Debris was sent flying into backyards and roofs ripped off properties as the wild weather caught residents by surprise.

A water spout turned into a tornado as it hit land about 5.30pm yesterday, wreaking havoc across City Beach. 

Multimillion-dollar homes, roofs, trees and fences were in the firing line.

A garage on Lantara Crescent was torn apart in less than a minute.

Perth artist John Major heard screams from inside his home after a giant piece of his neighbour’s porch from 200 metres away smashed an outdoor glass table.

“I’ve never experienced anything like this, it was almost like if you’d stood behind a jet engine, it came as quickly and disappeared as quickly as it came,” he said.

His sick wife was on the couch just centimetres behind the window.

“She would have been dead, my wife would have been dead, there’s no doubt about it,” he said.

Around the corner on Kalari Drive, a family of four made their own lucky escape when the severe cell stripped their roof.

They were forced to book an unexpected hotel stay when their home was deemed too unsafe to sleep in.

Closer to the coast, 60-year-old Norfolk pines were stripped bare, some even sliced in half by more than 100km/h winds. 

“It was very scary, we thought the windows were going to blow in at one point,” Zarin Milambo said.

“You don’t expect tornadoes in Perth.”

Residents banded together 7am to start the clean up, which is likely to take days.

“I was faced with devastation in my front yard, all the verge trees had been struck by what looks like a cyclone or mini tornado,” Anita McSweeney said.

“I couldn’t believe it, my mind just went to images of Cyclone Tracy.”

The tornado caught residents by surprise, some describing the sound like “missiles” hitting their homes.

SES crews responded to 35 requests just in City Beach, where more than a dozen homes were affected but it wasn’t the only suburb hit.

As the supercell moved from City Beach to South Perth it caused damage to Perth hospitals, forcing surgeries to be cancelled today.

Hollywood Private Hospital was forced to cancel cardiac procedures due to flooding and patients from Sir Charles Gairdner Hospital’s intensive care unit were moved out after torrential rain damaged the building

The Swan River swallowed parts of the foreshore as a downpour soaked much of the state, dumping 75 millimetres in Kings Park, 71 millimetres in South Perth and almost as much in several other suburbs.

Hail, lightning and thunder was also seen and heard across the city.

WA sees about three to five tornadoes every cold season but they’re rare in Perth.

This one first appeared as a water spout about 5.30pm off City Beach before hitting land and becoming a tornado.

They form from rotating air along the boundary of a cold front or thunderstorm.

As the air starts to rise through the atmosphere, it stretches and spins faster and faster, resulting in a tornado.

It can form in two different scenarios, super-cell or non-super-cell tornado. Forecasters say it’s likely this one was a variation of a super cell.

“We only saw it popping up on the radar right as it formed right off the coastline and that provides us very little scope to provide warnings,” Bureau of Meteorology meteorologist Jessica Lingard said.