Auckland's thunderstorm risk is slowly easing after heavy downpours and cloud-to-ground lightning strikes across parts of north and west Auckland.
"Unstable atmospheric conditions" caused thunderstorms to build up over the city on Tuesday, which brought heavy rain.
MetService issued a severe thunderstorm watch for threatening weather conditions earlier in the day. These are decreasing, but the threat is expected to last until evening.
"Scattered heavy showers and thunderstorms are affecting Auckland and Coromandel Peninsula this afternoon," MetService says.
"There is a moderate risk of these thunderstorms becoming severe, producing localised downpours of 25 to 40mm/hr and large hail with diameter in excess of 2cm."
A Waitakere rain gauge has collected 22.6mm of rain in just one hour, MetService says.
Lightning lashed the area over and west of Orewa, with NIWA tracking multiple lightning strikes just after 1pm. It's issued a warning to the public to take care.
"Note several cloud-to-ground lightning strikes in the 5 minutes ending at 1:15 pm," it tweeted.
"Remember to stay indoors when there is lightning and certainly stay off the water."
Images posted to social media show massive cumulus clouds forming around Auckland.
Weather Watch says the downpours are slow-moving and heavy enough to cause "dangerous flash and surface flooding".