document_title: Trucking industry in the United States

question_text: the largest motor carrier in the united states based on revenue is

text: Trucking industry in the United States

text: History[edit]

text: The trucking industry[1] has affected the political and economic history of the United States in the 20th century. Before the invention of automobiles, most freight was moved by train or horse-drawn vehicle.

text: Trucks were first used extensively by the military during World War I. With the increase in construction of paved roads, trucking began to achieve a significant foothold in the 1930s. Public safety concerns made it necessary to implement various government regulations (such as the 1965 hours of service rule; recently revised with a compliance date of July 1, 2012) of how long drivers were allowed to work and drive each day/week. In 1956, Taxpayers provided funds to build the Interstate Highway System, an extensive network of highways and freeways that linked major cities across the continent.[2] The addition of Interstate Highway System also made it possible for the trucking industry to grow substantially in the late 1950s and early 1960s and trucking has come to dominate the freight industry in the latter portion of the 20th century.

text: Trucking achieved national attention during the 1960s and 70s, when songs and movies about truck driving were major hits. Truck drivers participated in widespread strikes against the rising cost of fuel, during the energy crises of 1973 and 1979. Congress deregulated the trucking industry with the passage of the Motor Carrier Act of 1980.[3]

text: Advances in modern technology have enabled significant improvements within the trucking industry. Trucks are commonly equipped with satellite communication features, automatic transmissions are gaining in popularity, and truck stops featuring WiFi Internet access are now commonplace.[4]

text: Exhaust emissions[edit]

text: Components of diesel exhaust were confirmed as an animal carcinogen in 1988 by the National Institute for Occupational Safety and Health, and by 2002, the U.S. Environmental Protection Agency (EPA) considered it "likely to be carcinogenic to humans".[5] The particulate matter of diesel exhaust has been linked to (among other health effects) lung cancer, chronic bronchitis, and aggravated asthma; it has also been identified as a greenhouse gas. "[6] For these and other reasons, alternatives and improvements to standard diesel fuel have been developed.

text: Biodiesel (in its pure form) is a non-toxic, biodegradable form of diesel fuel made from vegetable oil, usually soybean oil or recycled restaurant grease. Biodiesel promises a reduction in some exhaust emissions,[7] as well as reduced dependence on foreign petroleum supplies.[8]

text: Starting in June 2006, petroleum refiners were required by the EPA to begin producing ultra-low sulfur diesel (ULSD) fuel, which has 97% less sulfur than the previous low sulfur diesel fuel.[9] When fuel containing sulfur is burned, sulfur dioxide is produced, a main component of acid rain.[10] ULSD, together with new air pollution control technologies required in trucks (starting with model year 2007), will reduce harmful emissions by 90%.[9]

text: By the time the action is fully implemented, the EPA estimates that 2.6 million tons of smog-causing nitrogen oxide emissions will be eliminated each year. Soot or particulate matter will be reduced by an estimated 110,000 tons a year. The reduction in sulfur will also prevent an estimated 8,300 premature deaths, 5,500 cases of chronic bronchitis and 17,600 cases of acute bronchitis in children. In addition, an estimated 360,000 asthma attacks and 386,000 cases of respiratory symptoms in asthmatic children will also be avoided every year.[11]

text: When not driving, truck drivers need to idle their engines to maintain climate control within the truck cab (interior), as well as provide electricity for appliances. Engine idling is inefficient and only adds to the problem of air pollution.[12] This unnecessary idling can be remedied with shore power (which is a term and idea borrowed from the shipping industry), or Truck Stop Electrification.[13] When ships are docked in a port, they connect to a land-based power supply to provide electricity and eliminate the need to idle their engines. The idea of shore power was transferred to the trucking industry, and now there are companies such as IdleAire[14] and Shorepower[15] which provide electricity to diesel trucks, which eliminates the need for the driver to idle the engine. IdleAire also provides access to the Internet, cable television, and land line phone services. IdleAire promises to eliminate one-eighth of nitrogen oxide pollution through "electrified parking", however, particulate pollution may increase in those areas where the electricity is provided by coal burning power plants.[16] Some drivers are also experimenting with hydrogen fuel cells, which provide clean and silent power for appliances when trucks are not running.

text: Fuel efficiency[edit]

text: With the fuel price increases of the 2000s, the EPA and many companies have sought to increase diesel truck fuel economy. One such example is the hydraulic hybrid vehicle, which stores energy in hydraulic tanks and hydraulic motors (as opposed to the electric hybrid vehicle which uses batteries and regenerative brakes).[17] Electric hybrid vehicles are another option, with savings of 35 to 60 percent over traditional vehicles.[18] Drivers themselves may improve fuel efficiency by using a method called progressive shifting, in which the driver shifts through the gears (typical trucks may have between 10 and 18 gears) in such a manner as to optimize the power range of the engine.

text: Fuel consumption[edit]

text: According to research from a survey conducted by students from the University of Michigan, and in cooperation by ATRI (American Transportation Research Institute) as of 2015 "54 billion gallons of fuel were consumed by trucks for business purposes—39 billion gallons of diesel fuel and 16 billion gallons of gasoline. Combination vehicles, which are powered nearly exclusively by diesel fuel, accounted for 75 percent of this diesel fuel consumption" [19]

text: Technology[edit]

text: Like many other industries, the trucking industry has benefited from the use of computers and the Internet. The Internet helps firms explore new opportunities by aggressive sales and marketing. The incremental cost of conducting business transactions on the Internet is as little as one-fifteenth as expensive as paper transactions.[20]

text: Given the limitations on truck weight and size, increased productivity in the industry comes from two sources: fewer empty miles and less time waiting between loads.[20] U.S. Department of Transportation figures indicate that empty routes have continued to account for 29% of single-unit truck traffic;[21][22] this has been equated to an annualized 15 billion gallons of gasoline, $30 billion cost, or 149 million tons of excess carbon emissions.[23][24] Traditional freight brokers acted as intermediaries to manage the coordination of freight, helping independent drivers or companies match loads with available empty trucks. Increasingly, computerized brokers are threatening the future of traditional human brokers by offering increased efficiency. In addition, shipper-driven brokerage over the Internet enables shippers to post loads and solicit bids directly from carriers. Instead of relying upon traditional freight brokers, shippers function as their own brokers, dealing directly with freight companies.[20]

text: Developments in satellite technology have fostered increased communication and productivity within the trucking industry.[25] Drivers may input the information from a bill of lading into a simple text-only dot matrix display screen (commonly called a "Qualcomm", for their ubiquitous OmniTRACS system).[26][27] This allows the driver to communicate with their dispatcher, who is normally responsible for determining and informing the driver of their pick-up and drop-off locations. Drivers are no longer required to find the nearest public phone in order to relay information regarding their load status, it can be done without leaving the truck cab.[25]

