Meteorologists are picking the potential for a blast of snow across parts of New Zealand next week – while a rare phenomenon now unfolding over Antarctica could spell more “active weather” later in August. A low-pressure system moving in from the Tasman Sea is forecast to collide with cold air blowing up from the Southern Ocean - bringing the possibility of snow on Monday and Tuesday. The risk for heaviest snow looked to be in the southern Canterbury High Country and northern parts of inland Otago, at elevations of 800m and possibly lower levels.