Blocks in meteorology are large-scale patterns in the atmospheric pressure field that are nearly stationary, effectively "blocking" or redirecting migratory cyclones . They are also known as blocking highs or blocking anticyclones . These blocks can remain in place for several days or even weeks, causing the areas affected by them to have the same kind of weather for an extended period of time (e.g. precipitation for some areas, clear skies for others). In the Northern Hemisphere , extended blocking occurs most frequently in the spring over the eastern Pacific and Atlantic Oceans. Whilst these events are linked to the occurrence of extreme weather events such as heat waves, particularly the onset and decay of these events is still not well captured in numerical weather forecasts and remains an open area of research.
41-550: For the blocking policy on Misplaced Pages, see Misplaced Pages:Blocking policy . For help with being blocked, see Help:I have been blocked and Misplaced Pages:Appealing a block [REDACTED] Look up Block , Blocks , block , blocked , or blocks in Wiktionary, the free dictionary. Block or blocked may refer to: Arts, entertainment and media [ edit ] Broadcasting [ edit ] Block programming ,
82-477: A nerve, often for the purpose of pain relief Third-degree atrioventricular block (AV block), a medical condition Mathematics [ edit ] Block (permutation group theory) Block, in modular representation theory Block, in graph theory, is a biconnected component , a maximal biconnected subgraph of a graph Aschbacher block of a finite group Block design , a kind of set system in combinatorial mathematics Block matrix Block of
123-477: A nerve, often for the purpose of pain relief Third-degree atrioventricular block (AV block), a medical condition Mathematics [ edit ] Block (permutation group theory) Block, in modular representation theory Block, in graph theory, is a biconnected component , a maximal biconnected subgraph of a graph Aschbacher block of a finite group Block design , a kind of set system in combinatorial mathematics Block matrix Block of
164-450: A puzzle game for the iPhone and iPod Touch Building and construction [ edit ] Concrete block , cinder block or cement block, a concrete masonry unit for building Compressed earth block , a building block or unit for construction Tower block , a high-rise building Land subdivisions [ edit ] Block (district subdivision) , administrative region in some South Asian countries Block (rural Australia) ,
205-431: A record label Woodblock (instrument) , a small piece of slit drum made from one piece of wood and used as a percussion instrument "Blocks", by C418 from Minecraft – Volume Beta , 2013 Toys [ edit ] Toy block , one of a set of wooden or plastic pieces, of various shapes Unit block , a type of standardized wooden toy block for children Video game [ edit ] Blocked (video game) ,
246-469: A ring , a centrally primitive idempotent or the ideal it generates Sports [ edit ] Block, a defensive shot in pickleball Block (basketball) , when a defensive player legally deflects a shot Block (cricket) , when a batsman deflects the ball to avoid getting out Blocking (American football) Blocking (martial arts) Starting blocks , devices used by sprinters to assist in preventing their feet from slipping as they break into
287-469: A ring , a centrally primitive idempotent or the ideal it generates Sports [ edit ] Block, a defensive shot in pickleball Block (basketball) , when a defensive player legally deflects a shot Block (cricket) , when a batsman deflects the ball to avoid getting out Blocking (American football) Blocking (martial arts) Starting blocks , devices used by sprinters to assist in preventing their feet from slipping as they break into
328-643: A run The Block (basketball) , a defensive play in game 7 of the 2016 NBA Finals Transportation [ edit ] Block number , a system to differentiate between groups of aircraft of the same type with minor variants Signalling block system , a way of controlling train movement People [ edit ] Main article: Block (surname) Block (musician) (Jamie Block), an anti-folk musician based in New York, US Other uses [ edit ] Block letters (also known as printscript, manuscript, print writing, or ball and stick in academics),
369-587: A run The Block (basketball) , a defensive play in game 7 of the 2016 NBA Finals Transportation [ edit ] Block number , a system to differentiate between groups of aircraft of the same type with minor variants Signalling block system , a way of controlling train movement People [ edit ] Main article: Block (surname) Block (musician) (Jamie Block), an anti-folk musician based in New York, US Other uses [ edit ] Block letters (also known as printscript, manuscript, print writing, or ball and stick in academics),
