Election day weather turns sour with lightning, heavy rain and thunderstorms

Most of the North Island and the upper South Island is under a severe thunderstorm watch as voters head to the polls on election day.Overnight Friday, MetService recorded nearly 2000 lightning strikes throughout the top of the North Island, as well as heavy rainfall, with downpours reaching 33.5mm an hour in the Bay of Plenty.About 1845 lightning strikes were recorded from midnight.The MetService weather map for Election Day shows weather warnings in the North Island and upper South Island.MetService / ScreenshotFire and Emergency responded to five weather-related callouts overnight, including flooding and reports of fallen trees.In Auckland's Grey Lynn between Elgin and Northland streets, a billboard came down in strong winds. It knocked over fencing and is lying across the footpath and cycle lane and onto the road.MetService is warning of a moderate risk that thunderstorms may become severe across a broad swath of the country, from Auckland and Coromandel Peninsula in the north to inland parts of the South Island north of Tekapo.The watch is in place already for the northern areas and kicks in from 1pm in the south.The watch also includes the Bay of Plenty, across the central high country to Taranaki, Whanganui southwards to northern and eastern parts of Wellington, and about the Tararua District and Wairarapa.MetService is scheduled to update the watch at 6pm.Severe thunderstorms would produce localised downpours of 25 to 40mm an hour, it said.Rainfall of this intensity can cause surface and/or flash flooding, especially about low-lying areas such as streams, rivers or narrow valleys, and may also lead to slips.Driving conditions would also be hazardous, with surface flooding and poor visibility in heavy rain, it said.