Warnings and Forecasts
Warnings of Hazardous Weather Affecting Land Areas
As required, warnings are issued for:
- 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
Basic Public Forecasts
- Four short forecasts are issued daily, covering the next two days, for all of New Zealand
- Two extended short forecasts are issued daily, covering the following three days
- Two brief forecasts are issued daily for the mountain areas of New Zealand
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 25šS to 55šS (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, marine forecasts are issued for the Auckland marine area, Wellington Harbour and south coast, for inshore waters from 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
Emergencies
From time to time, emergencies may arise where specific users require urgent meteorological advice. The contract ensures that such advice will be available when needed. Such emergencies may include the need for weather information for national and international search and rescue operations, a fruit fly or a foot and mouth disease outbreak, volcanic eruptions and marine pollution incidents.
Meteorological Data Acquisition
Data Network
A data network is maintained which complies with recognised international standards as prescribed by the WMO. In particular, data are collected through
- Surface observations over New Zealand
- Upper air observations using a variety of means (ground-based equipment, aircraft, satellites)
- Weather surveillance radars
- Ships
- A network of around seven 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 communications circuits with no restrictions on use
- Public access to a particular set of observational data is made available at no charge through MetService's Internet web site. Online New Zealand meteorological data for the last 24 hours (available at www.metservice.co.nz/forecasts/observations.asp) includes:
- Surface observation 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, Wellington and Christchurch, 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 forecast services provided under the contract is passed to NIWA for archiving in the National Climate Database, at the marginal cost of transmission.
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
- Normally, the Chief Executive of the MetService or his designate, is the Permanent Representative of New Zealand with WMO, but the Minister of Transport may choose to appoint another person.
- Responsibilities of the Permanent Representative include:
- Forwarding information to other persons or agencies that are likely to be more appropriately involved in particular WMO issues or activities;
- Appointing both a hydrological and a climate advisor to provide guidance on these respective matters;
- Maintaining holdings of current WMO documents and allowing appropriate access by interested parties;
- Co-ordinating adherence by all Crown-funded meteorological service providers to the standards and procedures laid down by WMO.
Quality Assurance and Performance Standards
MetService must maintain certification under the ISO 9001 quality management system for the performance of services. In particular, MetService must:
- Operate a transparent system for verifying all severe weather warnings;
- Provide training and development programmes that ensure staff have the appropriate knowledge, skills and qualifications for their work;
- Employ forecasters who have proven experience and knowledge of New Zealand weather conditions and are based in New Zealand;
- Employ only forecasters that have successfully completed a course of training that fully satisfies the guidelines approved by WMO;
- Appoint a Chief Meteorologist with relevant post-graduate qualifications and a demonstrable record of professional integrity who is responsible for the technical oversight and maintenance of professional meteorological standards.
- Meet accuracy targets for warnings of heavy rain, heavy snow and severe gales. The targets require that 75% or greater of all types of severe weather events are correctly forecast, and that no more than 40% of all warnings issued turn out to be false alarms. However, there is also recognition that for low numbers of events these targets may not be achievable because of statistical variability.
