Portal: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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The 2008 Super Tuesday tornado outbreak was a deadly tornado outbreak which affected the Southern United States and the lower Ohio Valley on February 5–6, 2008. In total, 87 tornadoes were confirmed in the outbreak's 15 hour span. Several destructive tornadoes struck heavily populated areas, most notably in the Memphis metropolitan area, in Jackson, Tennessee, and the northeastern end of the Nashville metropolitan area. Fifty-seven people were killed in the outbreak by tornadoes across four states and 18 counties, with hundreds injured and property damage totaling more than $500 million (USD).

The outbreak was the deadliest in the U.S. since the May 31, 1985 outbreak that killed 76 across Ohio and Pennsylvania (and also killed 12 in Ontario, Canada). It also was the deadliest tornado outbreak in both Tennessee and Kentucky since the 1974 Super Outbreak. In addition to the tornadoes, the same system produced significant straight-line wind damage, hail as large as softballs, or 4.50 inches (11 cm) in diameter, major flooding, significant freezing rain, and heavy snow across many areas of eastern North America.

Map of deadly tornadoes (in red) and other severe weather reports.

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Did you know (auto-generated) - show different entries

... 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 state representative Karl Bohnak, referring to his former profession, said that the Upper Peninsula of Michigan was one of the most challenging places in the U.S. to forecast the weather?
... that the apricot dress of Jacqueline Kennedy kept its shape in India's hot weather?
... that an attempted British-Norwegian attack on the German battleship Tirpitz was abandoned after two Chariot manned torpedoes were lost due to bad weather?
... 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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An animation of changing snow cover across the Earth over the period of a year. Snow cover is much more abundant in the Northern Hemisphere, which is not surprising considering that the large majority of land in the colder latitudes is in the Northern Hemisphere. Antarctica is perennially covered by snow or ice cap, except for a few places in the Antarctic Peninsula and the McMurdo Dry Valleys.

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...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?

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Recent and ongoing weather

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This week in weather history...

February 10

1994: Cyclone Hollanda struck the island nation of Mauritius in the Indian Ocean, causing major damage and killing two people.

February 11

1895: The lowest temperature in the United Kingdom, -27.2°C (-16.7°F), was measured at Braemar, Grampian, Scotland.

February 12

2006: New York City experienced its largest snowfall on record, 26.4 inches (67.1 cm).

February 13

1899: In the wake of a major blizzard that affected much of the eastern United States, hundreds of cities across the country, including Dallas, New Orleans, and Atlanta, set record low temperatures that still stand today. Several U.S. state records were set as well, in Nebraska, Ohio, Texas, and most notably Florida, where Tallahassee sank to −2 °F (−19 °C); the only time on record the state has seen temperatures below zero Fahrenheit.

February 14

2007: The Valentine's Day Storm hit its peak over the eastern half of North America. Up to 48 inches (120 cm) of snow fell in Vermont and 37 people were killed. The storm system also spawned a small tornado outbreak, killing one person near New Orleans.

February 15

1967: The TIROS-9 weather satellite ended its mission. The satellite was the first of the TIROS program to be in a near-polar orbit, allowing cloud cover pictures and radiometric temperature observations to cover the entire surface of the earth over the course of several orbits.

February 16

2005: Cyclone Olaf struck areas of American Samoa, causing severe damage.

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Christophorus Henricus Diedericus Buys Ballot (Dutch pronunciation: [ˈbœyz bɑˈlɔt]; October 10, 1817 – February 3, 1890) was a Dutch chemist and meteorologist after whom Buys Ballot's law and the Buys Ballot table are named. He was first chairman of the International Meteorological Organization, the organization that would become the World Meteorological Organization. (Full article...)

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Hurricane Katrina's eye

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Tropical Storm Ileana (2018) (Discussion)

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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!