SEVERE thunderstorms are likely to produce large hailstones and damaging winds in Orange on Monday afternoon

The Bureau of Meteorology has warned that the storm may hit Taree, Scone, Penrith, Bowral, Mudgee and Katoomba. 

The warning was issued on Monday morning, with further updates expected on Monday afternoon.

Severe thunderstorms are likely to produce large hailstones, heavy rainfall that may lead to flash flooding and damaging winds in the warning area.

Other locations which may be affected include Mudgee, Bathurst, Cowra, Parkes and Wellington. 

The State Emergency Service advises that people should: 

- Move your car under cover or away from trees. 

- Secure or put away loose items around your house, yard and balcony. 

- Keep clear of fallen power lines. 

- Keep clear of creeks and storm drains. 

- Don't walk, ride your bike or drive through flood water. 

- If you are trapped by flash flooding, seek refuge in the highest available place and ring 000 if you need rescue. 

- Unplug computers and appliances. 

- Avoid using the phone during the storm. 

- Stay indoors away from windows, and keep children and pets indoors as well. 

- For emergency help in floods and storms, ring the SES (NSW and ACT) on 132 500.