Thunderstorm activity will increase across central and eastern parts of the state from Thursday. A large scale onshore wind pattern will become established later next week, feeding moisture into a trough over inland New South Wales, which will combine to produce thunderstorms. Thunderstorms are a risk anywhere east of a line from about Bourke to Griffith to Albury on Thursday, possibly becoming more widespread on Friday to extend further west. Any storm that develops brings the risk of damaging wind gusts, in addition to large hailstones. Some decent falls of rain are expected to accompany these storms, which look to fall over parts of the state where large deficits in rainfall have been observed over the last 12 months. At this stage, parts of the Central West Slopes & Plains, Northwest Slopes & Plains and Central Tablelands could see more than 30mm of rain by the end of Saturday, with localised falls in excess of 50mm possible. Storms then look to easy by Sunday, as a ridge of high pressure builds across the region.