text: The driver inputs the information, using a keyboard, into an automated system of pre-formatted messages known as macros. There are macros for each stage of the loading and unloading process, such as "loaded and leaving shipper" and "arrived at final destination". This system also allows the company to track the driver's fuel usage, speed, gear optimization, engine idle time, location, direction of travel, and amount of time spent driving.[25]

text: Trucks equipped with GPS satellite navigation units have enabled drivers to forgo a traditional paper-based map, saving time and effort.[4] Drivers willing to pay for satellite radio or who work for a company that pays for it[28] can listen to commercial-free music, sports, news, and talk radio coast-to-coast without interruption of signals between cities (as terrestrial radio signals are limited to a certain radius from the broadcasting tower). Digital satellite television allows smaller dish sizes, which means truck drivers are not limited to free terrestrial broadcast television and have more options about what they watch during their off-duty periods.[29]

text: Automatic transmissions[edit]

text: Increasingly, companies have been equipping their trucks with automatic transmissions for a variety of reasons. Operating a manual transmission requires more skill and attention on the part of the driver, partly due to the unsynchronized transmission found in heavy-duty trucks. Companies have found that switching from manual to automatic transmissions has many benefits, including increased fuel efficiency, increased driver retention, reduced wear and tear on the internal gears of transmissions (inexperienced drivers may frequently grind the gears if proper shifting techniques are not followed), reduced driver fatigue, and reduced accidents (manuals require more attention from the driver, thus increasing the chances for an accident). All of these factors together add up to benefit the company by reducing costs incurred from transmission repairs, accidents, and driver turnover (a driver frustrated by a manual transmission may decide to quit his/her job).[30]

text: Top US trucking firms[edit]

text: As of May 2015, over 90.0% of players in the United States long-distance freight trucking industry are owner-operators. Therefore, even the top corporate operators only hold a small share of the total market. According to the industry market research firm IBISWorld, J.B. Hunt Transport Services holds an estimated 2.5% market share, YRC Worldwide holds 1.8%, FedEx holds 1.6%, United Parcel Service of America owns 1.5%, and Con-way holds 1.4%.[31]

text: In 2005, the Logistics Management ranked the top 10 US trucking firms (by net revenue) as:[32]

text: (Industry overview, ranking TL and LTL trucking firms together.)

text: Top 10 trucking companies by revenue in 2015.[33]

text:
Parent company
Primary
service
Public/
Private
Revenue (millions)
(2015)
Image

UPS Freight
Parcel
Public
$29,829

FedEx Freight
Parcel
Public
$19,827

J.B. Hunt
FCL
Public
$6,188

YRC Worldwide
LTL
Public
$4,832

Swift Transportation
FCL & FTL
Public
$4,229

Hub Group
FCL
Public
$3,526

Schneider National
FCL & FTL
Private
$3,423

Landstar System
FTL
Public
$3,364

XPO Logistics
FCL & LTL
Public
$3,273

Old Dominion Freight Line
LTL
Public
$2,788

text: Economic impact[edit]

text: The importance of trucking is communicated by the industry adage: "If you bought it, a truck brought it."[4][34] Retail stores, hospitals, gas stations, garbage disposal, construction sites, banks, and even a clean water supply depends entirely upon trucks to distribute vital cargo.[35] Even before a product reaches store shelves, the raw materials and other stages of production materials that go into manufacturing any given product are moved by trucks.[20]

text:
Commercial Freight Activity in the US by Mode of Transportation

Transportation mode
Estimates in millions
Relative shares in percents

Value
Tons
Value
Tons

Truck
$9,075,000
11,712
69.5
60.1

Rail
$392,000
1,979
3.0
10.2

Water
$673,000
1,668
5.2
8.6

Pipeline
$896,000
3,529
6.9
18.1

Other modes (incl. air, intermodal)
$2,015,000
600
15.4
3.0

Total
$13,052,000
19,847
100.0
100.0

Source: 2002 estimate by the Bureau of Transportation Statistics[36]
Note: Weights listed are measured in short tons.

text: Today, railroads are primarily used to haul bulk quantities of cargo over long distances.[37] Unless a manufacturing or distribution facility has a direct connection to the railroad, the remainder of the trip must be handled by truck.[4] Recent implementation of "just in time" strategies have resulted in the increased use of trucks to help satisfy businesses' fluid inventory needs. Using this strategy, businesses gain the ability to reduce the costs associated with excess inventory and larger warehousing facilities by requiring more frequent deliveries.[38][39][40] According to an industry group, many retail, commercial, and government services require daily or weekly deliveries to keep supplies or merchandise on hand. Many hospitals have also moved to "just in time" inventory systems. The nation's busiest gas stations require deliveries of fuel several times per day, while the average station receives fuel every two to three days. Grocery stores require deliveries of perishable food items every two to three days.[35]

text: Trucks are vitally important to U.S. industry, however, measuring the impact of trucking on the economy is more difficult, because trucking services are so intertwined with all sectors of the economy. According to the measurable share of the economy that trucking represents, the industry directly contributes about 5 percent to the gross domestic product annually. In addition, the industry plays a critical support role for other transportation modes and for other sectors of the economy such as the resource, manufacturing, construction, and wholesale and retail trade industries.[20]

text: Within the energy industry, approximately 4 percent of crude oil and petroleum products were shipped by truck in 2012.[41] These shipments are handled by oil and gas logistics firms, which are midstream service providers that also handle transport by pipeline, rail, and barge. Dominant companies in this space include Aux Sable, Bridger Group, DCP Midstream, Enbridge Energy Partners, Enterprise Products Partners, Genesis Energy, Gibson Energy, Inergy Midstream, Kinder Morgan Energy Partners, Oneok Partners, Sunoco Logistics, Targa Midstream Services, TransCanada, and Williams Companies.

