World Meteorological Organization in the context of Kilopascal

In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, ice crystals, or other particles, suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may comprise the droplets and crystals. On Earth, clouds are formed as a result of saturation of the air when it is cooled to its dew point, or when it gains sufficient moisture, usually in the form of water vapor, from an adjacent source to raise the dew point to the ambient temperature.

Clouds are seen in the Earth's homosphere, which includes the troposphere, stratosphere, and mesosphere.Nephology is the science of clouds, which is undertaken in the cloud physics branch of meteorology. The World Meteorological Organization uses two methods of naming clouds in their respective layers of the homosphere, Latin and common name.

Haze is traditionally an atmospheric phenomenon in which dust, smoke, and other dry particulates suspended in air obscure visibility and the clarity of the sky. The World Meteorological Organization manual of codes includes a classification of particulates causing horizontal obscuration into categories of fog, ice fog, steam fog, mist, haze, smoke, volcanic ash, dust, sand, and snow. Sources for particles that cause haze include farming (stubble burning, ploughing in dry weather), traffic, industry, windy weather, volcanic activity and wildfires.Seen from afar (e.g. an approaching airplane) and depending on the direction of view with respect to the Sun, haze may appear brownish or bluish, while mist tends to be bluish grey instead. Whereas haze often is considered a phenomenon occurring in dry air, mist formation is a phenomenon in saturated, humid air. However, haze particles may act as condensation nuclei that leads to the subsequent vapor condensation and formation of mist droplets; such forms of haze are known as "wet haze".

In meteorological literature, the word haze is generally used to denote visibility-reducing aerosols of the wet type suspended in the atmosphere. Such aerosols commonly arise from complex chemical reactions that occur as sulfur dioxide gases emitted during combustion are converted into small droplets of sulfuric acid when exposed. The reactions are enhanced in the presence of sunlight, high relative humidity, and an absence of air flow (wind). A small component of wet-haze aerosols appear to be derived from compounds released by trees when burning, such as terpenes. For all these reasons, wet haze tends to be primarily a warm-season phenomenon. Large areas of haze covering many thousands of kilometers may be produced under extensive favorable conditions each summer.

The Intergovernmental Panel on Climate Change (IPCC) is an intergovernmental body of the United Nations. Its job is to "provide governments at all levels with scientific information that they can use to develop climate policies". The World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) set up the IPCC in 1988. The United Nations endorsed the creation of the IPCC later that year. It has a secretariat in Geneva, Switzerland, hosted by the WMO. It has 195 member states who govern the IPCC. The member states elect a bureau of scientists to serve through an assessment cycle. A cycle is usually six to seven years. The bureau selects experts in their fields to prepare IPCC reports. There is a formal nomination process by governments and observer organizations to find these experts. The IPCC has three working groups and a task force, which carry out its scientific work.

The IPCC informs governments about the state of knowledge of climate change. It does this by examining all the relevant scientific literature on the subject. This includes the natural, economic and social impacts and risks. It also covers possible response options. The IPCC does not conduct its own original research. It aims to be objective and comprehensive. Thousands of scientists and other experts volunteer to review the publications. They compile key findings into "Assessment Reports" for policymakers and the general public; Experts have described this work as the biggest peer review process in the scientific community. The IPCC was the first of three global science policy panels to be established, followed by and IPBES (Intergovernmental Platform on Biodiversity and Ecosystem Services), established in 2012 and the Intergovernmental Science-Policy Panel on Chemicals, Waste and Pollution (ISPCWP) established in 2025.

The pascal (symbol: Pa) is the unit of pressure in the International System of Units (SI). It is also used to quantify internal pressure, stress, Young's modulus, and ultimate tensile strength. The unit, named after Blaise Pascal, is an SI coherent derived unit defined as one newton per square metre (N/m). It is also equivalent to 10 barye (10 Ba) in the CGS system. Common multiple units of the pascal are the hectopascal (1 hPa = 100 Pa), which is equal to one millibar, and the kilopascal (1 kPa = 1,000 Pa), which is equal to one centibar.

The unit of measurement called standard atmosphere (atm) is defined as 101325 Pa.Meteorological observations typically report atmospheric pressure in hectopascals per the recommendation of the World Meteorological Organization, thus a standard atmosphere or typical sea-level air pressure is about 1,013 hPa. Reports in the United States typically use inches of mercury or millibars (hectopascals). In Canada, these reports are given in kilopascals.

Charles Warren Thornthwaite (March 7, 1899 – June 11, 1963) was an American geographer and climatologist. He is best known for devising the Thornthwaite climate classification, a climate classification system modified in 1948 that is still in use worldwide, and also for his detailed water budget computations of potential evapotranspiration.

He was Professor of Climatology at Johns Hopkins University, adjunct professor at Drexel University, President of the Commission for Climatology of the World Meteorological Organization, a recipient of the Outstanding Achievement Award of the Association of American Geographers, and the Cullum Geographical Medal from the American Geographical Society.