410-852: A sans-serif (or "Gothic") style of writing Block party (also known as street party), a community social event Block scheduling , a type of academic scheduling Hat block , or block shaper, a wooden block carved into the shape of a hat by a craftsman Postage stamp block , an attached group of postage stamps See also [ edit ] All pages with titles beginning with Block All pages with titles containing Block All pages with titles beginning with Blocked Block House (disambiguation) Block Party (disambiguation) The Block (disambiguation) Blockbuster (disambiguation) Blockhead (disambiguation) Bloc (disambiguation) Blockade (disambiguation) Blockbuster (disambiguation) Blocker (disambiguation) Blocking (disambiguation) Topics referred to by
451-852: A sans-serif (or "Gothic") style of writing Block party (also known as street party), a community social event Block scheduling , a type of academic scheduling Hat block , or block shaper, a wooden block carved into the shape of a hat by a craftsman Postage stamp block , an attached group of postage stamps See also [ edit ] All pages with titles beginning with Block All pages with titles containing Block All pages with titles beginning with Blocked Block House (disambiguation) Block Party (disambiguation) The Block (disambiguation) Blockbuster (disambiguation) Blockhead (disambiguation) Bloc (disambiguation) Blockade (disambiguation) Blockbuster (disambiguation) Blocker (disambiguation) Blocking (disambiguation) Topics referred to by
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#1732765406610492-577: A set of adjacent groups in the periodic table Block (meteorology) , large-scale patterns in the atmospheric pressure field Fault block , a geologic zone or geologic province Block, Inc. , an American technology company formerly known as Square Computing [ edit ] Blockchain , a segment of an open list of data records Block (data storage) , the practice of storing electronic data in equally sized units Block (Internet) , technical measures to restrict users' access to certain internet resources Blocking access to certain websites
533-577: A set of adjacent groups in the periodic table Block (meteorology) , large-scale patterns in the atmospheric pressure field Fault block , a geologic zone or geologic province Block, Inc. , an American technology company formerly known as Square Computing [ edit ] Blockchain , a segment of an open list of data records Block (data storage) , the practice of storing electronic data in equally sized units Block (Internet) , technical measures to restrict users' access to certain internet resources Blocking access to certain websites
574-446: A small agricultural landholding City block , the smallest area that is surrounded by streets Places [ edit ] United States [ edit ] Block, Illinois , an unincorporated community Block, Kansas , an unincorporated community Block, Tennessee , an unincorporated community Block Island , an island in the state of Rhode Island Science and technology [ edit ] Block (periodic table) ,
615-446: A small agricultural landholding City block , the smallest area that is surrounded by streets Places [ edit ] United States [ edit ] Block, Illinois , an unincorporated community Block, Kansas , an unincorporated community Block, Tennessee , an unincorporated community Block Island , an island in the state of Rhode Island Science and technology [ edit ] Block (periodic table) ,
656-519: A tendency to produce anomalously mild conditions at very high latitudes, at least in those regions exposed to anomalous flow from the ocean as in Greenland and Beringia , or from chinook winds as in Interior Alaska . Such cold winters over the contiguous United States and southern Canada as 1911/12 , 1935/36 , 1949/50, 1977/78 and 1978/79, 1993/94, and 2017/18 resulted from blocks in
697-565: A type of standardized wooden toy block for children Video game [ edit ] Blocked (video game) , a puzzle game for the iPhone and iPod Touch Building and construction [ edit ] Concrete block , cinder block or cement block, a concrete masonry unit for building Compressed earth block , a building block or unit for construction Tower block , a high-rise building Land subdivisions [ edit ] Block (district subdivision) , administrative region in some South Asian countries Block (rural Australia) ,
738-434: Is different from Wikidata All article disambiguation pages All disambiguation pages Block For the blocking policy on Misplaced Pages, see Misplaced Pages:Blocking policy . For help with being blocked, see Help:I have been blocked and Misplaced Pages:Appealing a block [REDACTED] Look up Block , Blocks , block , blocked , or blocks in Wiktionary,
779-630: Is different from Wikidata All article disambiguation pages All disambiguation pages Block (meteorology) Polar cyclones are climatological features which hover near the poles year-round. They are weaker during summer and strongest during winter. When the polar vortex is strong, the Westerlies increase in strength. When the polar cyclone is weak, the general flow pattern across mid-latitudes buckles and significant cold outbreaks occur. Extratropical cyclones which occlude and migrate into higher latitudes create cold-core lows within
