Met Office

© Image: Met Office (United Kingdom)
Logo of the United Kingdom's Met Office

The Met Office (originally an abbreviation for Meteorological Office, but now the official name in itself), which has its headquarters at Exeter in Devon, is the United Kingdom's national weather service and an executive agency of the Ministry of Defence.

Locations

(CC) Photo: William M. Connolley
The Met Office headquarters in Exeter

In 2003, the Met Office moved its headquarters to Exeter in Devon from its previous location of Bracknell in Berkshire. Part of the Met Office complex in Exeter is the Met Office College, which handles the training for internal personnel and many forecasters from around the world. The Hadley Centre for Climate Prediction and Research is also part of the Exeter complex.

The Met Office now has a worldwide presence, including a forecasting center in Aberdeen and offices in Gibraltar and in the Falkland Islands.

Other parts of the Met Office are:

• The Joint Centre for Mesoscale Meteorology] (JCMM) at University of Reading in Berkshire

• The Joint Centre for Hydro-Meteorological Research] (JCHMR) site at Wallingford in Oxfordshire

• A Met Office presence at many Army and Air Force bases within the UK and abroad.

History

Established in 1854 as a small department within the Board of Trade as a service to mariners. The loss of the passenger vessel the Royal Charter and 459 lives off the coast of Anglesey in a violent storm in October 1859 led to the first gale warning service. In 1861,a network of 15 coastal stations was established from which visual gale warnings could be provided for ships at sea.

The development of the electric telegraph in the 1870's led to the more rapid dissemination of warnings and also led to the development of an observational network which could then be used to provide synoptic analyses. In 1879 the Met Office started providing forecast to newspapers.

Following the First World War the Met Office later became part of the Air Ministry in 1920. In 1922, weather forecasts are broadcast by BBC radio for the first time.

In 1936, the Royal Navy began providing their own forecasts and the Met Office no longer provides services to them.

In 1990, the Met Office became an Executive Agency of the Ministry of Defence. Also, the Hadley Centre for Climate Prediction and Research was opened in that same year.

The Met Office's new headquarters in Exeter were officially opened in 2004. The Met Office now has a quasi-governmental role, being required to act commercially as well as being an executive agency of the Ministry of Defence.

Forecasts

The Shipping Forecast

One of the British stalwarts, the Shipping Forecast, is produced by the Met Office and broadcast on BBC Radio 4. The Shipping Forecast has long been of real interest to, and vital to the safety of, mariners traversing the sea areas around the British Isles and its broadcast on radio is still avidly listened to. Less importantly, the Shipping Forecast has been the subject of both books and song lyrics.

Weather Forecasting and Warnings

The Met Office has the responsibility to issue severe weather warnings for the United Kingdom through the National Severe Weather Warning Service (NSWWS). These are weather events that may affect transport infrastructure or endanger people's lives. In March 2008, the system was improved and a new stage of warning called the "Advisory" was introduced.

The main role of the Met Office is to produce forecasts by gathering data from satellites in space and from observations on Earth and processing that data using supercomputers. The processed forecast data are then passed on to companies who acquire it. In particular, two of the main media companies, the BBC and ITV broadcast forecasts using the Met Office's data. This is mainly how the public are informed of weather events which may affect day-to-day life.

World Area Forecast Center

The Met Office is also one of only two World Area Forecast Centers or WAFCs, and is referred to as the London WAFC. The other WAFC is located in [[Missouri]], U.S. but known as the Washington WAFC. WAFC data are used daily to safely route aircraft, particularly on long-haul journeys. The data provide details of wind speed and direction, air temperature, cloud type and tops, and other features of interest to the aviation community, such as volcanic ash eruptions.

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Air Quality

The Met Office issues air quality forecasts made using NAME, the Met Office's medium-to-long-range atmospheric dispersion model. It was originally developed as a nuclear accident model following the Chernobyl accident in 1986, but has since evolved into an all-purpose dispersion model capable of predicting the transport, transformation and deposition of a wide class of airborne materials. NAME is used operationally by the Met Office as an emergency response model as well as for routine air quality forecasting.

In the air quality forecasts, the level of pollution is described either as an index (ranging from 1 to 10) or as a banding (low, moderate, high or very high). These levels are based on the health effects of each pollutant as shown just below.

Index	Banding	Health Effect
1–3	Low	Effects are unlikely to be noticed even by individuals who know they are sensitive to air pollutants.
4–6	Moderate	Mild effects, unlikely to require action, may be noticed amongst sensitive individuals.
7-9	High	Significant effects may be noticed by sensitive individuals and action to avoid or reduce these effects may be needed (e.g. reducing exposure by spending less time in polluted areas outdoors). Asthmatics will find that their 'reliever' inhaler is likely to reverse the effects on the lung.
10	Very High	The effects on sensitive individuals described for 'High' levels of pollution may worsen.

The forecast is produced for a number of different pollutants and their typical health effects are shown in the following table.

Pollutant	Health Effects at High Level
Nitrogen dioxide Ozone Sulfur dioxide	These gases irritate the airways of the lungs, increasing the symptoms of those suffering from lung diseases.
Particulates	Fine particles can be carried deep into the lungs where they can cause inflammation and a worsening of heart and lung diseases