Severe Weather Outlook

Issued: 9:54am Sunday 19 Jan 2025

Valid Tuesday 21-Jan-2025

An intense low is expected to move slowly south over the far north and direct a moist easterly flow onto the upper North Island. Watches for severe gales and heavy rain have already been issued.
There is high confidence that warning amounts of rain will accumulate in Northland and Coromandel, moderate confidence for Auckland and low confidence for the north of Gisborne/Tairawhiti. There is moderate confidence that severe southeasterly gales will affect Northland and low confidence that severe easterly gales will affect Auckland.



A low pressure system affects the upper North Island, with a strong and moist easterly flow spreading farther south across the North Island.
There is low confidence that rainfall accumulations could approach warning criteria about Northland, Auckland, Coromandel Peninsula, western Bay of Plenty and northern Gisborne/Tairawhiti. However, confidence increases to moderate for eastern parts of Northland for a time in the morning, for Great Barrier Island, Coromandel Peninsula and far western Bay of Plenty for much of the day, and for the far north of Gisborne/Tairawhiti late in the day.
There is also low confidence that easterly gales could become severe from Northland to northern Waikato, about Coromandel Peninsula, western Bay of Plenty and also about far northern Gisborne/Tairawhiti.

Valid Wednesday 22-Jan-2025

A moist southeast flow is likely to affect the east of the North Island.
There is low confidence of rainfall accumulations reaching warning criteria about Gisborne/Tairawhiti.

Valid Thursday 23-Jan-2025

A front moves east onto the lower South Island. Warning amounts of rain area not likely to accumulate. There is minimal risk of severe weather.

Valid Friday 24-Jan-2025

A ridge of high pressure is likely to bring settled weather to much of the country. There is minimal risk of severe weather.

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 Monday, 20-Jan-2025

Issued: 8:10am Monday 20 Jan 2025

A broad area of low pressure lies north of New Zealand today, with an embedded subtropical low moving towards the north of the country late in the day. An associated strong humid easterly flow covers the northern North Island with rain and showers. Severe Weather Watches and Warnings for heavy rain and possible severe gales are in force for the north of the North Island. For more detail, see https://www.metservice.com/warnings/home. The risk of thunderstorms over northern Northland generally increases during the day. There is a low risk of thunderstorms this morning and early afternoon over northern Northland, then a moderate risk from mid-late afternoon onwards. A low risk covers southern Northland all day. Any thunderstorms that occur will produce localised heavy rain of 10-25 mm/h (or possibly more), with a low risk of severe thunderstorms and localised downpours of 25-50 mm/h over northern Northland tonight. Daytime cloud buildups are also expected to produce isolated showers about the inland South Island today. There is an associated low risk of a few thunderstorms about the Queenstown Lakes district, inland parts of Fiordland and southern Westland in the late afternoon and evening. No other thunderstorms or significant convection expected over New Zealand today.



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.