Issued at 2:05pm 29/03/2024
Valid from 2:05pm 29/03/2024 to 1:00am 30/03/2024
An unstable showery south to southwest flow covers New Zealand. During the morning there is a low risk of a few thunderstorms about far eastern Taranaki, Whanganui, Taihape, Manawatu, Wairarapa and Hawke's Bay. During the afternoon the low risk spreads northwards to Gisborne/Tairawhiti, Bay of Plenty and eastern Waikato, as indicated on the chart. From then there is also a moderate risk of a few thunderstorms about Hawke's Bay north of about Napier, eastern Taupo, Gisborne/Tairawhiti and eastern Bay of Plenty. Any thunderstorms that develop will bring brief heavy rain and small hail. No other thunderstorms or significant convection expected elsewhere on Good Friday.
Issued at 8:06pm 29/03/2024
Valid from 1:00am 30/03/2024 to 1:00pm 30/03/2024
An unstable south to southwest flow affects the east coast of the North Island on Saturday morning with a low risk of thunderstorms from coastal Wairarapa northwards through Hawke's Bay and Tairawhiti/Gisborne. A trough moves through the area during this time, bringing a moderate risk of thunderstorms to the Wairoa District and southern Gisborne/Tairawhiti, as indicated on the chart. Any thunderstorms that occur will bring brief heavy rain and possibly small hail. No thunderstorms or significant convection expected elsewhere during this period.
Issued at 10:20am 29/03/2024
Valid from 1:00pm 30/03/2024 to 1:00am 31/03/2024
A low risk of thunderstorms persist for the first few hours of the afternoon in Hawke's Bay and Tairawhiti/Gisborne before conditions stabilise. However, a low risk returns to Mahia Peninsula and coastal Gisborne/Tairawhiti at night when a trough affects these areas. No thunderstorms or significant convection expected elsewhere during this period.
In New Zealand, MetService classifies a thunderstorm as severe if one or more of the following criteria are met:
Rainfall of 25mm/h, or more.
Hailstones 20mm in diameter, or larger.
Gusts of 110km/h (60 knots) or stronger.
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.