820-558: Is one form of internet censorship Block or subnet of the Internet, a subset of the internet in a set of contiguous IP addresses Block (programming) , a group of declarations and statements treated as a unit Block (telecommunications) , a unit of data transmission Block artifact , a type of distortion in a compressed image Block-level element , in the HTML markup language Blocks (C language extension) , an extension to
861-451: Is one form of internet censorship Block or subnet of the Internet, a subset of the internet in a set of contiguous IP addresses Block (programming) , a group of declarations and statements treated as a unit Block (telecommunications) , a unit of data transmission Block artifact , a type of distortion in a compressed image Block-level element , in the HTML markup language Blocks (C language extension) , an extension to
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#1732765406610902-692: The Gulf of Alaska or to the east of the Mackenzie Mountains directing very cold Arctic air with a long trajectory as far as the American South , as did the Western cold waves of 1889/90 and January 1950. In Northern and Western Europe , cold winters such as 1683/84, 1739/40, 1794/95, 1829/30, 1894/95 , 1916/17, 1941/42, February 1947 and 1962/63 are almost always associated with high latitude Atlantic blocking and an equatorward shift of
943-591: The C programming language designed to support parallel programming Unicode block , a named range of codepoints in Unicode Block Elements , a Unicode block of block-shaped characters Engineering [ edit ] Engine block and cylinder block, the main part of an internal combustion engine Block (sailing) , a single or multiple pulley used on sailboats Medicine [ edit ] Nerve block , or regional nerve blockade, any deliberate interruption of signals traveling along
984-516: The C programming language designed to support parallel programming Unicode block , a named range of codepoints in Unicode Block Elements , a Unicode block of block-shaped characters Engineering [ edit ] Engine block and cylinder block, the main part of an internal combustion engine Block (sailing) , a single or multiple pulley used on sailboats Medicine [ edit ] Nerve block , or regional nerve blockade, any deliberate interruption of signals traveling along
1025-572: The Northern Hemisphere resemble an Ω, the uppercase Greek letter omega . They typically have a low-high-low pattern, arranged in the west–east direction. Rex blocks (or dipole blocks) consist of a high situated poleward (north in the Northern Hemisphere; south in the Southern Hemisphere) of a low. Very often both the high and the low are closed, meaning that the isobars (or constant geopotential height lines) defining
1066-475: The Northern Hemisphere, however, cold winters in Europe (e.g. 1916/17, 1962/63) are often very mild over Central Asia, which can gain warm air advection from subtropical cyclones pushed to the south under negative NAO conditions. Heat waves in summer are the result of similar blocking patterns, typically involving the placement of the semi-permanent subtropical ridge . Some unusually intense summers such as 1936 in
1107-545: The United States, 1999, 2002, and 2011, and in Europe summers such as 1976, 2003 European heat wave , and 2019, were the result of entrenched highs that became detached from the jet stream for a prolonged period of time and allowed warm, dry air to build in place. In many cases such as the 1999 US drought, the heat wave was preceded by prior months of below normal precipitation that prevented temperatures from cooling. The 2003 heat wave in Europe occurred, conversely, during
1148-573: The block is a high, it will usually lead to dry, warm weather as the air beneath it is compressed and warmed, as happened in southeastern Australia in 2006 and 1967 with resultant extreme droughts . However, when a blocking high is situated in the Tasman Sea it can cause torrential rains in eastern Australia, as in the cases of the 2021 and 2022 flood events . A blocking high in the southern Tasman Sea directs low pressure systems and troughs towards eastern Australia, whereby providing rainfall on
1189-609: The coast of Georgia that caused a drought in the Southeast that same year. Rainy, cooler weather results if the block is a low in the US. Hurricane Ian in the last week of September 2022 drifted northward and its remnants became detached from the jet stream, resulting in a stationary low pressure system spinning off the Northeastern US and bringing several days of precipitation until a front finally moved through on October 6. If
