low pressure located near southern Taiwan will provide rounds of rain to portions of the country.
This low, along with the Mei-yu front, has already produced heavy rain across northern Taiwan on Saturday when in excess of 300 mm (12 inches) of rain fell across portions of New Taipei and Taipei Cities.
The deluge continued on Sunday as additional rain fell across the area. A two-day rainfall total in Shilin District, along the northern coast of Taiwan, reached nearly 500 mm (20 inches).
— Taiwan News (@TaiwanNews886) September 8, 2018
Downpours such as this are expected to continue into the first half of the coming week, though will concentrate largely to the south of Taipei.
The heaviest rain and most likely areas to see flooding will be across eastern and southern parts of the island as as tropical low slowly passes nearby early in the week.
There remains a chance that this low will develop into a tropical storm while near southern Taiwan. If this does organize into a tropical storm, gusty wind will be felt across southern Taiwan in areas such as Taitung, Pingtung and Kaohsiung Counties.
Wind, however, is not expected to get strong enough to cause damage. Regardless of the amount of tropical development, flooding downpours will still threaten.
If this low does not organize into a tropical cyclones near Taiwan, it will become more likely to form once across the South China Sea on Tuesday or Wednesday.
After the tropical low pulls away from Taiwan, residents of not only Taiwan, but also the Philippines and southeast China will have to monitor strengthening Typhoon Mangkhut.
AccuWeather Senior Meteorologist Dave Houk expects Mangkhut to be a powerful typhoon by the time it impacts Guam early in the week. Mangkhut could be near the intensity of a Category 3 hurricane in the eastern Pacific and Atlantic Oceans.
Residents from Guam to Saipan should be completing preparations for potential impacts from Mangkhut on Monday. Wind gusts in excess of 160 km/h (100 mph) would be possible near the storm. Wind gusts to 195 km/h (120 mph) are possible should the strongest part of the storm cross an island. Rainfall up to 250 mm (10 inches) can lead to flash flooding.
Beyond that, Houk said, “A west-to-northwest path will continue the rest of the week with the potential for the cyclone to reach super typhoon status while across the Philippine Sea.”
Residents from the northern Philippines into Taiwan and southeast China should closely monitor the track of Mangkhut an begin making preparations as there is the potential for the cyclone to remain very dangerous as it barrels towards southeast Asia late in the week and into the weekend.