The weather portal

GreatBlizzardof2006.jpg


Wall cloud with lightning - NOAA - rotated.jpg


Union City Oklahoma Tornado (mature).jpg

Photo descriptions

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...)

Refresh with new selections below (purge)

Selected article

Subtropical Storm Andrea in May 2007

A subtropical cyclone is a weather system that has some characteristics of a tropical and an extratropical cyclone. As early as the 1950s, meteorologists were unclear whether they should be characterized as tropical or extratropical cyclones. They were officially recognized by the National Hurricane Center in 1972. Subtropical cyclones began to receive names from the official tropical cyclone lists in the Atlantic Basin in 2002.

There are two definitions currently used for subtropical cyclones. Across the north Atlantic and southwest Indian ocean, they require central convection fairly near the center and a warming core in the mid-levels of the troposphere. Across the eastern half of the northern Pacific, they require a mid-tropospheric cyclone to cut off from the main belt of the westerlies and only a weak surface circulation. Subtropical cyclones have broad wind patterns with maximum sustained winds located farther from the center than typical tropical cyclones, and have no weather fronts linked into their center.

Since they form from initially extratropical cyclones which have colder temperatures aloft than normally found in the tropics, the sea surface temperatures required for their formation are lower than the tropical cyclone threshold by 3°C (5°F), lying around 23 °C (73 °F). This also means that subtropical cyclones are more likely to form outside the traditional bounds of the hurricane season.

Recently selected articles: Precipitation, Super Tuesday tornado outbreak, More...

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

Nuvola apps filetypes.svg

Selected image

Nebelostfriesland.jpg

Ground fog is a name given to fog that forms a shallow layer near the ground, sometimes just tens of centimeters thick. It can form due to warm air moving over a colder surface (advection fog), or at night due to the escape of thermal radiation into space (radiation fog). This scene is in East Frisia, Germany just after sunrise.

Recently selected pictures: Virga over London, Hurricane Isabel satellite, Hurricane Katrina Eye, 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?


Archive of previous DYK...

Recent and ongoing weather

Read and edit Wikinews

This week in weather history...

December 10

2021: A violent tornado outbreak killed 90 people in the Central United States, including 75 in Kentucky alone. The 69 tornadoes that touched down were the most ever recorded for an outbreak in the month of December, until that record was broken less than a week later.

December 11

1992: A strong nor'easter caused severe coastal flooding in the Northeastern and Mid-Atlantic United States, especially the state of New Jersey.

December 12

2012: Cyclone Evan began impacting Samoa, eventually killing 14 people across the island country.

December 13

2013: A historic snowfall struck parts of the Middle East, including the first snow recorded in Cairo in more than 100 years.

December 14

2008: Typhoon Dolphin sunk the combined cargo/passenger ship M/Bca Mae Jan, killing 47 people.

December 15

2016: The first satellite of the Cyclone Global Navigation Satellite System, a multi-satellite project using GPS signals to probe the inner workings of the atmosphere and ocean within tropical cyclones, was launched.

December 16

1964: Super Typhoon Opal, the last of a record 39 named storms in the 1964 Pacific typhoon season, dissipated near Hong Kong.

Selected biography

Portrait of Johannes Letzmann

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...)

Previously selected biographies: Ted Fujita, Sakuhei Fujiwhara, More...

Related portals

Quality content

Featured articles

Featured article star.svg


Featured lists

Featured article star.svg


Featured pictures

Featured article star.svg

Mammatus cloud panorama.jpg

Mammatus cloud

Rolling-thunder-cloud.jpg

Rolling thunder cloud

Gafilo 2004-03-06 0655Z.jpg

Cyclone Gafilo

Mammatus cloud panorama.jpg

Mammatus cloud

Farmer walking in dust storm Cimarron County Oklahoma2.jpg

Dust Bowl

More weather-related Featured Pictures...


Featured topics

Cscr-featuredtopic.svg


Featured candidates update

Cscr-candidate.svg

     Feat. article candidates:

     Featured list candidates:

     Feat. picture candidates:

     Other candidates:


Good articles

Symbol support vote.svg


Subcategories

Category puzzle
Select [►] to view subcategories

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 Wikipdia'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!

Associated Wikimedia

The following Wikimedia Foundation sister projects provide more on this subject:

Other Portals

Discover Wikipedia using portals

What you can do


Here are some tasks awaiting attention:

Purge server cache