text: Agricultural products totaling $118,832,000, or 82.7 percent, were shipped by truck in 2007 (excluding animal feed, cereal grains, and forage products).[42][43] About half of that agricultural freight was shipped by for-hire trucks and half by private trucks.[42] More than 92 percent of prepared foods, including dairy products and prepared fruit, vegetable, and nut products, were moved by truck in 2007.[42][43]

text: Within the health care industry, trucking moved $501,445,000 worth, or 65 percent of the total value, of pharmaceutical products in 2007.[42]

text: Lumber and other wood products totaling $168,913,000 were shipped by truck in 2007, accounting for 91.9 percent of this class of product.[42]

text: Over 80 percent of all communities in the US rely exclusively on trucks to deliver all of their fuel, clothing, medicine, and other consumer goods. The trucking industry employs 10 million people (out of a total national population of 300 million)[44] in jobs that relate directly to trucking. The trucking industry is the industry of small business, considering 93 percent of interstate motor carriers (over 500,000) operate 20 or fewer trucks.[45]

text: Rules and regulations[edit]

text: A division of the U.S. Department of Transportation, the Federal Motor Carrier Safety Administration (FMCSA) regulates nearly all aspects of the trucking industry.[46] Truck drivers are limited by the number of daily and weekly hours they may drive, the roads and highways they may drive upon, and a lower legal definition of drunkenness. The Federal Highway Administration has established 0.04 percent as the blood alcohol concentration (BAC) level at or above which a CMV driver is deemed to be driving under the influence of alcohol.[47] States maintain a BAC level between 0.08 and 0.10 percent for non-CMV drivers. In some states, trucks also have special speed limits, in addition to restrictions on driving in certain lanes (normally the far right lanes of multi-lane highways).[48]

text: Commercial driver's license[edit]

text: Trucks come in many different sizes, creating the need for a truck classification system. Truck drivers are required to have a commercial driver's license (CDL) to operate a CMV carrying more than 16 passengers, carrying a certain amount of hazardous materials, or weighing in excess of 26,000 pounds (12,000 kg).[49] Acquiring a CDL requires a skills test (driving test), and knowledge test (written test) covering the unique handling qualities of driving a large, heavily loaded 18-wheeler (e.g., backing maneuvers), and the mechanical systems required to operate such a vehicle (e.g., air brakes and vehicle inspection procedures).[50]

text: Hours of service[edit]

text: The FMCSA defines a CMV as a single or combination (truck and trailer) vehicle with a gross weight of 10,001 pounds (4,536 kg) or more, or a vehicle used to transport hazardous materials in quantities requiring the vehicle to be marked or placarded under the hazardous materials regulations.[51] The length of time a driver may spend operating a CMV is limited by a set of rules known as the hours of service (HOS). These laws are designed to protect the general motoring public by reducing accidents caused by driver fatigue.

text: The first version of the HOS was enacted in 1938, and four revisions have been made since.[52] The more recent revisions have relied on research into the human circadian rhythm (the tendency for humans to follow a natural 24-hour cycle with 8 hours of uninterrupted sleep).[52] As of July 1, 2013, a driver is limited to 11 hours of actual driving within a 14-hour period, and requires a 30-minute break during the first 8 hours of on duty time. After which he/she must rest for 10 hours.[53] The rules do not explicitly require that a driver must sleep, only that a driver must take a period of "rest" within the sleeper berth or off duty (i.e., at home).

text: Keeping track of a driver's HOS requires the use of a log book.[54] A truck driver's log book is a legally defined form containing a grid outlining the 24-hour day into 15-minute increments. The driver must specify where and when he/she stopped between driving shifts, what duties were performed (if any), along with the driver's name, truck number, company info, and other information. The driver must also present his or her log book to authorities upon request, for inspection. In lieu of a log book, a motor carrier may substitute an electronic on-board recorder to record the driver's hours.[55]

text: Weight, size, and route restrictions[edit]

text: The FMCSA regulates the length, width, and weight limits of CMVs for interstate commercial traffic. Interstate commercial traffic is generally limited to a network of interstate freeways, U.S. highways and state highways known as the National Network (NN). Provided the truck remains on the NN, they are not subject to the state limits. State limits (which can be lower or higher than federal limits) come into effect for intrastate commercial traffic, provided the vehicle is not on the NN.[56]

text: There is no federal height limit, and states may set their own limits which range from 13 feet 6 inches (4.11 m) (mostly on the east coast) to 14 feet (4.3 m) (west coast).,[56] As a result, the majority of trucks are somewhere between 13 feet 6 inches (4.11 m) and 14 feet (4.3 m) high. Truck drivers are responsible for checking bridge height clearances (usually indicated by a warning sign) before passing underneath an overpass or entering a tunnel. Not having enough vertical clearance can result in a "top out" or "bridge hit," causing considerable traffic delays and costly repairs for the bridge or tunnel involved.[57][58]

text: The federal gross weight limit for a Class 8 truck is 80,000 pounds (36,000 kg) (combined weight of truck, trailer, and cargo) with axle weights limited to 12,000 pounds (5,400 kg) (steering axle) and 34,000 pounds (15,000 kg) (tandem axles). Truck drivers are responsible for checking their own vehicle's weight, usually by paying to be weighed at a truck stop scale. CMVs are subject to various state and federal laws regarding limitations on truck length (measured from bumper to bumper), and truck axle length (measured from axle to axle, or fifth wheel kingpin to axle for trailers). The relationship between axle weight and spacing, known as the Federal Bridge Gross Weight Formula, is designed to protect bridges.[59] Truck weights and sizes are checked by state authorities at a weigh station or port-of-entry.

text: Types of vehicles used in trucking[edit]

text: Tractor[edit]

text: The cab and drive axle portion of a large capacity truck and trailer. Since the primary purpose of the Cab is to pull the trailer, it is rightly referred to as a tractor. The various kinds of tractors are Yard, Day, and Sleepers.

text: Bobtail[edit]

text: The bobtail is essentially the front of a tractor-trailer combo. The Bobtail has all the equipment typically seen on the truck of a tractor/trailer set up.

text: Flatbed[edit]

text: The flatbed is essentially a trailer without the enclosed portion on the back. The back or bed is flat and open. These are often referred to as Stake Beds.

text: Panel van[edit]

text: The panel van does come in various sizes. As small as a mini-van and up to having a fairly large box on the bed of a truck. These are seen as box trucks.

text: HotShot[edit]

text: The Hotshot vehicle or truck is essentially a pick-up with a larger load capacity than a personal truck. Hotshots are typically single axle 1-ton to 3-ton trucks, which can be either a dual or single tire.

