Wiki.RIP

Portal:Weather

From Wikipedia, the free encyclopedia

The weather portal

Weather is an all-encompassing term used to describe all of the many and varied phenomena that occur in the atmosphere of a planet at a given time. The term usually refers to the activity of these phenomena over short periods of hours or days, as opposed to the term climate, which refers to the average atmospheric conditions over longer periods of time. When used without qualification, "weather" is understood to be the weather of Earth.

Weather most often results from temperature differences from one place to another, caused by the Sun heating areas near the equator more than the poles, or by different areas of the Earth absorbing varying amounts of heat, due to differences in albedo, moisture, and cloud cover. Surface temperature differences in turn cause pressure differences. A hot surface heats the air above it and the air expands, lowering the air pressure. The resulting pressure gradient accelerates the air from high to low pressure, creating wind, and Earth's rotation causes curvature of the flow via the Coriolis effect. These simple systems can interact, producing more complex systems, and thus other weather phenomena.

The strong temperature contrast between polar and tropical air gives rise to the jet stream. Most weather phenomena in the mid-latitudes are caused by instabilities of the jet stream flow (see baroclinity) or by weather fronts. Weather systems in the tropics are caused by different processes, such as monsoons or organized thunderstorm systems.

Because the Earth's axis is tilted relative to its orbital plane, sunlight is incident at different angles at different times of the year. In June the Northern Hemisphere is tilted towards the sun, while in December it is tilted away, causing yearly changes in the weather known as seasons. In the mid-latitudes, winter weather often includes snow and sleet, while in both the mid-latitudes and most of the tropics, tropical cyclones form in the summer and autumn. Almost all weather phenomena can occur year-round on different parts of the planet, including snow, rain, lightning, and, more rarely, hail and tornadoes.

Related portals: Earth sciences Featured article  · Tropical cyclones Featured article  · Water

Selected image

DustStormInSpearmanTexas19350414.jpg

This dust storm occurred around Spearman, Texas on April 14, 1935. This was in the heart of the Dust Bowl, a period of severe dust storms and drought, which contributed to the Great Depression in the United States.

Recently selected pictures: Cordell, Oklahoma tornado, Mammatus clouds, Von Kármán vortex street, More...

Selected article

A surface weather analysis is a type of weather map which provides a view of weather elements at a specified time based on information from ground-based weather stations. Weather maps are created by plotting or tracing the values of relevant quantities such as sea level pressure, temperature, and cloud cover onto a geographical map to help find synoptic scale features such as weather fronts.

The first weather maps in the 19th century were drawn well after the fact to help devise a theory on storm systems. After the advent of the telegraph, simultaneous observations of weather became possible for the first time, and beginning in the late 1840s, the Smithsonian Institution became the first organization to draw real-time surface analyses. Use of surface analyses began first in the United States, spreading worldwide during the 1870s. Use of the Norwegian cyclone model for frontal analysis began in the late 1910s across Europe, with its use finally spreading to the United States during World War II.

Surface weather analyses have special symbols which show frontal systems, cloud cover, precipitation, or other important information. For example, an H may represent high pressure, implying good and fair weather. An L on the other hand may represent low pressure, which frequently accompanies precipitation. Various symbols are used not just for frontal zones and other surface boundaries on weather maps, but also to depict the present weather at various locations on the weather map. The surface weather analysis is useful for visualizing general trends in the weather across a relatively large geographic area.

Surface analysis.gif

Recently selected articles: Snow in Florida, Great Lakes Storm, More...

Did you know...

...that a cryoseism is a sudden ground or glacier movement that can occur due to water freezing or ice cracking after drastic temperature changes?

...that BUFR is a binary data format standardized by the World Meteorological Organization for storing observation data from weather stations and weather satellites?

...that the Northwest Weather and Avalanche Center issues weather forecasts for conditions that can cause avalanches in the mountains of western Washington and northwestern Oregon?

