Thunderstorm Outlook
Issued at 7:56am 26/01/2026
Valid from 7:56am 26/01/2026 to 1:00am 27/01/2026
A combination of wind convergence and afternoon and early evening heating is expected to bring a low risk of a few thunderstorms to central and eastern parts of the country from Hawke's Bay to Marlborough and much of Nelson/Tasman, also across Canterbury High Country to northern Queenstown Lakes, and inland parts of Westland, Grey and Buller. However, the risk of thunderstorms is considered moderate for Hawke's Bay south of SH5, Taihape and the Tararua District. Over the South Island the moderate risk extends through much of Marlborough, Nelson Lakes and down through the Southern Alps to about Mt Cook. These thunderstorms may produce localised rainfall rates of 10 to 20 mm/h and small hail. There is minimal risk of thunderstorms or significant convection expected elsewhere during this period.
Issued at 8:29am 26/01/2026
Valid from 1:00am 27/01/2026 to 1:00pm 27/01/2026
A southerly change moves over southern Wairarapa, Wellington and the Marlborough Sounds before dawn on Tuesday, and there is an associated low risk of thunderstorms as indicated on the chart. There is minimal risk of thunderstorms or significant convection expected elsewhere during this period.
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.
