Thunderstorm Outlook
Issued at 9:04am 25/06/2026
Valid from 9:04am 25/06/2026 to Midnight 25/06/2026
A complex low over the northern North Island is forecast to move slowly eastwards today. This afternoon there is a moderate risk of thunderstorms for the far south of Coromandel Peninsula, and for much of Bay of Plenty, Waikato and Waitomo, as drawn on the chart. Any thunderstorms that occur will likely be accompanied by heavy rain with intensities of 10 to 25 mm/h, and small hail. There is a low risk of thunderstorms for Northland this morning and tonight, and for Auckland, Great Barrier Island, Coromandel Peninsula, Bay of Plenty, and Gisborne/Tairawhiti north of Gisborne City all day. For Waikato, Waitomo, Taumarunui, Taupo, Gisborne/Tairawhiti from Gisborne City southwards, and Hawke's Bay north of Napier, there is a low risk of thunderstorms this afternoon and early evening, as depicted on the chart. There is minimal risk of thunderstorms or significant convection expected elsewhere in New Zealand today.
Issued at 9:35am 25/06/2026
Valid from Midnight 25/06/2026 to Midday 26/06/2026
A complex low is forecast to linger to the northeast of the North Island, with an associated trough expected to move eastwards across northern New Zealand during the early hours of Friday morning. Before dawn there is mostly a low risk of thunderstorms for Coromandel Peninsula north of Tairua, Auckland, Great Barrier Island, and Northland, but the risk is considered moderate for the west of Northland, as drawn of the chart. Any thunderstorms that occur will likely be accompanied by heavy rain with intensities of 10 to 15 mm/h, and small hail. There is a low risk of thunderstorms for Gisborne/Tairawhiti throughout the morning. There is minimal risk of thunderstorms or significant convection elsewhere in New Zealand during Friday 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.
