Thunderstorm Outlook
Issued at 7:48am 6/06/2026
Valid from 7:48am 6/06/2026 to Midnight 6/06/2026
An unstable westerly flow covers the North Island today, while a cold front and southerly wind change moves northwards over central New Zealand. For Northland and Auckland, there is a moderate risk of a few thunderstorms about western areas this morning, and a low risk elsewhere through to this afternoon. Brief heavy rain of 5-15 mm/h and hail of 5-15 mm diameter will accompany the thunderstorms. For eastern Bay of Plenty, there is a moderate risk of a few thunderstorms east of Opotiki this morning and afternoon, with brief heavy rain of 5-15 mm/h and small hail. For western North Island areas from about Raglan to Paraparaumu, there is a moderate risk of a few thunderstorms from late morning through until early evening, with brief heavy rain of 5-15 mm/h and hail of 5-15 mm diameter. For Marlborough and eastern parts of Nelson (including Nelson city), there is a moderate risk of a few thunderstorms for a time mid or late afternoon, with brief heavy rain of 5-15 mm/h and hail of 5-10 mm diameter. For coastal parts of Southland and Clutha, there is a moderate risk of one or two thunderstorms from this evening, with brief heavy rain of 5-10 mm/h, and hail of 5-10 mm diameter. Also, although not depicted on the chart, there is a moderate risk of a few thunderstorms at the Chatham Islands around the middle of the day with brief heavy rain. A low risk covers many other areas as indicated on the chart.
Issued at 8:26am 6/06/2026
Valid from Midnight 6/06/2026 to Midday 7/06/2026
A showery southwest flow covers New Zealand on Sunday morning, with embedded fronts moving northwards along the east coast of both islands. As indicated on the chart, there is a low risk of a few thunderstorms about Canterbury, southern Wellington, Wairarapa, Buller and far western Tasman before dawn, and about coastal parts of Hawke's Bay (including the Wairoa district) later in the morning. There is a minimal risk of thunderstorms over other parts of New Zealand on Sunday morning.
Severe Thunderstorm Criteria
In New Zealand, MetService classifies a thunderstorm as severe if one or more of the following criteria are met:
Heavy rain (from thunderstorms):
Rainfall of 25mm/h, or more.
Large hail:
Hailstones 20mm in diameter, or larger.
Strong wind gusts (from thunderstorms):
Gusts of 110km/h (60 knots) or stronger.
Damaging tornadoes:
Fujita F1 - i.e. wind speeds greater than 116km/h (63 knots) or stronger.
Note: some tornadic systems such as funnel clouds, waterspouts and small land-based tornadoes are possible with thunderstorms that may not be classified as severe.
