weather
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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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Recently selected articles: Weather, Cyclogenesis, More...
Did you know (auto-generated) -
- ... 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 the weather forecast for HD 189733 b is "Westerly winds at 2000 m/s, with molten glass showers"?
- ... that Eric Berger wrote about weather for the Houston Chronicle even before he became a certified meteorologist?
- ... 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 in the 1980s, "Sherman Bonner, The Human Thermometer" presented the weather on an Arkansas TV station?
- ... that weather whiplash is the phenomenon of rapid swings between extremes of weather conditions?
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Flakes of snow highly magnified by a low-temperature scanning electron microscope (SEM). The colors are called "pseudo colors"; they are computer generated and are a standard technique used with SEM images.
Recently selected pictures: Sun dog,Pyrocumulus clouds, Cloud-to-cloud lightning, 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...
April 22: Earth Day
2011: A nighttime tornado, caused major damage in parts of St. Louis, Missouri, including Lambert-St. Louis International Airport, but amazingly caused no deaths and few injuries.
April 23
1792: John Thomas Romney Robinson, inventor of the cup-anemometer, was born in Dublin, Ireland.
April 24
1908: One of the deadliest tornadoes in US history killed at least 143 people in Louisiana and Mississippi.
April 25
1994: An F4 tornado killed three people on the first day of a 3-day tornado outbreak.
April 26
1998: Cyclone Alan which had been impacting French Polynesia with several days of strong winds and heavy rain that killed 10 people, dissipated west of Tahiti.
April 27
2011: The deadliest American tornado outbreak in 76 years killed more than 300 people in the Southern United States.
April 28
2002: As part of a larger tornado outbreak, a violent tornado struck the town of La Plata, Maryland, killing 4 and injuring more than 100 people. Initially rated F5 on the Fujita scale, which would have been the strongest tornado on record in the Eastern United States, the tornado's rating was later revised downward to F4.
Selected biography
Sakuhei Fujiwhara (藤原 咲平, Fujiwara Sakuhei, October 29, 1884 – September 22, 1950) was a Japanese meteorologist who became the namesake for the Fujiwhara effect. Novelist Jirō Nitta is his nephew and mathematician Masahiko Fujiwara is his grandnephew. (Full article...)
Recently selected biographies: William Ferrel, John Dalton, More...
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- 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 Wiki English.
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.
Wiki 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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