text: Truck drivers[edit]

text: Definition[edit]

text: Truck drivers are persons employed as the operator of a CMV. CMVs can be of varying shapes and sizes, from 10,000-pound (4,500 kg) pickup trucks assigned to haul specialized or small quantities of freight, all the way up to 80,000-pound (36,000 kg) semi-trailer trucks. Trucks are assigned a class rating based upon the gross vehicle weight rating (GVWR). The facts in this section refer to drivers of "heavy duty" trucks (with a GVWR of at least 26,000 pounds (12,000 kg), which require a commercial driver's license to operate).[49]

text: Working environment[edit]

text: Truck drivers spend up to 11 hours a day driving, and up to 14 hours a day engaged in various duties (including driving time) such as fueling, filling out paperwork, obtaining vehicle repairs, and conducting mandatory vehicle inspections. Long-haul drivers often spend weeks away from home, spending their time off and sleeping at truck stops or rest areas. Driving is relatively dangerous work, as truck drivers account for 12 percent and the highest total number of all work-related deaths, and are five times more likely to die on the job than the average worker.[60] Smoking, lack of exercise, unhealthy eating habits, and work-related injuries also contribute to the driver's generally risk-prone lifestyle.[61] A survey by the National Institutes of Health found 67 percent of long-haul drivers were smokers or had quit smoking.[62]

text: Turnover[edit]

text: In 2006, the U.S. trucking industry employed 1.8 million drivers of heavy trucks.[63] A major problem for the long-haul trucking industry is that a large percentage of these drivers are aging, and are expected to retire. Very few new hires are expected in the near future, resulting in a driver shortage. As of 2005[update], within the long-haul sector, there is an estimated shortage of 20,000 drivers. That shortage was projected to increase to 111,000 by 2014,[64] however the actual shortage of truck drivers in 2014 was around 38,000.[65] The trucking industry (especially the long-haul sector) is also facing an image crisis due to the long working hours, long periods of time away from home, the dangerous nature of the work, and the average earnings compared to other forms of labor (such as construction, which was 1 percent higher than trucking in 2004).[64]

text: Employee turnover within the long-haul trucking industry is notorious for being extremely high. In the 4th quarter of 2005, turnover within the largest carriers in the industry reached a record 136 percent,[66] which means for every 100 new employees hired, 136 quit their jobs. This has resulted in a "revolving door" within most long-haul trucking companies, as drivers are constantly switching jobs or quitting the industry altogether. Driver turnover within the short-haul and less-than-truckload (LTL) industries is considerably less (around 15 percent),[67] mainly due to the better working conditions, higher pay, and unionized workers. One study suggests that larger companies with irregular routes, longer average lengths of hauls, and older equipment experience much higher rates of driver turnover.[67]

text: Serial killings controversy[edit]

text: In 2009, the Federal Bureau of Investigation (FBI) released the results of a five-year-long study (the Highway Serial Killings Initiative) investigating the unsolved murders of prostitutes, hitchhikers, and stranded motorists. Over 500 female victims have been compiled in a database, most of whom were killed or discarded at truck stops, hotels, and roadsides. The FBI has speculated that many of these victims were murdered by long-haul truck drivers, some of whom may be serial killers. Investigators speculate that the easy access to potential victims, mobility, and lack of supervision enjoyed by long-haul truck drivers have contributed to this phenomenon. The head of the initiative, Michael Harrigan, says most of the victims lead high-risk lifestyles (e.g., prostitution) which left them particularly vulnerable. In 2004, the FBI began investigating a string of murders in which the victims were found along the Interstate 40 corridor in Oklahoma and several other states, which sparked the creation of the Highway Serial Killings Initiative.[68]

text: In response to the investigation, the executive vice president of the Owner-Operator Independent Drivers Association, Todd Spencer, said "Truckers are just absolutely outraged that various media sources or the FBI would draw the conclusion that truckers are over-represented in the ranks of serial killers".[69]

text: Trucking organizations[edit]

text:
Teamsters Union
National Motor Freight Traffic Association
Owner-Operator Independent Driver Association
American Trucking Associations
Commercial Vehicle Training Association


document_title: Kyle Lowry

question_text: who did the rockets trade for kyle lowry

root

text: Kyle Lowry

text: High school career[edit]

text: Lowry attended Cardinal Dougherty High School in Philadelphia, where he played point guard for the Cardinal Dougherty Cardinals high school basketball team.

tag: p

text: Considered a five-star recruit by Rivals.com, Lowry was listed as the No. 6 point guard and the No. 28 player in the U.S. in 2004.[2]

text: College career[edit]

text: In his freshman season at Villanova, Lowry was named to the Big East All-Rookie team and was tabbed Philadelphia Big Five Rookie of the Year. In 24 games (3 starts), he averaged 7.5 points, 3.2 rebounds, 2.0 assists and 1.3 steals per game.[3][4]

text: In his sophomore season, he was named to the All Big East Second Team, as well as the First Team All-Big 5. In 33 games (31 starts), he averaged 11.0 points, 4.3 rebounds, 3.7 assists and 2.3 steals per game.[3][4]

text: College statistics[edit]

text:
Year
Team
GP
GS
MPG
FG%
3P%
FT%
RPG
APG
SPG
BPG
PPG

2004–05
Villanova
24
3
23.2
.421
.227
.635
3.2
2.0
1.3
.2
7.5

2005–06
Villanova
33
31
29.3
.466
.444
.786
4.3
3.7
2.3
.2
11.0

tag: table

text: Professional career[edit]

text: Memphis Grizzlies (2006–2009)[edit]

text: Lowry was selected with the 24th overall pick by the Memphis Grizzlies in the 2006 NBA draft. On July 9, 2006, he signed a two-year rookie deal with the Grizzlies, and subsequently joined the Grizzlies for the 2006 NBA Summer League.[5]

text: Lowry scored six points and had 10 rebounds, three assists, two steals and a block on opening night against the New York Knicks, with starting point guard Damon Stoudamire leaving the game early due to injury.[6] However, his rookie season ended after just 10 games due to a broken wrist suffered against the Cleveland Cavaliers on November 21, 2006.[7] Eight days later he underwent successful surgery on it.[8]

text: Lowry looked forward to a long career with the Grizzlies, and was surprised when the team picked another point guard, Mike Conley Jr., with the fourth pick in the 2007 NBA draft.[9] Though Lowry and Conley were friends, Lowry predicted that the difference in their draft positions meant his future would not be on the Grizzlies.[9] On January 25, 2009, the team named Lionel Hollins as the new head coach, and Lowry was told that the team was committed to Conley as a starter.[9]

text: Houston Rockets (2009–2012)[edit]

text: 2008–09 season[edit]

text: At the NBA trade deadline on February 19, 2009, Lowry was traded to the Houston Rockets in a three-team deal involving the Orlando Magic.[10] The Rockets had coveted Lowry since 2006, and general manager Daryl Morey described the trade as "upgrading" the team's point guard position, even though starting point guard Rafer Alston was sent to the Magic, leaving Aaron Brooks as the starter. Lowry bonded with coach Rick Adelman,[9] and made the playoffs for the first time that season, averaging 5.3 points, 2.9 rebounds and 2.5 assists in 13 games[11] as the Rockets lost in seven games to the eventual champion Los Angeles Lakers in the Western Conference semi-finals.

