Portal:Weather
The weather portal
Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmosphere, the troposphere, just below the stratosphere. Weather refers to day-to-day temperature, precipitation, and other atmospheric conditions, whereas climate is the term for the averaging of atmospheric conditions over longer periods of time. When used without qualification, "weather" is generally understood to mean the weather of Earth.
Weather is driven by air pressure, temperature, and moisture differences between one place and another. These differences can occur due to the Sun's angle at any particular spot, which varies with latitude. The strong temperature contrast between polar and tropical air gives rise to the largest scale atmospheric circulations: the Hadley cell, the Ferrel cell, the polar cell, and the jet stream. Weather systems in the middle latitudes, such as extratropical cyclones, are caused by instabilities of the jet streamflow. Because Earth's axis is tilted relative to its orbital plane (called the ecliptic), sunlight is incident at different angles at different times of the year. On Earth's surface, temperatures usually range ±40 °C (−40 °F to 104 °F) annually. Over thousands of years, changes in Earth's orbit can affect the amount and distribution of solar energy received by Earth, thus influencing long-term climate and global climate change.
Surface temperature differences in turn cause pressure differences. Higher altitudes are cooler than lower altitudes, as most atmospheric heating is due to contact with the Earth's surface while radiative losses to space are mostly constant. Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location. Earth's weather system is a chaotic system; as a result, small changes to one part of the system can grow to have large effects on the system as a whole. Human attempts to control the weather have occurred throughout history, and there is evidence that human activities such as agriculture and industry have modified weather patterns.
Studying how the weather works on other planets has been helpful in understanding how weather works on Earth. A famous landmark in the Solar System, Jupiter's Great Red Spot, is an anticyclonic storm known to have existed for at least 300 years. However, the weather is not limited to planetary bodies. A star's corona is constantly being lost to space, creating what is essentially a very thin atmosphere throughout the Solar System. The movement of mass ejected from the Sun is known as the solar wind. (Full article...)
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Wind is the flow of gases on a large scale. On the surface of the Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the Sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space. Winds are commonly classified by their spatial scale, their speed, the types of forces that cause them, the regions in which they occur, and their effect. The strongest observed winds on a planet in the Solar System occur on Neptune and Saturn. Winds have various aspects: velocity (wind speed); the density of the gas involved; energy content or wind energy. Wind is also an important means of transportation for seeds and small birds; with time things can travel thousands of miles in the wind.
In meteorology, winds are often referred to according to their strength, and the direction from which the wind is blowing. Short bursts of high-speed wind are termed gusts. Strong winds of intermediate duration (around one minute) are termed squalls. Long-duration winds have various names associated with their average strength, such as breeze, gale, storm, and hurricane. Wind occurs on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few hours, to global winds resulting from the difference in absorption of solar energy between the climate zones on Earth. The two main causes of large-scale atmospheric circulation are the differential heating between the equator and the poles, and the rotation of the planet (Coriolis effect). Within the tropics, thermal low circulations over terrain and high plateaus can drive monsoon circulations. In coastal areas the sea breeze/land breeze cycle can define local winds; in areas that have variable terrain, mountain and valley breezes can dominate local winds.
In human civilization, the concept of wind has been explored in mythology, influenced the events of history, expanded the range of transport and warfare, and provided a power source for mechanical work, electricity, and recreation. Wind powers the voyages of sailing ships across Earth's oceans. Hot air balloons use the wind to take short trips, and powered flight uses it to increase lift and reduce fuel consumption. Areas of wind shear caused by various weather phenomena can lead to dangerous situations for aircraft. When winds become strong, trees and human-made structures are damaged or destroyed.
Winds can shape landforms, via a variety of aeolian processes such as the formation of fertile soils, such as loess, and by erosion. Dust from large deserts can be moved great distances from its source region by the prevailing winds; winds that are accelerated by rough topography and associated with dust outbreaks have been assigned regional names in various parts of the world because of their significant effects on those regions. Wind also affects the spread of wildfires. Winds can disperse seeds from various plants, enabling the survival and dispersal of those plant species, as well as flying insect populations. When combined with cold temperatures, wind has a negative impact on livestock. Wind affects animals' food stores, as well as their hunting and defensive strategies.
Previously selected articles: Atmosphere of Jupiter, Tropical Storm Allison, Tornado, More...
Did you know (auto-generated) -
- ... that the apricot dress of Jacqueline Kennedy kept its shape in India's hot weather?
- ... that after Irish post office clerk Maureen Flavin Sweeney reported worsening weather conditions, Dwight D. Eisenhower agreed to postpone D-Day by 24 hours?
- ... that a Michigan TV station rescued and restored a weather ball that had been sitting for years in a scrapyard?
- ... that weather whiplash is the phenomenon of rapid swings between extremes of weather conditions?
