Those in New South Wales hoping for a long weekend spent outdoors will have their spirits dampened by forecasts of heavy rain, thunderstorms and flash flooding across the state.

Sydneysiders’ three-day break will be met with muggy skies, while those with weekend getaway plans up north will be washed away with the Bureau of Meteorology issuing a severe weather warning for the area.

Some have taken to social media to vent their frustration over the stormy skies, having hoped for good weather for the remaining days of the city’s light and music festival, Vivid Sydney.

Meteorologists report a low-pressure trough off the New South Wales north coast is already causing heavy rainfall in the Northern Rivers region and parts of the mid-north coast.

https://www.instagram.com/p/BVI1neyjQpm/

In the first 10 days of June, Sydney has almost hit its average rainfall for the month. The June average for Sydney is 133 millimetres and the capital city has already received 120 millimetres.

More than 200 millimetres of rain is expected across areas including Lismore, Grafton, Coffs Harbour, Port Macquarie, Sawtell and Dorrigo in the coming days.

“It’s going to be a wet weekend,” BOM duty forecaster Anita Titmarsh told the New Daily.

Ms Titmarsh, however, quashed fears the weekend weather would be comparable to March’s Cyclone Debbie, saying the storm was nothing out of the ordinary for this time of year.

“It will be nothing of that scale,” she told the New Daily.

Ms Titmarsh called the event a “regular thunderstorm”, but said there was potential for some heavy rainfall.

“Sometimes weather modelling is very uncertain seven days out, but as it gets closer the modelling calms down,” she said.

“There could be some localised heavy falls, that’s the nature of thunderstorms – you can have a heavy fall in one location and a few kilometres away you could see very little.”

https://www.instagram.com/p/BVIkwN-AMKx/

Ms Titmarsh said showers and thunderstorms were forming over warmer ocean waters to the east and would push over the coast with the wind.

Between 9am and 3pm on Saturday, Coffs Harbour Airport received 61 millimetres of rain, Parramatta received 60mm and Kings Langley received 50mm.

“Our hydrologists are standing by to watch floods in those catchments,” Ms Titmarsh said.

The State Emergency Service advised people throughout the state not to drive, ride or walk through floodwater and keep clear of creeks and storm drains.

Moderate rain is forecast for Brisbane, the Gold Coast, the Sunshine Coast and Newcastle, while Melbourne, Perth and Hobart can expect a drier weekend.