Worst of the wild weather to hit NSW coast

Commuters in Sydney and on the NSW coast can expect a wet trip to work as heavy rain and severe thunderstorms reach their peak.

Parts of NSW have been warned to brace for more rain and severe thunderstorms as a deep coastal trough makes its way through the state's coastal fringe.

After a wet commute to work on Monday, Sydneysiders and residents on the south coast can expect a wetter journey on Tuesday.

Two severe weather warnings were issued by the Bureau of Meteorology with heavy rainfall and abnormally high tides forecast for the south coast and heavy rain with thunderstorms expected in the central tablelands region.

The worst affected region will be the south coast with a deep coastal trough drenching the area and putting it on flood watch from Monday night into Tuesday evening.

Water levels on the south coast could reach or exceed the highest tide of the year especially during Tuesday morning.

Rainfalls of 20mm in 20 minutes are likely along the coast and even in Sydney, bureau senior forecaster Mohammed Nabi says.

An east coast low is forecast to develop across the state's coastal fringe on Tuesday afternoon, but the worst of the weather will be caused by the trough in the lead up to the east coast low.

The wild weather should clear up by Wednesday, with a few showers forecast, but nothing compared to Monday and Tuesday's wet weather.