Severe Weather Outlook

Issued: 10:53am Saturday 22 Jun 2024

Valid Monday 24-Jun-2024

Slow moving low lies west of Aotearoa New Zealand, with an associated front delivering some rain and easterlies to the lower South Island. Meanwhile, another low is expected to move southward during the day, just east of the upper North Island, and deepen. This low is forecast to lie near East Cape late in the day, bringing a burst of rain to eastern Bay of Plenty and northern parts of Gisborne.
There is a low confidence that the burst of rain about western Bay of Plenty and northern Gisborne will approach warning amounts later in the day. The rainfall amounts about eastern parts of the lower South Island are not expected to reach warning amounts at this stage.

Valid Tuesday 25-Jun-2024

The low near East Cape is forecast to continue slowly south and lie east of the North Island, delivering strong south to southwesterlies and rain over the North Island.
Meanwhile, the rain over the lower South Island eases, as the slow moving low west of the country weakens.

There is a moderate confidence of warnable amounts of rain about eastern parts of Hawkes Bay (south of Napier) and the Wairarapa, with a low confidence about remaining parts of Hawkes Bay, also Tairawhiti/Gisborne south of Ruatoria.
In addition, there is a low risk of severe southwest gales affecting coastal parts of Hawkes Bay north of Napier, also southern Tairawhiti/Gisborne.

Valid Wednesday 26-Jun-2024

The low is forecast to make slow progress eastward, showers and rain persist about eastern parts of the North Island, also affecting the top of the South Island.
There is a low confidence that rainfall accumulations will reach warning amounts about southern parts of Tairawhiti/Gisborne, and about Hawkes Bay (mainly near the coast south of Napier), with a low confidence of severe southwest gales about coastal areas.

Valid Thursday 27-Jun-2024

Southerlies slowly ease about the North Island, although showers persist through the morning with a low confidence of warnable amounts of rain about the Wairoa District.
A narrow ridge of high pressure covers the remainder of the country, however, a weak front is expected to approach the lower South Island later in the day.

Low confidence:

A 20% likelihood (or 1 chance in 5) of a warning being issued.

Moderate confidence:

A 40% likelihood (or 2 chances in 5) of a warning being issued.

High confidence:

a 60% likelihood (or 3 chances in 5) of a warning being issued.

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

Thunderstorm Outlook

Valid to Midnight Saturday, 22-Jun-2024

Issued: 7:38am Saturday 22 Jun 2024

A low and associated front lie offshore to the west of New Zealand. There is a low risk of thunderstorms about parts of Taranaki, much of Tasman and far northern Buller from afternoon, and for Northland from evening. No other areas of significant convection or thunderstorms are expected.



Valid to Noon Sunday, 23-Jun-2024

Issued: 10:27am Saturday 22 Jun 2024

A front moves over central and northern New Zealand from the west, bringing widespread rain. Watches and Warnings for Heavy Rain are in place. There is a low risk of thunderstorms embedded in this rain for many central and northern parts of the country, as indicated on the chart. However, for Auckland, Coromandel Peninsula, far western Bay of Plenty, coastal Waikato and Waitomo, Taranaki and much of Tasman the risk of thunderstorms is considered moderate. Any thunderstorms that occur will enhance local rainfall rates (up to 25 mm per hour) and there is also a low risk of localised downpours (25 to 40 mm per hour). No thunderstorms or significant convection expected elsewhere during the first half of Sunday.



Valid to Midnight Sunday, 23-Jun-2024

Issued: 10:35am Saturday 22 Jun 2024

A low risk of embedded thunderstorms persists for many central and northern areas during the second half of Sunday as a front and associated rain band move eastwards, as indicated on the chart. However, the risk is considered moderate for Bay of Plenty and far northern Gisborne during the afternoon and evening. Any thunderstorms that occur will enhance local rainfall rates (up to 25 mm per hour) and there is also a low risk of localised downpours (25 to 40 mm per hour). No thunderstorms or significant convection expected elsewhere during the second half of Sunday.



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.