text: 2009–10 season[edit]

text: Lowry averaged 9.1 points, 4.5 assists, and 3.6 rebounds a game the following season as he came off the bench behind Brooks.[12] After the season, he became a restricted free agent, and on July 14, 2010, he signed an offer sheet of four years and $23 million tendered by the Cleveland Cavaliers.[13] The Rockets quickly matched the offer.[12]

text: 2010–11 season[edit]

text: Lowry started 71 games his third season with the Rockets, and his reputation in the league began to solidify.[9] On December 3, 2010, he scored 28 points and had a career-tying 12 assists, three rebounds and two steals in a win against the Memphis Grizzlies. On December 7, 2010, he again had 12 assists, and a career-high six steals, against the Detroit Pistons. On December 17, 2010, Lowry set a new career-high 18 assists, along with 17 points and five steals, in a win against the Grizzlies.

text: On February 16, 2011, Lowry scored a career-high 36 points on 13-of-16 shooting in a loss to his hometown team, the Philadelphia 76ers.

text: On March 20, 2011, Lowry recorded his first triple-double with a 28-point, 10 assist and career-high 11 rebound performance in a win against Utah Jazz. He was named Western Conference Player of the Week for the first time in his career, for his performance between March 14 and March 20, 2011. During the week, he averaged 19.3 points, 7.5 assists and 7.3 rebounds, shooting 52.6 percent and 45 percent on three-pointers, to lead the Rockets to a 4-0 record.

text: 2011–12 season[edit]

text: Despite his initial success on the Rockets, Lowry clashed with head coach Kevin McHale, who replaced Adelman on June 1, 2011. "You go from being successful as hell with one coach", Lowry explained in a 2014 Grantland interview, "and being comfortable with the coach to, yes, I was really successful with Kevin McHale, but I just didn’t do it the right way. If I did it the right way, I would still be in Houston." In 2014, when Lowry was a Toronto Raptor, he apologized to McHale for his behavior, as he was pursued by the Rockets as a free agent.[9]

text: At the end of the 2011–12 season, Lowry missed time due to a bacterial infection, and backup point guard Goran Dragić played well as a starter. With Dragić's emergence, the Rockets decided that Lowry could be traded to clear salary cap space and to gain draft picks.[9]

text: Toronto Raptors (2012–present)[edit]

text: 2012–13 season[edit]

text: On July 11, 2012, Lowry was traded to the Toronto Raptors in exchange for Gary Forbes and a future first round pick.[14] Lowry averaged over 23 points and seven assists through the first three games of the season, but was injured during the team's fourth game, a loss to the Oklahoma City Thunder on November 6, 2012.[15] Upon his return he came off the bench behind José Calderón, but regained the starting position when Calderón was traded in a three-team deal on January 30, 2013 that brought Memphis Grizzlies small forward Rudy Gay to the Raptors.[16] Despite the trade, which was meant to help the struggling Raptors return to relevance, the team finished the season with a 34-48 record, missing the playoffs.

text: On May 31, 2013, Masai Ujiri was hired as the Raptors' new general manager, replacing Bryan Colangelo. Ujiri believed that Lowry had the potential to be a star, but found that his reputation around the NBA had more to do with his history of clashing with coaches and his body language than his talent. Ujiri challenged Lowry during meetings that off-season to be a better player and leader. "Do you want to be a $3 million player, $2 million player for the rest of your career", Ujiri remembers asking Lowry, "...or do you want to be a $10 million player or more?" Lowry also received mentorship from Chauncey Billups, who Lowry remembers "pushed me mentally to challenge myself." Receptive to the advice he had received from Ujiri and others, Lowry looked forward to the upcoming season, entering training camp healthy for the first time in several seasons.[9]

text: 2013–14 season[edit]

text: The Raptors started the 2013–14 season with a 6-12 record, until Gay, the team's leading scorer, was traded to the Sacramento Kings. Following the trade, Raptors shooting guard DeMar DeRozan approached Lowry and the two decided to take ownership of the team, knowing they could both be traded if the team's management decided to rebuild rather than compete for a playoff spot.[9] Lowry's name was linked to several teams, most frequently the New York Knicks, in trade rumours, but the Knicks were reportedly unwilling to send a first round pick to Toronto in exchange for Lowry.[9] The post-Gay Raptors quickly emerged as one of the best teams in the Eastern Conference, and many cited Lowry's strong play and leadership as a significant factor in their success.[17] The team finished the season with a franchise-best 48-34 record, third in the Eastern Conference and first in the Atlantic Division for the second time in franchise history. They made the playoffs for the first time since 2008, but lost in the first round to the Brooklyn Nets after Lowry's potential game-winning shot was blocked by Paul Pierce in Game 7. Despite a disappointing end to the season, Lowry averaged career-best 17.9 points, 7.4 assists and 4.7 rebounds during the regular season and 21.1 points, 4.7 assists and 4.7 rebounds during the playoffs.

text: Lowry entered the off-season as one of the NBA's most coveted free agents, attracting interest from the Miami Heat, Houston Rockets and other teams.[18] On July 10, 2014, he re-signed with the Raptors to a four-year, $48 million contract.[19][20]

text: 2014–15 season[edit]

text: The Raptors and Lowry continued their strong play into the next season, and the team once again emerged as a top seed in the Eastern Conference. On November 7, 2014, Lowry became the team's all-time leader in triple-doubles with a 13-point, 10 assist and 11 rebound performance in a win against the Washington Wizards. It was Lowry's sixth career triple-double and his fourth as a Raptor, passing Damon Stoudamire, who had the previous franchise record of three.[21] On December 3, he scored a career-high 39 points on 13-of-22 shooting in a win against the Utah Jazz.[22] On January 5, 2015, Lowry was named the Eastern Conference Player of the Month for December 2014, making him only the second Raptor, after Chris Bosh, to receive this recognition. Lowry averaged 22.3 points, 8.9 assists and 4.2 rebounds during the month, winning Player of the Week during the first week and helping lead the Raptors to an 11-4 record.[23] On January 22, 2015, Lowry became a first-time All-Star when he was announced as an Eastern Conference starter in the 2015 NBA All-Star Game.[24] He became only the third Raptor to be voted in as a starter, after Vince Carter and Bosh.[25] On February 5, 2015, the NBA announced that Lowry would also participate in the 2015 NBA All-Star Weekend Skills Challenge as part of the NBA All-Star Weekend.[25] Lowry finished the All-Star game with 10 points, a team-high eight assists, three rebounds and four steals in a loss to the West, completing his first in-game dunk since 2009.[26]