- ... that Japanese actor Kouhei Higuchi prepared for his role on the television drama adaptation of My Personal Weatherman by learning from a weather forecaster?
- ... that Come In was recorded on a hands-free microphone attached to a pair of headphones?
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Crepuscular rays, in atmospheric optics, are rays of sunlight that appear to radiate from a single point in the sky. These rays, which stream through gaps in clouds, are parallel columns of sunlit air separated by darker cloud-shadowed regions. The term "crepuscular" comes from their frequent occurrences during twilight, when the contrasts between light and dark are the most obvious. Various aerosols scatter the sunlight and make these rays visible. The reason we see the light so defined is because of diffraction, reflection and scattering. Crepuscular rays are near-parallel, but appear to diverge because of linear perspective. They often occur when objects such as mountain peaks or clouds partially shadow the sun's rays.
Recently selected pictures: Cumulonimbus cloud, Ice storm leaves, Mackerel sky, More...
More did you know...
...that the Flying river is the name given to the transport of water vapor from the Amazon rainforest to southern Brazil?
...that hurricane shutters are required for all homes in Florida unless impact-resistant glass is used?
...that the Joint Institute for Marine and Atmospheric Research is a combined weather and ocean research institute with the cooperation of the Office of Oceanic and Atmospheric Research and the University of Hawaiʻi?
...that the SS Central America was sunk by a hurricane while carrying more than 30,000 pounds (13,600 kg) of gold, contributing to the Panic of 1857?
...that a hurricane force wind warning is issued by the United States National Weather Service for storms that are not tropical cyclones but are expected to produce hurricane-force winds (65 knots (75 mph; 120 km/h) or higher)?
...that the Automated Tropical Cyclone Forecasting System is a software package for tropical cyclone forecasting developed in 1988 that is still used today by meteorologists in various branches of the US Government?
Recent and ongoing weather
- Wikinews weather portal
- March 26, 2021: Tropical moisture ceases to cause severe floods in South East Australia
- February 19, 2021: Winter storms hammer Texas, fatalities reported
- December 28, 2021: Typhoon Phanfone strikes Philippines
- February 1, 2022: Deadly floods in Brazil after heavy rainfall
- April 15, 2022: South African floods kill at least 300 people
- Weather of 2024
- 2024 Atlantic hurricane season
- 2020–21 North American winter
- 2024 Pacific typhoon season
- Tornadoes of 2024
This week in weather history...
December 15
1999: Intense rains in the Venezuelan state of Vargas caused extreme landslides and debris flows which continued into the next day, destroying entire towns and killing tens of thousands of people.
December 16
2011: Tropical Storm Washi made landfall on the Philippine island of Mindanao, causing flash flooding which killed over 1000 people.
December 17
1944: Typhoon Cobra struck the US Fast Carrier Task Force in the Philippine Sea, killing 790 sailors.
December 18
1959: Typhoon Gilda made landfall in the central Philippines, killing 23 people.
December 19
2001: The highest equivalent sea-level air pressure in recorded history, 1,085.6 millibars (32.06 inHg), was measured at Tosontsengel, Khövsgöl Province, Mongolia.
December 20
2006: The first of two blizzards within a 9-day period crippled the Front Range Urban Corridor of Colorado with up to 32 inches (81 cm) of snow.
December 21
2017: Typhoon Tembin passed over Mindanao, Philippines, killing 266 people.
Selected biography
Robert Allen "Bob" Case (December 16, 1939 – June 19, 2008) was a meteorologist who worked for the National Weather Service (NWS) for 28 years. Over the course of his career, he worked in NWS various offices, developing a diverse background in various types of weather forecasting, including a lengthy stint as a hurricane forecaster. He is best known for inspiring the naming of the 1991 Perfect Storm as The Perfect Storm. (Full article...)
Previously selected biographies: Wladimir Köppen, John Park Finley, More...
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- Featured Article Review: 2005 Atlantic hurricane season (Discussion)
- Featured List Removal Candidate: List of storms in the 2005 Atlantic hurricane season (Discussion)
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WikiProjects
The scope of WikiProject Weather is to have a single location for all weather-related articles on Wikipedia.
WikiProject Meteorology is a collaborative effort by dozens of Wikipedians to improve the quality of meteorology- and weather-related articles. If you would like to help, visit the project talk page, and see what needs doing.
WikiProject Severe weather is a similar project specific to articles about severe weather. Their talk page is located here.
WikiProject Tropical cyclones is a daughter project of WikiProject meteorology. The dozens of semi-active members and several full-time members focus on improving Wikipedia's coverage of tropical cyclones.
WikiProject Non-tropical storms is a collaborative project to improve articles related to winter storms, wind storms, and extratropical cyclones.
Wikipedia is a fully collaborative effort by volunteers. So if you see something you think you can improve, be bold and get to editing! We appreciate any help you can provide!
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