Severe storm warnings cancelled for NSW east coast

Severe storm warnings have been cancelled for the New South Wales east coast after a day of heavy rain and flash flooding.

It comes after Sydney was hit by a violent storm cell over the past two days, which brought flash flooding, lightning strikes and hail to the western suburbs.

The Bureau of Meteorology (BoM) said this afternoon severe thunderstorms are no longer occurring in the Mid North Coast, Hunter, Metropolitan, Illawarra, Central Tablelands and Lower Western districts

READ MORE: House destroyed after suspected lightning strike

Slow moving thunderstorms have been forecast for upper western parts of the state.

"A surface and upper trough are combining with a humid airmass to produce slow moving thunderstorms across inland parts of the state," the BoM said.

"A coastal trough along the Sydney and Illawarra coast is also supporting enhanced thunderstorm activity.

"Severe thunderstorms are likely to produce damaging winds and heavy rainfall that may lead to flash flooding in the warning area over the next several hours.

"Locations which may be affected include Moree, Narrabri, Walgett, Tibooburra, Bourke and Lightning Ridge."

Sydney lashed by violent storm

Sydney's western suburbs were the hardest hit when a furious storm cell bore down yesterday afternoon.

A home was set alight in the western suburbs of Glenmore Park yesterday after it was struck by a bolt of electricity.

No one was injured, but the house was all but destroyed.

The cell brought large hail to St Mary's, Box Hill experienced flash flooding, and trees were uprooted in Emu Plains.

In just half an hour, Penrith was smashed by wind gusts of 90km/h, flash flooding, torrential rain, hail and lightning.

Drivers were filmed navigating floodwaters in Penrith, with some forced to push vehicles to safety.

Overnight emergency crews have been cleaning up that damage.

This morning at least 3000 homes were without power.

Storms to be felt across three states

The BoM yesterday warned showers and storms would increase throughout the week.

The wild weather is the result of a surface trough, and will impact Queensland, NSW and Victoria.

"A surface trough lying across eastern inland Australia will trigger showers and thunderstorms through the week," BoM wrote.

"The activity (will be) initially focused across southern and central Queensland, eastern and northern NSW and eastern Victoria."

Perth to swelter through extreme heat

Meanwhile in Perth, extreme heat will continue as the city is expected to topple heat records.

"The city is about to break its record for the most number of days at, or above, 35C in a single summer," Weatherzone wrote.

"Sunday, February 20th, was Perth's 31st day at or above 35C so far this summer. This is the equal highest number of 35C days on record for a single summer, matching the same feat in 1977/78.

"There have also been 13 days at or above 40C this season, smashing the previous summer record of seven 40C days in the summer of 2015/16."