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Portal:Weather

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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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Major damage from the tornado
Major damage from the tornado

The Evansville Tornado of November 2005 was a powerful tornado that formed early in the morning of November 6, 2005, outside of Evansville, a city in Southwestern Indiana on the Ohio River. It was the first of several significant tornado events in the month of November 2005. The tornado resulted in 25 confirmed fatalities across the region, making it by far the deadliest and most destructive tornado in the United States in 2005, and it was also the deadliest single tornado in the US since 36 died in Oklahoma on May 3, 1999. Significant tornadoes were also reported in western Kentucky on the same day, but none were as damaging or deadly as the Evansville storm.

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An atmospheric gravity wave manifests itself as altocumulus undulatus clouds in an arid environment, in the Tadrart Acacus region of southeast Algeria.

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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

This week in weather history...

August 1

1982: Typhoon Bess struck the Japanese island of Honshū, killing 59 people.

August 2

2012: Typhoon Damrey made landfall over Jiangsu in northern China, just a few hours before Typhoon Saola struck Fujian in southern part of the country. The two storms together killed more than 100 people.

August 3

2006: Typhoon Prapiroon struck southern China near Shangyang, resulting in severe flooding which caused about $1 billion (USD) in damage.

August 4

2016: Hurricane Earl moved onshore near Belize City, Belize. After landfall Earl moved westward into Mexico, where heavy rain caused landslides that killed at least 81 people.

August 5

2011: Typhoon Muifa passed through Okinawa Prefecture, Japan, bringing up to 41 inches (1,000 mm) of rain and sustained winds of 65 knots (75 mph; 120 km/h) to Okinawa Island.

August 6

2010: A flash flood killed 255 people in the Ladakh region of northern India.

August 7

1944: The 53rd Weather Reconnaissance Squadron, better known as the Hurricane Hunters, were first activated out of Presque Isle Army Air Field, Maine.

Selected biography

Anders Celsius. Portrait by Olof Arenius (1701-1766)

Anders Celsius (Swedish pronunciation: [ˈânːdɛʂ ˈsɛ̌lːsɪɵs]; 27 November 1701 – 25 April 1744) was a Swedish astronomer, physicist and mathematician. He was professor of astronomy at Uppsala University from 1730 to 1744, but traveled from 1732 to 1735 visiting notable observatories in Germany, Italy and France. He founded the Uppsala Astronomical Observatory in 1741, and in 1742 proposed (an inverted form of) the Centigrade temperature scale which was later renamed Celsius in his honour. (Full article...)

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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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