There are growing signs that heavy rain and potentially damaging winds will impact parts of eastern NSW later this week.

An upper-level cut-off low pressure system is expected to drift over NSW from today and linger over eastern Australia for several days.

Weather meteorologists Ben Domensino says there is some uncertainty regarding the strength and position of the low-pressure system later this week, which makes it difficult to accurately predict its impacts.

Those travelling this weekend are advised weather modelling suggests that the heaviest rain and strongest winds will probably occur along the Mid North Coast and possibly in parts of the Hunter or Northern Rivers districts with forecasts of localised rainfall totals of more than 200 mm from this system which would be enough rain to cause flash flooding.