Thunderstorms rumbled across the New South Wales ranges during Sunday, bringing blustery winds and the heaviest rain for months to some areas. By lunch time on Sunday thunderstorms had flared up along the NSW ranges, becoming more intense and widespread as the day progressed. The storms maintained momentum during the evening, reaching the far northeast of the state on Monday morning. The system responsible for the storms was a low pressure trough, which was fed by moist onshore winds leading to some localised heavy falls. The North Coast had the highest totals to 9am on Monday. Cape Byron picked up 51mm, 19mm of which fell in just ten minutes on Monday morning. This is the most they've had since June. Ballina also copped a soaking with 33mm, 17mm of which fell in half an hour, making for difficult driving conditions. The Northern Tablelands also had some heavy falls. It was Armidale's heaviest December rain for two years with 18mm, while Glen Innes had 24mm in the gauge. Lightning Ridge in the Upper Western has now had 141% of their normal December rainfall, after 29mm during the past 24 hours raised the monthly total to 89mm.. Very strong winds accompanied some of the storms, with winds gusting over 80km/h at Moree and over 70km/h at Tamworth. On Monday morning thunderstorms contracted into the Upper Western and across the border into southern QLD. Storms are expected to fire up again over the Northern Tablelands, Northwest Slopes and Plains and the Northern Rivers this afternoon. These storms again bring a risk of flash flooding, damaging winds and large hail.