Thunderstorm Outlook
Issued at 8:24am 14/08/2026
Valid from 8:24am 14/08/2026 to Midnight 14/08/2026
A low near Northland is moving slowly southeast. Fronts associated with the low are bringing rain to Northland, Bay of Plenty and northern Gisborne/Tairawhiti. There is a moderate risk of thunderstorms about eastern Bay of Plenty and northern Gisborne/Tairawhiti this morning and afternoon. These thunderstorms may bring localised heavy rain with intensities of 10 to 25 mm per hour and there is a low risk of downpours of 25 to 40 mm per hour. A low risk of thunderstorms exists until tonight over the whole Bay of Plenty region and south of the moderate risk area in Gisborne/Tairawhiti. For Northland, there is a low risk thunderstorms until tonight, with a low risk of localised downpours this morning and afternoon. About inland Taranaki and east to about Ohakune, there is a low risk of thunderstorms this afternoon. Elsewhere, the risk of severe convection or thunderstorms is minimal.
Issued at 10:16am 14/08/2026
Valid from Midnight 14/08/2026 to Midday 15/08/2026
A large low over the North Island slowly moves off to the east. There is a low risk of thunderstorms about Gisborne/Tairawhiti north of Gisborne City during the morning. Elsewhere, the risk of severe convection or thunderstorms is minimal.
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.
