A widespread burst of thunderstorms tracked across Northland and Auckland early this morning - and more than 1300 lightning flashes were detected within an hour.
The hectic morning of weather comes after MetService issued a severe thunderstorm watch for Northland, Auckland, Great Barrier Island, and Coromandel Peninsula last night.
The warning extends until 9am today, with potentially damaging wind gusts of 110km/h or more to these areas, and heavy rain with intensities of 10-20mm/hr.
Showers with cold air will move onto the western parts of the North Island later in the morning, bringing a moderate risk of thunderstorms over western parts from Waitomo to southern Auckland.
During Sunday afternoon and evening, showers should continue to affect much of the North Island, especially western and northern parts.
Thunderstorms are possible from Taranaki to East Cape, and in the west from Taranaki to western Northland.
They may produce localised rainfall rates of 5-15mm/hr and small hail.
Cool conditions may bring snow to low levels over the South Island, and could affect the highest North Island roads.
Monday and Tuesday aren't looking much better, as a slow-moving front - expected to affect the central North Island - brings rain to many areas.
Rainfall amounts could reach warning criteria for the Coromandel Peninsula.
Significant amounts of rain are also expected for other North Island areas from about Auckland southeast to the central plateau and Hawke's Bay, but warning amounts are considered unlikely.
A front is expected to move northeast onto the southwest of the South Island on Thursday.
This front could bring warning amounts of rain to Fiordland.
Whangārei: Fine, but possible shower or two. Northwesterlies. High 19C / Low 10C.
Auckland: Few showers. Some possibly heavy and thundery. Northwesterlies. High 17C / Low 10C.
Tauranga: Rain clearing this morning, but a shower or two still possible. Northwesterlies from afternoon. High 16C / Low 8C.
Hamilton: Rain turning to a few showers this morning, chance heavy and thundery. Northwesterlies. High 16C / Low 7C.
New Plymouth: Rain then showers, chance heavy and thundery. Northeasterlies changing northwest. High 14C / Low 5C.
Napier: Rain developing this morning then easing this afternoon. Light winds. High 10C / Low 5C.
Wellington: Becoming cloudy morning. Showers from this afternoon, becoming isolated at night. Southerlies. High 11C / Low 5C.
Nelson: Cloud increasing. Occasional rain possible from early afternoon to evening. Gusty southerlies developing late morning. High 12C / Low 3C.
Christchurch: Showers and cold southerlies developing this morning. High 8C / Low 1C.
Dunedin: A shower or two. Cold southerlies dying out afternoon. High 7C / Low 4C.