1230-504: The east coast of Australia. In Australia, blocking highs generally occur in the Great Australian Bight and the Tasman Sea , which are powerful high-pressure systems that usually develop further south than normal. They stay virtually unmoving for a lengthy period (i.e. several days to weeks) and thus block the regular easterly motion of weather systems across southern Australia. Blocking of atmospheric systems near
1271-539: The free dictionary. Block or blocked may refer to: Arts, entertainment and media [ edit ] Broadcasting [ edit ] Block programming , the result of a programming strategy in broadcasting W242BX , a radio station licensed to Greenville, South Carolina, United States known as 96.3 the Block WFNZ-FM , a radio station licensed to Harrisburg, North Carolina, United States, branded as 92.7 The Block "Blocked", an episode of
Block - Misplaced Pages Continue
1312-412: The high–low close to form a circle. Rex blocks are named after meteorologist Daniel F. Rex, who first identified them in 1950. When an upper-level high - or low -pressure system becomes stuck in place due to a lack of steering currents , it is known as being "cut off". The usual pattern which leads to this is the jet stream retreating poleward, leaving the then cut-off system behind. Whether or not
1353-635: The polar jet stream to Portugal and even Morocco . Over Central Asia , unusually cold winters like 1899/1900, 1929/30 and 1930/31, 1944/45, 1954/55 and 1968/69 are associated with blocking near the Ural Mountains extending the Siberian High westwards to push the very cold air from the Siberian " cold pole " outward towards the Aral and Caspian Seas . Unlike other midlatitude regions of
1394-527: The polar vortex. Volcanic eruptions in the tropics lead to a stronger polar vortex during the winter for as long as two years afterwards. The strength and position of the cyclone shapes the flow pattern across the hemisphere of its influence. An index which is used in the northern hemisphere to gauge its magnitude is the Arctic oscillation . Omega blocks are so-named because the isobars or geopotential height contours with which they are associated in
1435-438: The result of a programming strategy in broadcasting W242BX , a radio station licensed to Greenville, South Carolina, United States known as 96.3 the Block WFNZ-FM , a radio station licensed to Harrisburg, North Carolina, United States, branded as 92.7 The Block "Blocked", an episode of the television series The Flash Music [ edit ] Block Entertainment , a record label Blocks Recording Club ,
1476-461: The same term [REDACTED] This disambiguation page lists articles associated with the title Block . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Block&oldid=1239380065 " Categories : Disambiguation pages Disambiguation pages with surname-holder lists Hidden categories: Short description
1517-461: The same term [REDACTED] This disambiguation page lists articles associated with the title Block . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Block&oldid=1239380065 " Categories : Disambiguation pages Disambiguation pages with surname-holder lists Hidden categories: Short description
1558-489: The stable air mass of a cold air dam. In the middle latitudes of the Northern Hemisphere, areas on the eastern side of blocking anticyclones or under the influence of anomalous flows from colder continental interiors related to blocks experience severe winters, a phenomenon which has been known since the discovery of the North Atlantic Oscillation (NAO) in the 1840s. These blocking patterns also have
1599-604: The surface of the Earth occurs when a well-established poleward high pressure system lies near or within the path of the advancing storm system. The thicker the cold air mass is, the more effectively it can block an invading milder air mass. The depth of the cold air mass is normally shallower than the mountain barrier which created the cold air damming, or CAD. Some events across the Intermountain West can last for ten days. Pollutants and smoke can remain suspended within
1640-410: The system is of high- or low-pressure variety dictates the weather that the block causes. Precisely this situation occurred over the southern United States during late spring and early summer of 2007, when a cut-off-low system hovering over the region brought unusually cool temperatures and an extraordinary amount of rain to Texas and Oklahoma (see June 2007 Texas flooding ), and a cut-off-high near
1681-451: The television series The Flash Music [ edit ] Block Entertainment , a record label Blocks Recording Club , a record label Woodblock (instrument) , a small piece of slit drum made from one piece of wood and used as a percussion instrument "Blocks", by C418 from Minecraft – Volume Beta , 2013 Toys [ edit ] Toy block , one of a set of wooden or plastic pieces, of various shapes Unit block ,