UPDATED

The Bureau of Meteorology has cancelled a severe thunderstorm warning for Sydney

Warning: A severe thunderstorm warning was issued earlier today but was later cancelled. Picture: John Veage
Warning: A severe thunderstorm warning was issued earlier today but was later cancelled. Picture: John Veage

Update

A severe thunderstorm warning in place for Sydney this morning has been cancelled.

The Bureau of Meteorology had issued the warning at 8.27am today and said thunderstorms could bring large, possibly giant hailstones, heavy rainfall and damaging winds.

St George and Sutherland Shire received some rainfall, with Woronora Dam recording 3 millimetres of rain this morning.

It will be partly cloudy for the rest of the day, with a chance of showers and a possible thunderstorm later today.

Sydney is expecting a top temperature of 28 degrees.

A poor air quality alert has been issued due to smoke and dust haze.

Update

St George and Sutherland Shire residents should prepare for the worst, with a severe thunderstorm warning in place this morning for Sydney.

The Bureau of Meteorology issued the warning at 8.27am today and said thunderstorms could bring large, possibly giant hailstones, heavy rainfall and damaging winds.

Sydney sweltered through a warm night after sweating through temperatures of more than 40 degrees yesterday and woke to humid, smokey conditions and "hazardous" air quality.

The State Emegency Service (SES) Sutherland Shire has urged motorists not to drive through flood waters.

Update

The NSW Government has asked the public to cut down on unnecessary electricity usage this afternoon as energy demand skyrockets due to the weather conditions.

Electricity supply is expected to be near full capacity this afternoon, prompting Energy Minister Matt Kean to appeal to consumers and businesses to reduce demand on the electricity grid for the next few hours.

"The tight conditions in the electricity system this afternoon are largely a result of the state's weather conditions, bushfire impacts on transmission lines and mechanical issues at some of the state's power stations," he said.

"The peak period for power use in NSW is expected to be between 4pm and 8pm, according to the Australian Energy Market Operator (AEMO), and we are asking consumers to reduce their demand during this period where it is possible and safe to do so.

"During a similar heatwave incident earlier this year, a fantastic consumer response went a long way to reducing the load on the grid.

"We are again asking everyone in the community to play their part in reducing pressure on the national grid."

He suggests taking the following steps:

  • closing doors, windows and blinds to keep the heat out;
  • switching off non-essential appliances such as pool pumps;
  • cooling a minimum number of rooms;
  • setting air conditioners to 26 degrees.

According to the Bureau of Meterology's latest Sydney weather observation, the temperature at Sydney Airport at 4.32pm is 41.5 degrees, while at Lucas Heights it is 39.6 degrees.

A cool change is not expected until at least 2am tomorrow.

For energy saving tips click here.

Mercury rising: Crowds flock to Cronulla's beaches for the second day in a row as temperatures reached 41 degrees in parts of St George and Sutherland Shire yesterday. Picture: John Veage

Mercury rising: Crowds flock to Cronulla's beaches for the second day in a row as temperatures reached 41 degrees in parts of St George and Sutherland Shire yesterday. Picture: John Veage

Earlier

St George and Sutherland Shire will swelter today, with Sydney set to reach temperatures of 41 degrees.

The Bureau of Meteorology has predicted hot, windy conditions for the rest of today, with a possible late thunderstorm.

A poor air quality alert has been issued due to elevated particle levels and a dust haze that is likely to descend this afternoon.

NSW Rural Fire Service crews are on standby across Sydney and a total fire ban is in place due to the severe fire danger.

Sutherland Shire Rural Fire Service (RFS) Inspector Scott Deller warned conditions were very dangerous today.

"We are on track for a very ordinary day in terms of fire weather and this is supported by the observations recorded by the Bureau of Meteorology weather balloon launch, which was released from Sydney Airport earlier this morning," he said.

"The temperature across the Sutherland Shire will reach the low 40's, with very dry air mixing down and north-westerly winds averaging up to 40kmh, with gusts around 75kmh possible."

Inspector Deller said that while the recent rain played an important role in mitigating bushfire danger, any advantage would be "rapidly eroded throughout the day".

A weak and shallow southerly change is set to move up the coast throughout the day but is not predicted to reach the shire until the very early hours of Friday morning.