Sydney is hit by hail and thunderstorms hit the country

Sydney was rocked by hailstorms and thunder, causing flight cancellations, flash flooding and affecting light rail services.

Thunderstorms struck Sydney this afternoon, with lightning strikes and massive hailstorms hitting homes in the city's west, while forecasters warn the rest of the country will be hit by more storms later this week.

An outbreak of potentially severe thunderstorms is expected to hit eastern Australia from this afternoon into Wednesday, according to the Bureau of Meteorology.

Almost 4,000 people were affected by power outages from 3.30pm, with Ausgrid outages reported in Hurstville and North Manly.

Some flights to and from Sydney were delayed or canceled.

“There have been some flight delays and cancellations due to storm activity,” a Sydney Airport spokesman said.

“We encourage passengers to check with their airline about the status of their flight.”

The Bureau of Meteorology said a severe thunderstorm had caused heavy rainfall that could lead to flash flooding across Sydney, from Olympic Park in Homebush to Bondi Beach.

They said the thunderstorm was moving north-east and was likely to hit Manly and St Leonards before moving over Dee Why later in the afternoon.

Images shared with 9news.com.au showed massive hailstones falling on the Emu Plains and near the Blue Mountains.

Hail was also reported on Sydney's northern beaches and inner west.

Sydney's light rail system was also affected by flooding on the tracks, with the L2 Randwick and L3 Kingsford lines closed between Moore Park, Randwick and Juniors Kingsford.

Thunderstorms are expected every day in some parts of the country this week thanks to a series of low-pressure areas and depressions.

Storms were already brewing across southern and eastern Australia this morning, meteorological service Weatherzone said.

A low pressure area is expected to drift eastwards from WA, bringing storms across the rest of the country on Thursday and Friday.

They could bring damaging winds, large hail and downpours.

It will rain for several days in both Sydney and Melbourne.

A mass of hot air concentrated over central Australia is causing some of the turbulent weather.

Weatherzone says daytime temperatures in northern South Australia could reach the mid-40s on Wednesday and Thursday.

Nighttime minimum temperatures will also be higher than usual and could challenge this season's heat records.