Portal:Weather

The weather portal

Weather refers to the state of the Earth's atmosphere at a specific place and time, typically described in terms of temperature, humidity, cloud cover, and stability. 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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In meteorology, precipitation is a term for any product of the condensation of atmospheric water vapour that is deposited on the Earth's surface. It occurs when the atmosphere, becomes saturated with water vapour and the water condenses, falling out of solution. Two processes, possibly acting together, can lead to air becoming saturated: cooling the air or adding water vapour to the air. Precipitation forms via collision with other rain drops or ice crystals within a cloud.

Precipitation that reaches the surface of the earth can occur in many different forms, including rain, freezing rain, drizzle, ice needles, snow, ice pellets or sleet, graupel and hail. While snow and ice pellets require temperatures to be near or below freezing at the surface, hail can occur during much warmer temperature regimes due to the process of its formation. Precipitation also occurs on other celestial bodies—including snow on Mars and a sulfuric acid rain on Venus—though both of these evaporate before reaching the surface.

Moisture overriding associated with weather fronts is a major method of precipitation production. If enough moisture and upward motion is present, precipitation falls from convective clouds such as cumulonimbus and can organize into narrow rainbands. Precipitation can also form due to forced ascent up the windward side of a mountain or mountain range. Precipitation is a major component of the water cycle, and is responsible for depositing essentially all of the fresh water on the planet. Approximately 505,000 km³ (121,000 cu mi) of water falls as precipitation each year; 398,000 km³ (95,000 cu mi) of it over the oceans.

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... that in the 1980s, "Sherman Bonner, The Human Thermometer" presented the weather on an Arkansas TV station?
... 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 Quad Cities forecast office of the National Weather Service has been directly struck by both an F1 tornado and a historic derecho?
... that MyRadar uses a custom satellite constellation to help forecast the weather?
... that actress Jennifer Brooke and her colleagues faced severe weather from Storm Imogen while filming her death scene for Hollyoaks?
... 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?

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Lightning striking the Eiffel Tower on the night of June 3, 1902. This is one of the earliest photographs of lightning in an urban setting.

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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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This week in weather history...

December 3

1838: Cleveland Abbe, pioneering weather forecaster and founder of the academic journal Monthly Weather Review, was born in New York City.

December 4

2012: Typhoon Bopha, the strongest tropical cyclone on record to strike the island of Mindanao, Philippines, made landfall near Baganga. The storm hit with maximum sustained winds of 175 mph (280 km/h), and killed at least 1,900 people.

December 5

1952: The Great Smog descended on London, eventually leading to around 12,000 deaths from respiratory infections.

December 6

2003: Tropical Storm Odette, an unusual December tropical cyclone in the northern Atlantic Ocean, made landfall in Jaragua National Park, Dominican Republic. Eight people were killed due to flooding.

December 7

1975: Cyclone Joan made landfall near Mundabullangana, Western Australia, destroying more than 1,000 homes in Port Hedland.

December 8

1963: Pan Am Flight 214 was struck by lightning while in a holding pattern waiting to land in Philadelphia. The plane crashed near Elkton, Maryland, killing everyone aboard.

December 9

2003: Tropical Storm Peter, which had been a subtropical storm, became fully tropical. With the formation of Tropical Storm Odette five days earlier, this marked the first time that two tropical cyclones formed in December since 1887.

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Vice-Admiral Robert FitzRoy FRS (5 July 1805 – 30 April 1865) was an English officer of the Royal Navy, politician and scientist who served as the second governor of New Zealand between 1843 and 1845.

He achieved lasting fame as the captain of HMS Beagle during FitzRoy's famous survey expedition to Tierra del Fuego and the Southern Cone, which took Charles Darwin round the world.

FitzRoy was a pioneering meteorologist who made accurate daily weather predictions, which he called by a new name of his own invention: "forecasts". In 1854 he established what would later be called the Met Office, and created systems to get weather information to sailors and fishermen for their safety.

He was an able surveyor and hydrographer.

As Governor of New Zealand, serving from 1843 to 1845, he tried to protect the Māori from illegal land sales claimed by British settlers. (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!