National Weather Services
MetService is New Zealand’s designated National Meteorological Service with the World Meteorological Organisation. Under contracts with the Crown, MetService is the only authorised provider of Severe Weather Warnings and other public safety weather services to the people of New Zealand, as well as certified weather information to the aviation industry and all airlines flying into and within New Zealand.
Protecting the Public
MetService provides publicly-available marine forecasts, mountain forecasts and the short forecasts for NZ:
- For all of New Zealand: four short forecasts are issued daily, covering the next two days, and two extended short forecasts are issued daily, covering the following three days.
- For the mountain areas of New Zealand: Two brief forecasts are issued daily, covering the next two days, and two extended brief forecasts are issued daily, covering the following three days.
Marine Forecasts and Warnings
- Warnings of gales, storms and hurricanes are issued as required for the Tasman Sea and a large part of the South Pacific Ocean, extending halfway to South America, and from latitude 25°S to 55°S (roughly 6% of the world's oceans)
- Twice daily, synopses and forecasts are issued for the same area
- Four times daily, detailed marine warnings and forecasts are issued for the coastal waters of New Zealand (up to 100 km from the coast) and the Chatham Islands (the precise areas covered for these coastal services are as specified in the New Zealand Nautical Almanac)
- Warnings of near gales (25 to 33 knots) are issued as required for the Auckland marine area - Manukau and Waitemata harbours and the Hauraki Gulf south of a line from Cape Colville to Bream Head.
- Four times daily, inshore marine forecasts are issued for the Bay of Islands, Auckland marine area, eastern Coromandel, Wellington Harbour and south coast, for Waitarere to Pukerua Bay, and for Pegasus Bay from the mouth of the Waimakariri River to Lyttelton Harbour
- MetService operates a radio-facsimile service broadcasting marine weather charts over the Pacific Ocean south of the equator
- MSL analysis and forecast charts are made available on this website
Warnings of Hazardous Weather Affecting Land Areas
Warnings are sent to the media and civil authorities in the affected area whenever a specified list of weather conditions is expected. These conditions include widespread heavy rain, or heavy snow to low levels, or very strong winds or gusts. Alerts may also be issued for damaging swells on the coast, or unusually high sea water (storm surge). Warnings may also be issued for less severe conditions if the region to be affected has recently suffered severe weather - such as in an area where more rain may increase risk of flooding.
Severe Weather Warnings are issued if the following weather is expected within the next day or so:
- Widespread heavy rain, exceeding 50 mm in 6 hours or 100 mm in 24 hours
- Widespread heavy snowfalls below 1000 metres on the North Island and 500 metres on the South Island, exceeding a depth of 10 cm in 6 hours or 25 cm in 24 hours
- Widespread severe gales with a sustained wind speed of 90 km/hr or more, or frequent gusts of 110 km/hr or more
- Heavy coastal swells, according to agreed criteria for certain regional authorities
In addition, Severe Thunderstorm Warnings are issued for specific thunderstorm cells that are able to be tracked on our radar network and that meet severe thunderstorm criteria:
- Heavy rain (from thunderstorms) bringing rainfall of 25 millimetres per hour or greater
- Hailstones 20 millimetres in diameter or greater
- Strong wind gusts (from thunderstorms) of 110 kilometres per hour (60 knots) or greater
- Damaging tornadoes: Fujita F1 or greater, where F1 is defined as having wind speeds greater than 116 kilometres per hour (63 knots)
Severe Thunderstorm Watches are issued when conditions are favourable for severe thunderstorms in and close to the watch area, and are usually issued 1 to 6 hours ahead depending on the situation. People in the Watch areas should be on the lookout for threatening weather conditions and listen for possible Severe Thunderstorm Warnings. Severe Thunderstorm Outlooks are issued daily, describing the thunderstorm risk expected over the next 48 hours.
A free email subscription service covering ALL severe weather information is available: sign up here.
From time to time, emergencies may arise where urgent meteorological advice is needed, such as weather information for national and international search and rescue operations; a fruit fly or foot and mouth disease outbreak; volcanic eruptions; and marine pollution incidents. MetService works closely with the relevant agencies - such as Civil Defence, NZ Police and Maritime NZ - to ensure that this information is on hand when it's needed.
MetService operates a comprehensive observing network over and around New Zealand which complies with recognised international standards as prescribed by the WMO. This includes data collected from:
- Surface observations over New Zealand (automatic weather stations)
- Upper air observations using a variety of means (ground-based equipment, aircraft, satellites)
- Weather surveillance radars
- A network of drifting buoys in the Tasman Sea
Data Distribution and Availability
Observational data from the Regional Basic Synoptic Network as defined by WMO is freely distributed internationally through WMO with no restrictions on use. In addition, public access to a particular set of observational data is made available at no charge through this web site.
Online New Zealand meteorological data for the last 24 hours includes:
- Surface observations from at least 40 stations, updated 3 hourly;
- All upper wind, temperature and humidity observations from New Zealand ground based stations;
- Weather radar images from Auckland, Bay of Plenty, Gisborne/Hawke's Bay, Taranaki, Wellington, Canterbury and Southland, updated every 3 hours;
- Weather satellite images covering the eastern Australia-Tasman Sea-New Zealand region, updated every 3 hours.
All observational data gathered in direct support of the public forecast services provided under MetService's contract with the Ministry of Transport is also passed to NIWA for archiving in the National Climate Database.
Support Services to the Pacific
MetService continues to maintain close links with the meteorological agencies of various Pacific Island states and, as far as possible, to monitor the quality and integrity of data gathered from the Pacific Islands, and provide appropriate technical advice.
All warnings of hazardous weather for the South Pacific region, normally received from the Nadi Tropical Cyclone Warning Centre, are forwarded to Radio New Zealand International and to the Ministry of Foreign Affairs and Trade.
MetService provides backup for the main warnings and forecasting responsibilities of the Nadi Tropical Cyclone Warning Centre, should that Centre temporarily shut down or be cut off, possibly due to a direct hit by a cyclone.
World Meteorological Organization
All weather forecasting relies on international co-operation and exchange of data. The world's National Meteorological and Hydrological Services work with the World Meteorological Organization (WMO), the United Nations' authoritative voice on weather, climate and water. Their combined efforts are essential for the maintenance and improvement of global weather observations, meteorological services and meteorological research, and for ensuring their contributions to the protection of life, property and the environment and to sustainable development.
The Chief Executive of MetService or his designate is the Permanent Representative of New Zealand with WMO.
MetService sends data gathered from the New Zealand region to other WMO member countries around the world. This is used as input to sophisticated computer models at major centres such as London and Washington. These models build pictures of the world weather, and forecast how weather patterns should change over the next week or more.
MetService forecasters have access to the best global models and high-resolution regional models, which are integrated into our day-to-day forecasting process. Global model data is accessed through agreements with overseas modelling centres, while MetService’s Forecasting Research team develops and maintains a suite of high-resolution, local-area models.
For more information on the work of WMO relating to weather, visit their website: http://public.wmo.int/en/our-mandate/weather