Severe Weather Outlook
Issued: 9:54am Sunday 19 Jan 2025
Valid Tuesday 21-Jan-2025
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
There is low confidence of rainfall accumulations reaching warning criteria about Gisborne/Tairawhiti.
Valid Thursday 23-Jan-2025
Valid Friday 24-Jan-2025
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
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.