Auckland motorists have been forced to deal with near zero visibility and surface flooding as torrential downpours hit the city. Minor to moderate surface flooding has been observed on some motorways and on side roads around the central city, according to WeatherWatch.co.nz. Motorists have been slowing down to the conditions, with some motorways travelling at just 60km/h despite few vehicles. WeatherWatch.co.nz said a particularly heavy band of rain moved across the city early this afternoon, and while the worst has passed, more pockets of torrential rain are already moving back in. Humidity remains in the 90 per cent range. Torrential rain and thunderstorms are now also hitting Northland. WeatherWatch.co.nz said the lightning tracker has sparked up this afternoon around the top of the country as the main front slowly moves through. WeatherWatch.co.nz said the risk for surface and flash flooding across Northland, Auckland, Waikato, Coromandel Peninsula and Bay of Plenty remains high this afternoon. To a lesser extent coastal Otago and Dunedin are also at a high risk for surface flooding, but not flash flooding, as rain continues to fall there. Conditions are expected to ease in Auckland, Waikato and Northland later this afternoon then ease elsewhere overnight.