Extreme weather is striking parts of Asia with deadly flash-flooding in Vietnam, a tropical storm prompting evacuations and disrupting travel in China and an ongoing heat wave in Japan, reports CNN.

In Vietnam, 21 people have died and more people are missing after Tropical Depression Son Tinh triggered flash floods and landslides, submerging villages in the northern provinces of Thanh Hoa and Yen Bai, state-run Vietnam News Agency (VNA) reported Sunday.

Local government groups are "searching for missing ones, arranging temporary accommodation for households who have lost their homes, and actively evacuating and relocating people from dangerous areas," VNA said.

The government is also mobilizing forces to fix infrastructure, including homes, heath care centers, hospitals and schools.

Winds from the storm had reached up to 52 kph (32 mph) at 10 a.m. Sunday local time (11 p.m. Saturday ET). It is expected to continue to affect Vietnam until Tuesday, according to the Vietnam National Center for Hydro-Meteorological Forecasting.

CNN meteorologist Derek Van Dam said forecast rainfall estimates could approach 500 mm (nearly 20 inches) across northern Vietnam and southern China over the next few days.

Meantime, Tropical Storm Ampil is bearing down on eastern China -- impacting the area from Shanghai to Jiangsu Province. More than 190,000 people have been evacuated to "safer" places in Shanghai as Ampil makes landfall, bringing with it heavy rain and strong winds, Chinese state media Xinhua reported on Sunday.

"Ampil, the 10th typhoon this year, has made landfall on the island of Chongming in Shanghai at 12:30 p.m. local time Sunday (12:30 a.m. ET), packing winds of up to 28 meters per second near its eye," the municipal meteorological observatory told Xinhua. The local government municipal flood control confirmed that it has "completed relocating a total of 192,727 people living in the coastal areas as well as temporary housing and construction sites as of early Sunday morning."

Winds gusting up to 100 kph and heavy rain from Ampil are disrupting travel, with more than 500 international and domestic flights canceled at Shanghai's two main airports Sunday morning.

"Tropical Storm Ampil is fast-approaching Shanghai, affecting our airports' flight schedules. Several airlines have made the difficult decision of canceling certain flights leaving and arriving at Shanghai Pudong Airport and Hongqiao Airport between 0:00 and 20:00 on July 22," the Shanghai Airport Authority said.

CNN's Van Dam says air traffic control expects their takeoff and landing capacity to be reduced by 75% through mid afternoon Sunday, and all the city's ferry services have been suspended due to strong wind.

Rainfall amounts of 100-200 mm (4-8 inches) are forecast; with localized falls of up to 300 mm (12 inches).

Van Dam says the storm will weaken as it moves further inland but that heavy rain will continue as moisture is drawn into the region.