Severe thunderstorm warnings have been issued in NSW each day this week, with more dangerous storms likely to develop in central and northern parts of the state on Thursday.

A slow-moving low pressure trough crossing NSW this week has combined with warm, moisture-laden air and an unstable atmosphere to produce daily showers and storms.

Severe thunderstorm warnings were issued in parts of NSW during the last three days.

On Monday evening, Tibooburra collected 14mm of rain in two hours, which was its heaviest fall so far this year. Tuesday's storms produced a wind gust of 85km/h at Forbes and 26mm of rain in Bourke. This was also Bourke's heaviest rain so far this year and equal to its long-term monthly average for October.

On Wednesday, storms spread across the eastern half of NSW and interacted with moisture flowing off the unusually warm Tasman Sea. This resulted in a particularly intense and slow-moving group of storms passing over western Sydney in the evening.

Penrith was inundated by 71mm of rain in just one hour on Wednesday evening, which is more than their entire October average of 54mm. Penrith's total of 75mm from the night's storms also made it their wettest spring day in 22 years of records.

The low pressure trough will cause more showers and thunderstorms across a large area of northern and central NSW on Thursday, mainly during the afternoon and early evening. These storms may affect parts of Sydney and are likely over the state's central ranges and northwest slopes and plains.

Storms will become more confined to the state's northeast on Friday as the trough weakens and moves further east.

Visit http://www.weatherzone.com.au/radar/ to see where storms are moving on the radar.