text: On March 16, 2015, Lowry recorded his seventh career triple-double with 20 points, 11 rebounds and 10 assists in a 117-98 win over the Indiana Pacers.[27] The Raptors finished the 2014–15 season with a franchise-best 49-33 record, fourth in the East and first in the Atlantic, but were swept in the first round by the Washington Wizards, despite entering the series with homecourt advantage. Lowry averaged 17.8 points, 6.8 assists and 4.7 rebounds in 70 games during the regular season, but a disappointing 12.3 points, as well as 4.8 assists and 5.5 rebounds, in the playoffs, with many questioning his health during the series.[28]

text: 2015–16 season[edit]

text: Following his disappointing performance in the playoffs, Lowry entered the 2015–16 season with a noticeably slimmer physique, looking "as trim and fit as he ever has during his nearly decade-long NBA career", according to Toronto Sun writer, Ryan Wolstat.[29] Lowry explained that he wanted to be prepared "for 82 games and a long playoff run."[30] On November 3, he scored a game-high 27 points against the Dallas Mavericks as the Raptors started 4–0 for the first time in franchise history (the streak eventually ended with five wins).[31] On December 5, Lowry scored a then career-high 41 points and made six three-pointers in a loss to the Golden State Warriors.[32]

text: On January 18, 2016, Lowry tied his career-high of made three-pointers in game with seven, scoring a game-high 31 points in total, in a 112–100 win over the Brooklyn Nets.[33] On January 21, he was named as a starter to the Eastern Conference All-Star team for the 2016 NBA All-Star Game.[34] He was also later named a contestant in the Three-Point Contest, making him the third Raptors player to participate in this event.[35] On February 1, in a 112–93 loss to the Denver Nuggets, Lowry passed Alvin Williams for second all-time on the Raptors' assists list.[36] The following day, Lowry and teammate DeMar DeRozan were selected as co-winners for Eastern Conference Player of the Month for January. The pair helped the Raptors go 12–2 during the month and record a franchise-record 11-game win streak.[37] On February 14, Lowry finished his second All-Star game, held in Toronto for the first time, with 14 points, 10 assists, five rebounds and two steals in the East's 196–173 loss to the West. On February 22, he recorded his eighth career triple-double (sixth as a Raptor) with 22 points, 11 assists and 11 rebounds in a 122–95 win over the New York Knicks.[38] Four days later, he scored a career-high 43 points, on 15-of-20 shooting, and had nine assists, five rebounds and four steals in a 99–97 win over the Cleveland Cavaliers.[39] On February 29, he was named Eastern Conference Player of the Week for games played from February 22–28.[40] On March 21, he was again named Eastern Conference Player of the Week, for games played from March 14–20, becoming the first Raptors player since Chris Bosh in 2009–10 to win the award multiple times in the same season.[41] On March 30, he recorded 17 points, 11 assists and six rebounds in a 105–97 win over the Atlanta Hawks, helping the Raptors reach 50 wins for the first time in franchise history.[42] The team finished the regular season with a 56–26 record, good for first in the Atlantic Division for the third consecutive year, and second in the Eastern Conference.

text: Lowry entered the playoffs suffering from bursitis in his shooting elbow, as he shot a mere 32% from the field over the final 10 games of the regular season.[43] His poor shooting continued into the postseason as the Raptors faced the Indiana Pacers in the first round. Despite Lowry's struggles, the Raptors defeated the Pacers in seven games, winning their second playoff series in franchise history, their first since 2001, and their first seven-game series.[44] In Game 3 of the Raptors' second-round series against the Miami Heat, Lowry broke out of his shooting slump with a 33-point performance on 11-of-19 shooting, helping the Raptors win 95–91 and go up 2–1 on the series.[45] In Game 6 of the series, he tied his playoff career high with 36 points on 12-of-27 shooting in a 103–91 loss, as the Heat forced a Game 7 in Toronto.[46] In Game 7 of the series, he scored 35 points on 11-of-20 shooting, to go along with nine assists, seven rebounds and four steals, in a 116–89 win, helping the Raptors advance to the Eastern Conference Finals for the first time in franchise history.[47] In Game 4 of the Conference Finals against the Cleveland Cavaliers, Lowry scored 35 points on 14-of-20 shooting to help the Raptors win 105–99 and tie the series at 2–2.[48] In Game 6 of the series, Lowry again scored 35 points, but was unable to force a Game 7, with the 113–87 loss knocking the Raptors out of the playoffs with a 4–2 defeat.[49] Lowry capped off his strong season by earning All-NBA third team honors. With his first selection to the All-NBA team, he joined Vince Carter and Chris Bosh as the only players in franchise history to receive this recognition.[50]

text: 2016–17 season[edit]

text: On November 28, 2016, Lowry set a franchise record by hitting all six of his three-pointers for a game-high 24 points in a 122–95 win over the Philadelphia 76ers.[51][52] On December 9, he scored 21 of his then season-high 34 points in the second half of the Raptors' 101–94 win over the Boston Celtics.[53] He set a new season high on December 23, scoring 36 points, including 19 in the fourth quarter, to lead the Raptors to a 104–98 victory over the Utah Jazz.[54][55] On January 1, 2017, he scored 20 of his season-high 41 points in the fourth quarter of the Raptors' 123–114 win over the Los Angeles Lakers. He also had nine rebounds and seven assists, and went 5-of-6 from three-point range.[56] On February 5, 2017, he recorded his ninth career triple-double with 15 points, 11 rebounds and 11 assists in a 103–95 win over the Brooklyn Nets.[57] The following day in the Raptors' 118–109 win over the Los Angeles Clippers, Lowry became the Raptors' franchise leader in three-pointers when he buried one from beyond the arc with 5:27 to play in the first half. His third three-pointer of the night gave him 802 in a Toronto uniform, surpassing Morris Peterson's mark.[58] On April 5, 2017, he returned from an 18-game absence with a wrist injury, played 42 minutes and had 27 points and 10 assists to help the Raptors overcome a 20-point first-half deficit in a 105–102 victory over the Detroit Pistons.[59]

text: In the Raptors' second-round playoff series against the Cleveland Cavaliers, Lowry sprained his left ankle in the third quarter of Game 2, and aggravated the injury while trying to warm up for Game 3. He was not active for Game 4 and thus could not assist the Raptors in trying to avoid a series sweep; with a 109–102 loss to the Cavaliers in Game 4, the Raptors bowed out of the playoffs with a 4–0 defeat.[60]

text: Following the playoffs, Lowry declined his $12 million player option for the 2017–18 season and became an unrestricted free agent.[61]

text: 2017–18 season[edit]

text: On July 7, 2017, Lowry re-signed with the Raptors to a three-year, $100 million contract.[62][63]

text: National team career[edit]

text: Lowry was a member of the U.S. men's national team that won gold at the 2016 Summer Olympics.[64] He earned praise for his defense and leadership during the tournament, with head coach Mike Krzyzewski calling him the team's "unsung hero" and assistant coach Jim Boeheim naming him "the best team player out of everybody."[65]

