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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A jet stream is a fast flowing, relatively narrow air current found at the tropopause, the transition between the troposphere (where temperature decreases with height) and the stratosphere (where temperature increases with height). Jet streams are typically located at 10-15 kilometers above the surface of the Earth. They form near boundaries of adjacent air masses with significant differences in temperature, such as the polar region and the warmer air to the south. The path of the jet typically has a meandering shape, and these meanders known as Rossby waves. Rossby waves propagate westward with respect to the flow in which they are embedded, which translates to a slower eastward migration across the globe than smaller scale short wave troughs. The major jet streams are westerly winds (flowing west to east) in the Northern Hemisphere.
During the summer, low-level easterly jets can form in tropical regions. A southerly low level jet in the Great Plains of North America helps fuel overnight thunderstorm activity, normally in the form of mesoscale convective systems. A similar northerly low-level jet can form across Australia, instigated by cut-off lows which develop across southwest portions of the country.
Meteorologists use the location of the jet stream as an aid in weather forecasting. The main commercial use of the jet stream is during airline travel, as flying long distances along the jet stream can cut hours off a long distance trip. One type of clear-air turbulence is found in the jet stream's vicinity, which can be a hazard to aircraft. One future benefit of the jet stream could be to augment power generation within the next 10 to 20 years, if technological hurdles can be overcome.
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Did you know (auto-generated) -
- ... 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 an attempted British-Norwegian attack on the German battleship Tirpitz was abandoned after two Chariot manned torpedoes were lost due to bad weather?
- ... that weather whiplash is the phenomenon of rapid swings between extremes of weather conditions?
- ... that the weather forecast for HD 189733 b is "Westerly winds at 2000 m/s, with molten glass showers"?
- ... that in the 1980s, "Sherman Bonner, The Human Thermometer" presented the weather on an Arkansas TV station?
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Parallax is the phenomenon of the change in the apparent position of an object when viewed from different angles. It is demonstrated nicely in this foggy scene, where the reflection of the moon appears in a different position with respect to the street lamp when viewed in the reflection in the water.
Recently selected pictures: Global snow cover, Snow flakes, Sun dogs, 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...
June 1: Start of the Central Pacific and Atlantic hurricane seasons
1999: American Airlines Flight 1420 overran the runway in a severe thunderstorm, killing 10 passengers and the pilot.
June 2
1998: An outbreak of 47 tornadoes struck the Eastern United States. Two people were killed in Wyoming County, Pennsylvania.
June 3
2010: Cyclone Phet made landfall near Al Ashkharah, Oman, causing major flooding in the desert nation.
June 4
1958: A tornado outbreak killed 28 people in Wisconsin, including 21 deaths from a single F5 tornado.
June 5
1972: The United Nations Conference on the Human Environment began in Stockholm, Sweden.
June 6
1973: Hurricane Ava became the earliest Category 5 hurricane on record in the Pacific Ocean.
June 7
1997: Cyclone Keli formed in the South Pacific Ocean, the first tropical cyclone ever recorded in the month of June in that region.
Selected biography
Johannes Peter Letzmann (19 July 1885 – 21 May 1971) was an Estonian meteorologist, and a pioneering tornado researcher. His prolific output related to severe storms concepts included: developing tornado damage studies, atmospheric vortices, theoretical studies and laboratory simulations, tornado case studies, and observation programs. It generated extensive analysis techniques and insights on tornadoes at a time when there was still very little research on the subject in the United States. (Full article...)
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Related portals
Quality content
Other candidates:
- 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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