A Regional Specialized Meteorological Centre (RSMC) is responsible for the distribution of information, advisories, and warnings regarding the specific program they have a part of, agreed by consensus at the World Meteorological Organization as part of the World Weather Watch.

The Japan Meteorological Agency (Japanese: 気象庁, Hepburn: Kishō-chō; JMA) is a division of the Ministry of Land, Infrastructure, Transport and Tourism dedicated to the scientific observation and research of natural phenomena. Headquartered in Minato, Tokyo, the agency collects data on meteorology, hydrology, seismology, volcanology, and other related fields.

The JMA is responsible for collecting and disseminating weather data and forecasts to the public, as well as providing specialized information for aviation and marine sectors. Additionally, the JMA issues warnings for volcanic eruptions and is integral to the nationwide Earthquake Early Warning (EEW) system. As one of the Regional Specialized Meteorological Centers designated by the World Meteorological Organization (WMO), the JMA also forecasts, names, and distributes warnings for tropical cyclones in the Northwestern Pacific region. This includes areas such as the Celebes Sea, the Sulu Sea, the South China Sea, the East China Sea, the Yellow Sea, the Sea of Japan, and the Sea of Okhotsk.

Nowcasting is weather forecasting on a very short term mesoscale period of up to 2 hours, according to the World Meteorological Organization, and up to six hours, according to other authors in the field. This forecast is an extrapolation in time of known weather parameters, including those obtained by means of remote sensing, using techniques that take into account a possible evolution of the air mass. This type of forecast therefore includes details that cannot be solved by numerical weather prediction (NWP) models running over longer forecast periods.

A weather drone, or weather-sensing uncrewed aerial vehicle (UAV), is an unmanned aircraft carrying sensors that collect thermodynamic and kinematic data from the mid and lower atmosphere (e.g. up to 6 km).

Weather drones are not yet used to support National Meteorological and Hydrological Services (NMHS) due to ongoing negotiations on UAVs' access to airspace and compliance with airspace regulations and technological development needed to meet the World Meteorological Organization's requirements.

India Meteorological Department (IMD) is an Indian agency of the Ministry of Earth Sciences of the Government of India. It is the principal agency responsible for meteorological observations, weather forecasting and seismology. IMD is headquartered in Delhi and operates hundreds of observation stations across India and Antarctica. Regional offices are at Chennai, Mumbai, Kolkata, Nagpur, Guwahati and New Delhi.

IMD is also one of the six Regional Specialised Meteorological Centres of the World Meteorological Organisation. It has the responsibility for forecasting, naming and distribution of warnings for tropical cyclones in the Northern Indian Ocean region, including the Malacca Straits, the Bay of Bengal, the Arabian Sea and the Persian Gulf.

The International Meteorological Organization (IMO; 1873–1951) was the first organization formed with the purpose of exchanging weather information among the countries of the world. It came into existence from the realization that weather systems move across country boundaries; and that knowledge of pressure, temperature, precipitations, etc., upstream and downstream are needed for weather forecasting. It was superseded by the World Meteorological Organization.

In meteorology and climatology, a mesonet, portmanteau of mesoscale network, is a network of automated weather and, often also including environmental monitoring stations, designed to observe mesoscale meteorological phenomena and/or microclimates.

Dry lines, squall lines, and sea breezes are examples of phenomena observed by mesonets. Due to the space and time scales associated with mesoscale phenomena and microclimates, weather stations comprising a mesonet are spaced closer together and report more frequently than synoptic scale observing networks, such as the WMO Global Observing System (GOS) and US ASOS. The term mesonet refers to the collective group of these weather stations, which are usually owned and operated by a common entity. Mesonets generally record in situ surface weather observations but some involve other observation platforms, particularly vertical profiles of the planetary boundary layer (PBL). Other environmental parameters may include insolation and various variables of interest to particular users, such as soil temperature or road conditions (the latter notable in Road Weather Information System (RWIS) networks).

The highest temperature recorded on Earth has been measured in three major ways: air, ground, and via satellite observation. Air measurements are used as the standard measurement due to persistent issues with unreliable ground and satellite readings. Air measurements are noted by the World Meteorological Organization (WMO) and Guinness World Records among others as the standard to be used for determining the official record. The current official highest registered air temperature on Earth is 56.7 °C (134 °F), recorded on 10 July 1913 at Furnace Creek Ranch, in Death Valley, Eastern California in the United States.

For a few years, a former record that was measured in Libya had been in place, until it was decertified in 2012 based on evidence that it was an erroneous reading. This finding has since raised questions about the legitimacy of the 1913 record measured in Death Valley, with several meteorological experts asserting that there were similar irregularities. The WMO has stood by the record as official pending any future investigative results. If the current record were to be decertified then the holder would be a tie at 54.0 °C (129.2 °F), recorded at Furnace Creek (2013), Kuwait (2016) and Mandatory Palestine (1942).