This is the terrifying moment a transformer explodes as a storm hits the island of Phuket in southern Thailand.

Dashcam footage shows the vehicle turning along a curved road before a power unit exploded, sending sparks flying across the highway on July 20.

Driver Paweentida Salika said it was both windy and rainy in the region when the incident occurred, with Typhoon Wipha lashing the region.

She added: 'The power lines exploded and snapped. The wind was very strong. Nobody was hurt but there was a lot of damage.'

A piece of debris was thrown meters away from the pole, narrowly missing a motorist, before causing mini explosions and a fire on the roadside.

Phuket has been among Thailand's coastal provinces being pounded by heavy rain and stormy seas from Typhoon Wipha.

In neighbouring Vietnam, a tourist boat was capsized by the storm, leaving dozens of passengers dead. The vessel reportedly overturned after being hit by choppy waves and heavy rain off the coast of Ha Long Bay shortly after 2 pm local time.

The Thai Meteorological Department today predicted more heavy rain and high seas until July 24. It added that around half of Thailand will be battered with increased rainfall due to the typhoon, which made landfall in China's southern Guangdong province on July 20.

Wipha has been downgraded to a tropical storm after hitting mainland China.