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Everyone is interested in the weather. In most countries, the weather bulletin is the most popular TV programme. People around the world need to know what the weather will be like today or tomorrow in order to know the possibilities for sowing, planting, harvesting crops, taking to sea or engaging in other travel, making preparations against impending natural hazards, such as hurricanes. They want to know the conditions for outside sporting events or recreational activities or, simply, what to wear and whether to take an umbrella.

Under the World Weather Watch of WMO, National Meteorological Services observe weather and climate around the clock and around the world, providing a steady flow of data which are then transmitted worldwide for forecasts and planning purposes. It is a unique system that networks observing stations to national, regional and global centres 24 hours a day in real-time, delivering data from the land surface and from space for forecasts and warnings for end-users and the public.

The weather knows no national boundaries and the work carried out by meteorologists, often behind the scenes for our benefit and safety is very much a team effort, hence the WMO slogan “Working together in weather, climate and water”.

WMO Members operate and coordinate their observational networks under the Global Observing System (GOS) that provides essential and unique observational data and information on the state of the Earth and its atmosphere. GOS is the most important operational global Earth observing system with end-to-end capability. Click here to see the Operational Newsletter for this observing system.

Observation systems within these networks collect meteorological, climatological, hydrological and marine and oceanographic data from more than 15 satellites, 100 moored buoys, 600 drifting buoys, 3 000 aircraft, 7 300 ships and some 10 000 land-based stations. Powerful computers use mathematical models based on physical laws to produce charts, digital products, weather and air-quality forecasts, climate predictions, risk assessments and early warning services. Meteorological satellites broadcast real-time weather information several times a day to more than 1 000 locations.

The observations and data help create products and forecasts and all of these are then transfered around the world through WMO's Global Telecommunication System (GTS). In this way, Members are enabled to provide reliable and effective weather services in support of safety of life and property, as well as the general welfare and well-being of their populations. Examples are safe, regular and efficient aviation operations, agriculture, fisheries and food security, shipping and safety at sea (, monitoring of water resources and early warning of natural hazards and community preparedness.

On average, a five-day weather forecast of today is as reliable as a two-day weather forecast 20 years ago. Click here for current weather forecasts for cities around the world and severe weather warnings. Despite this major scientific and technical progress, challenges remain and the accuracy of individual weather forecasts varies significantly. The challenges include characterizing and communicating the changing uncertainties in individual forecasts and advancing our forecasting skill in areas where progress has been difficult (e.g. heavy rainfall and the genesis, intensity and structure of tropical cyclones).

WMO’s World Weather Research Programme (WWRP) plays a leading role in addressing these challenges with a focus on weather events having large impacts on society, the economy and the environment. WWRP efforts cover time-scales ranging from hours to weeks and even months, in some cases. The largest WWRP activity is THORPEX (The Observing System Research and Predictability Experiment) that aims to accelerate improvements in both the accuracy and utilization of one-day to two-week forecasts of high-impact weather.





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