...that a wind chill warning is issued by the National Weather Service when a combination of wind and cold temperatures is expected to cause life-threatening conditions for anyone caught outside?

...that AMeDAS, commonly known in Japan as "アメダス" (amedasu), is a network of more than 1,300 surface weather observation stations that cover Japan with an average separation between weather stations of just 17 km (11 mi)?

...that the European Severe Storms Laboratory was founded in 2006 as a research institution for studying severe weather events across Europe and the Mediterranean?

Recent and ongoing weather

Read and edit Wikinews

This week in weather history...

March 24

1994: Cyclone Nadia made landfall in Mozambique between Nacala and the Island of Mozambique. The storm directly killed more than 200 people, and also disrupted the local harvest causing starvation which would kill hundreds more.

March 25

1948: A second tornado in six days struck Tinker Air Force Base, after the first official tornado prediction ever issued.

March 26

2009: Severe flooding exceeded 40 feet at Fargo, North Dakota, breaking a record set in 1897.

March 27

1890: A deadly tornado outbreak killed more than 100 people across the central United States, including at least 76 deaths in Louisville, Kentucky.

March 28

2004: Hurricane Catarina, the only known severe tropical cyclone ever to form in the southern Atlantic Ocean, made landfall north of Torres, Brazil. More than $350 million (USD) in damage and as many as 10 deaths were caused by the storm.

March 29

1998: A supercell dropped 13 tornadoes across southern Minnesota, killing two people in the state's earliest tornado outbreak on record.

March 30

2006: Cyclone Glenda, one of the strongest tropical cyclones ever in the Australian region, made landfall near Onslow, Western Australia.

Selected biography

Portrait of John Dalton FRS

John Dalton FRS (/ˈdɔːltən/; 6 September 1766 – 27 July 1844) was an English chemist, physicist, and meteorologist. He is best known for introducing the atomic theory into chemistry, and for his research into colour blindness, sometimes referred to as Daltonism in his honour.

Previously selected biographies: Sir George Stokes, Clement Lindley Wragge, More...

Quality content

Featured article star.svg


Featured article star.svg


Featured article star.svg


Cscr-featuredtopic.svg


Cscr-candidate.svg

     Other candidates:


Symbol support vote.svg


Featured article FA A-Class article A  GA B-Class article B C-Class article C Start-Class article Start Stub-Class article Stub Featured list FL  List Current-Class article Current Future-Class article Future Wikipedia Book Book Category page Category Disambiguation page Disambig  Draft Featured media FM  File  Needed  Portal  Project Redirect page Redirect  Template  NA  ??? Total
1731371,0792678802,2651,08973238182661,774666152016811082108497201109,758
WikiProject Meteorology  articles by quality     Refresh

Subcategories

Weather: Meteorology | Atmosphere | Climate | Clouds | Cyclones | Floods | Meteorological concepts | Meteorological phenomena | Precipitation | Seasons | Severe weather and convection | Snow | Storms | Tornadoes | Tropical cyclones | Weather events | Weather lore | Weather hazards | Weather modification | Weather prediction | Weather warnings and advisories | Winds

Wikiprojects

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 weather.

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:

Wikibooks
Books

Commons
Media

Wikinews 
News

Wikiquote 
Quotations

Wikisource 
Texts

Wikiversity
Learning resources

Wiktionary 
Definitions

Wikidata 
Database


Other Portals

Purge server cache

What is Wiki.RIP There is a free information resource on the Internet. It is open to any user. Wiki is a library that is public and multilingual.

The basis of this page is on Wikipedia. Text licensed under CC BY-SA 3.0 Unported License..

Wikipedia® is a registered trademark of Wikimedia Foundation, Inc. wiki.rip is an independent company that is not affiliated with the Wikimedia Foundation (Wikimedia Foundation).

E-mail: wiki@wiki.rip
WIKI OPPORTUNITIES
Privacy Policy      Terms of Use      Disclaimer