text: Player profile[edit]

text: Lowry's tenacious playing style has often earned him comparisons to a pit bull or bulldog, with many citing his toughness, leadership and instinct for winning plays on the court.[1][66][67] Lowry's Villanova teammate Curtis Sumpter remembers "he was just so tough. He wasn’t the flashy guy. He wasn’t coming down to try and throw 150 crossovers and make all these fantastic moves. That wasn’t his game. He was just so solid and able to read the defenses and make the pass at the right time and get guys in the right position to score."[9] In 2014, Zach Lowe of Grantland wrote that Lowry "was probably the best point guard in the Eastern Conference from start to finish [of the 2013–14 season], raining off-the-bounce 3s, getting Toronto into its offense, toning down the wild gambles on defense, and using that stubby little body to draw more charges than anyone."[68]

text: Lowry is considered a strong rebounder for his position, as well as a determined defender.[3][69] He holds the Toronto Raptors' franchise record for triple-doubles,[70] as well as the most made three-point field goals in a season, for the 2013–14 season.[17]

text: Awards and achievements[edit]

text:
All-NBA Third Team: 2016
NBA All-Star: 2015, 2016, 2017
NBA Eastern Conference Player of the Month: December 2014; January 2016
NBA Eastern Conference Player of the Week: January 27–February 2, 2014; December 1–7, 2014;[71] February 22–28, 2016; March 14–20, 2016
NBA Western Conference Player of the Week: March 14–20, 2011[72]

tag: ul

text: Other achievements[edit]

text:
Toronto's all-time leader in triple-doubles (five)[70]
Toronto's leader in three-point field goals in a season (2013–14)[17]
George Gross Sportsman of the Year award[73]

text: NBA career statistics[edit]

text:
Legend

  GP
Games played
  GS
Games started
 MPG
Minutes per game

 FG%
Field goal percentage
 3P%
3-point field goal percentage
 FT%
Free throw percentage

 RPG
Rebounds per game
 APG
Assists per game
 SPG
Steals per game

 BPG
Blocks per game
 PPG
Points per game
 Bold
Career high

text: Regular season[edit]

text:
Year
Team
GP
GS
MPG
FG%
3P%
FT%
RPG
APG
SPG
BPG
PPG

2006–07
Memphis
10
0
17.5
.368
.375
.893
3.1
3.2
1.4
.1
5.6

2007–08
Memphis
82
9
25.5
.432
.257
.698
3.0
3.6
1.1
.3
9.6

2008–09
Memphis
49
21
21.9
.412
.246
.801
2.3
3.6
1.0
.2
7.6

2008–09
Houston
28
0
21.7
.475
.276
.800
2.8
3.5
.8
.3
7.6

2009–10
Houston
68
0
24.3
.397
.272
.827
3.6
4.5
.9
.1
9.1

2010–11
Houston
75
71
34.2
.426
.376
.765
4.1
6.7
1.4
.3
13.5

2011–12
Houston
47
38
32.1
.409
.374
.864
4.5
6.6
1.6
.3
14.3

2012–13
Toronto
68
52
29.7
.401
.362
.795
4.7
6.4
1.4
.4
11.6

2013–14
Toronto
79
79
36.2
.423
.380
.813
4.7
7.4
1.5
.2
17.9

2014–15
Toronto
70
70
34.5
.412
.338
.808
4.7
6.8
1.6
.2
17.8

2015–16
Toronto
77
77
37.0
.427
.388
.811
4.7
6.4
2.1
.4
21.2

2016–17
Toronto
60
60
37.4
.464
.412
.819
4.8
7.0
1.5
.3
22.4

Career
713
477
30.9
.424
.364
.799
4.1
5.8
1.4
.3
14.3

All-Star
3
2
24.0
.432
.344
.000
3.7
6.0
2.7
.3
14.3

text: Playoffs[edit]

text:
Year
Team
GP
GS
MPG
FG%
3P%
FT%
RPG
APG
SPG
BPG
PPG

2009
Houston
13
0
19.5
.333
.250
.742
2.9
2.5
.9
.1
5.3

2014
Toronto
7
7
38.7
.404
.395
.878
4.7
4.7
.9
.0
21.1

2015
Toronto
4
4
32.8
.316
.217
.727
5.5
4.8
1.3
.0
12.3

2016
Toronto
20
20
38.3
.397
.304
.750
4.7
6.0
1.6
.2
19.1

2017
Toronto
8
8
37.6
.462
.342
.818
3.1
5.9
1.5
.5
15.8

Career
52
39
33.1
.394
.314
.785
4.1
4.8
1.3
.2
14.9


document_title: Kennel Club breed groups

question_text: how many english kennel club groups are there

text: Kennel Club breed groups

text: This article does not cite any sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (November 2010) (Learn how and when to remove this template message)

text: The Kennel Club in the United Kingdom has a seven-group system. This is a system shared with many other non-Fédération Cynologique Internationale (FCI) kennel clubs. All of these groups have breeds with a common original purpose.

text: System: groups and breeds[edit]

text: The Kennel Club's seven-group system is shared with many other non-FCI members. They all contain dogs that were bred for a specific purpose. These groups are less broken down than the FCI. This is the hierarchy:

text: Example Breed: Norwegian Buhund

text:
Group: Pastoral Group
Breed: Norwegian Buhund

text: Groups[edit]

text: The Kennel Club groups are as follows:

text:
Hound Group
Terrier Group
Working Group
Pastoral Group
Gundog Group
Utility Group
Toy Group

tag: ol


document_title: Eye (cyclone)

question_text: which part of the hurricane is the warmest

text: Eye (cyclone)

text: Structure[edit]

text: A typical tropical cyclone will have an eye of approximately 30–65 km (20–40 mi) across, usually situated at the geometric center of the storm. The eye may be clear or have spotty low clouds (a clear eye), it may be filled with low- and mid-level clouds (a filled eye), or it may be obscured by the central dense overcast. There is, however, very little wind and rain, especially near the center. This is in stark contrast to conditions in the eyewall, which contains the storm's strongest winds.[3] Due to the mechanics of a tropical cyclone, the eye and the air directly above it are warmer than their surroundings.[4]

text: While normally quite symmetric, eyes can be oblong and irregular, especially in weakening storms. A large ragged eye is a non-circular eye which appears fragmented, and is an indicator of a weak or weakening tropical cyclone. An open eye is an eye which can be circular, but the eyewall does not completely encircle the eye, also indicating a weakening, moisture-deprived cyclone. Both of these observations are used to estimate the intensity of tropical cyclones via Dvorak analysis.[5] Eyewalls are typically circular; however, distinctly polygonal shapes ranging from triangles to hexagons occasionally occur.[6]

