Severe Weather Outlook

Valid from Friday 09-Jun-2023 to Sunday 11-Jun-2023

Issued: 10:12am Wednesday 7 Jun 2023

A southeasterly flow lies over northern and central New Zealand. This flow is expected to weaken on Saturday and Sunday as a slow-moving low east of the North Island moves away from the country. A rain-band embedded within the flow moves southwards onto the eastern North Island on Friday and Saturday.

There is low confidence that rainfall will reach warning criteria about Tairawhiti/Gisborne and Hawke's Bay north of about Waipukurau on Friday, then moderate confidence on Saturday. There is also low confidence that warning amounts of rain will spread further west and south into the hills and ranges of eastern Bay of Plenty, Taupo, Taihape, Manawatu, the rest of Hawke's Bay, Tararua District and Wairarapa on Saturday.

The rain-band is expected to weaken late Saturday.

A series of fronts should cross the south of the South Island during Sunday and Monday. There is low confidence that the fronts will bring warning amounts of rain to Fiordland on Sunday and Monday.

Low confidence:

a 20% likelihood (or 1 chance in 5) that the event will actually happen.

Moderate confidence:

a 40% likelihood (or 2 chances in 5) that the event will actually happen.

High confidence:

a 60% likelihood (or 3 chances in 5) that the event will actually happen.

New issues of this forecast are made available on this site at or before 16:30 NZST

Thunderstorm Outlook

Valid to Midnight Wednesday, 07-Jun-2023

Issued: 7:05am Wednesday 7 Jun 2023

No thunderstorms or significant convection expected during this period.



Valid to Noon Thursday, 08-Jun-2023

Issued: 9:02am Wednesday 7 Jun 2023

No thunderstorms or significant convection expected during this period.



Valid to Midnight Thursday, 08-Jun-2023

Issued: 9:04am Wednesday 7 Jun 2023

No thunderstorms or significant convection expected 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 25 millimetres per hour, or more.

Large hail:

Hailstones 20 millimetres in diameter, or larger.

Strong wind gusts (from thunderstorms):

Gusts of 110 kilometres per hour / 60 knots or stronger.

Damaging tornadoes:

Fujita F1 (wind speeds greater than 116 kilometres per hour / 63 knots) or stronger.