Severe thunderstorm warning for large hail and damaging winds for much of NSW, ACT

Severe thunderstorms are likely to bring large hailstones and damaging winds to much of NSW and the ACT this afternoon.

There is a weather warning that takes in much of the state, from Wilcannia in the west all the way down to Cooma in the south-east.

Locations which may be affected include Orange, Canberra, Goulburn, Wagga Wagga, Hay and Cobar.

The Bureau of Meteorology's (BOM) warning takes in: "Southern Tablelands, South West Slopes, Riverina, Snowy Mountains, Australian Capital Territory".

As well as "parts of Illawarra, South Coast, Central Tablelands, Central West Slopes and Plains, Lower Western and Upper Western Forecast Districts".

It was updated to include the Sydney and Wollongong areas.

There is also rain forecast for much of the east coast including Sydney, Wollongong, and down to Bega and Eden near the Victorian border.

"We've already seen some thunderstorm activity, in parts of NSW, specifically around ACT and Canberra region," the BOM's Agata Imielska said.

There is a cool southerly change moving through the state which is bringing strong winds that could move storms north-east.

Further north, there is a fire warning for the far north coast as the hot and windy conditions continue there before the cool change moves in.

The Pacific Highway at Glenugie, near Grafton has been closed due to a bushfire in the national park.