According to Weatherzone, Bathurst could receive 5-10mm on Friday, 1-5mm on Saturday and Sunday, 10-20mm on Monday and 1-5mm on Tuesday.

Weatherzone meteorologist Brett Dutschke said there will be two main periods of rain between Friday and Tuesday.

"It's [rain] virtually guaranteed and it looks like between Friday night and mid-next week, there's going to be two main periods of rain," he said.

"Rain could start as early as Friday morning, but it looks like the heaviest rain in this first spell will be Friday night, early Saturday morning. In this first lot, you're looking at five to 10 millimetres, potential for a bit more.

"Then it's going to be dry for the whole time between Saturday evening to Sunday afternoon. We should see some rain start developing again and it looks like on and off from Sunday afternoon to Tuesday afternoon."

Mr Dutschke said it'll get increasingly windy from Sunday afternoon to Tuesday afternoon too.

He said the two main periods of rain are being driven by two different systems and coming from different directions, with a break down in between.

"The more intense weather is going to be in the east," Mr Dutschke said of the rain period from Sunday to Tuesday. "This second period of rain is likely due to a low pressure system forming off the coast.

"Whereas on Friday to early Saturday, it's a system coming across from the west and that'll be drawing moisture from the tropics.

"It looks like the wetter places will be in the west. Two different systems, with a bit of a break in between."

The rain on the way could be a welcome boost for Ben Chifley Dam too, which sits at 39.2 per cent capacity as of July 7.

For up to date weather forecast and details, visit the Weatherzone website at www.weatherzone.com.au.