Thunderstorms in northern New South Wales have been working overtime, sparking up yesterday evening and continuing into today. A low pressure trough began moving its way across the state yesterday, filtering warm and gusty northerly winds ahead of it. This brought some of the warmest temperatures since April for some parts of central and northern NSW, while Kempsey, 29.4 degrees, and Norah Head, 27.9, had their warmest day since March. Storms sparked up in the early evening around Coonabarabran, before slowly spreading to the east. Over 6000 lightning strikes occurred over the North West Slopes and Plains, Northern Tablelands and Mid North Coast. Rather than Princely purple rain, radar echoes from these storms were generally a green shading indicating only mild rainfall totals, with just one to two millimetres. Thunderstorms often run out of puff overnight, but a number of factors combined to keep them going last night. Non-stop thunderstorms overnight occurred due to uplifting over the slopes and ranges, a cooling upper atmosphere and a slow easterly trajectory towards a more moist atmosphere. Storms will keep rolling on today before intensifying later this afternoon. The North West Slopes and Plains, Northern Rivers, Northern Tablelands and Mid North Coast will see the worst of these storms. They could become severe with large hail, most likely over northern parts of the Mid North Coast. Storms will spark up again tomorrow afternoon over eastern parts of the Mid North Coast and Northern Rivers before a ridge of high pressure brings more stable conditions on Friday.