text: While typical mature storms have eyes that are a few dozen miles across, rapidly intensifying storms can develop an extremely small, clear, and circular eye, sometimes referred to as a pinhole eye. Storms with pinhole eyes are prone to large fluctuations in intensity, and provide difficulties and frustrations for forecasters.[7]

text: Small/minuscule eyes—those less than 10 nmi (19 km, 12 mi) across—often trigger eyewall replacement cycles, where a new eyewall begins to form outside the original eyewall. This can take place anywhere from fifteen to hundreds of kilometers (ten to a few hundred miles) outside the inner eye. The storm then develops two concentric eyewalls, or an "eye within an eye". In most cases, the outer eyewall begins to contract soon after its formation, which chokes off the inner eye and leaves a much larger but more stable eye. While the replacement cycle tends to weaken storms as it occurs, the new eyewall can contract fairly quickly after the old eyewall dissipates, allowing the storm to re-strengthen. This may trigger another re-strengthen cycle of eyewall replacement.[8]

text: Eyes can range in size from 370 km (230 mi) (Typhoon Carmen)[9] to a mere 3.7 km (2.3 mi) (Hurricane Wilma) across.[10] While it is uncommon for storms with large eyes to become very intense, it does occur, especially in annular hurricanes. Hurricane Isabel was the eleventh most powerful North Atlantic hurricane in recorded history, and sustained a large, 65–80 km (40–50 mi)-wide eye for a period of several days.[11]

text: Formation and detection[edit]

text: Tropical cyclones typically form from large, disorganized areas of disturbed weather in tropical regions. As more thunderstorms form and gather, the storm develops rainbands which start rotating around a common center. As the storm gains strength, a ring of stronger convection forms at a certain distance from the rotational center of the developing storm. Since stronger thunderstorms and heavier rain mark areas of stronger updrafts, the barometric pressure at the surface begins to drop, and air begins to build up in the upper levels of the cyclone.[12] This results in the formation of an upper level anticyclone, or an area of high atmospheric pressure above the central dense overcast. Consequently, most of this built up air flows outward anticyclonically above the tropical cyclone. Outside the forming eye, the anticyclone at the upper levels of the atmosphere enhances the flow towards the center of the cyclone, pushing air towards the eyewall and causing a positive feedback loop.[12]

text: However, a small portion of the built-up air, instead of flowing outward, flows inward towards the center of the storm. This causes air pressure to build even further, to the point where the weight of the air counteracts the strength of the updrafts in the center of the storm. Air begins to descend in the center of the storm, creating a mostly rain-free area—a newly formed eye.[12]

text: There are many aspects of this process which remain a mystery. Scientists do not know why a ring of convection forms around the center of circulation instead of on top of it, or why the upper-level anticyclone only ejects a portion of the excess air above the storm. Many theories exist as to the exact process by which the eye forms: all that is known for sure is that the eye is necessary for tropical cyclones to achieve high wind speeds.[12]

text: The formation of an eye is almost always an indicator of increasing tropical cyclone organisation and strength. Because of this, forecasters watch developing storms closely for signs of eye formation.

text: For storms with a clear eye, detection of the eye is as simple as looking at pictures from a weather satellite. However, for storms with a filled eye, or an eye completely covered by the central dense overcast, other detection methods must be used. Observations from ships and Hurricane Hunters can pinpoint an eye visually, by looking for a drop in wind speed or lack of rainfall in the storm's center. In the United States, South Korea, and a few other countries, a network of NEXRAD Doppler weather radar stations can detect eyes near the coast. Weather satellites also carry equipment for measuring atmospheric water vapor and cloud temperatures, which can be used to spot a forming eye. In addition, scientists have recently discovered that the amount of ozone in the eye is much higher than the amount in the eyewall, due to air sinking from the ozone-rich stratosphere. Instruments sensitive to ozone perform measurements, which are used to observe rising and sinking columns of air, and provide indication of the formation of an eye, even before satellite imagery can determine its formation.[13]

text: Associated phenomena[edit]

text: Eyewall replacement cycles[edit]

text: Eyewall replacement cycles, also called concentric eyewall cycles, naturally occur in intense tropical cyclones, generally with winds greater than 185 km/h (115 mph), or major hurricanes (Category 3 or higher on the Saffir–Simpson hurricane scale). When tropical cyclones reach this intensity, and the eyewall contracts or is already sufficiently small (see above), some of the outer rainbands may strengthen and organize into a ring of thunderstorms—an outer eyewall—that slowly moves inward and robs the inner eyewall of its needed moisture and angular momentum. Since the strongest winds are located in a cyclone's eyewall, the tropical cyclone usually weakens during this phase, as the inner wall is "choked" by the outer wall. Eventually the outer eyewall replaces the inner one completely, and the storm can re-intensify.[8]

text: The discovery of this process was partially responsible for the end of the U.S. government's hurricane modification experiment Project Stormfury. This project set out to seed clouds outside the eyewall, causing a new eyewall to form and weakening the storm. When it was discovered that this was a natural process due to hurricane dynamics, the project was quickly abandoned.[8]

text: Almost every intense hurricane undergoes at least one of these cycles during its existence. Hurricane Allen in 1980 went through repeated eyewall replacement cycles, fluctuating between Category 5 and Category 3 status on the Saffir-Simpson scale several times. Hurricane Juliette was a rare documented case of triple eyewalls.[14]

text: Moats[edit]

text: A moat in a tropical cyclone is a clear ring outside the eyewall, or between concentric eyewalls, characterized by subsidence—slowly sinking air—and little or no precipitation. The air flow in the moat is dominated by the cumulative effects of stretching and shearing. The moat between eyewalls is an area in the storm where the rotational speed of the air changes greatly in proportion to the distance from the storm's center; these areas are also known as rapid filamentation zones. Such areas can potentially be found near any vortex of sufficient strength, but are most pronounced in strong tropical cyclones.[15]

text: Eyewall mesovortices[edit]

text: Eyewall mesovortices are small scale rotational features found in the eyewalls of intense tropical cyclones. They are similar, in principle, to small "suction vortices" often observed in multiple-vortex tornadoes.[16] In these vortices, wind speeds may be greater than anywhere else in the eyewall.[17] Eyewall mesovortices are most common during periods of intensification in tropical cyclones.[16]

text: Eyewall mesovortices often exhibit unusual behavior in tropical cyclones. They usually rotate around the low pressure center, but sometimes they remain stationary. Eyewall mesovortices have even been documented to cross the eye of a storm. These phenomena have been documented observationally,[18] experimentally,[16] and theoretically.[19]

text: Eyewall mesovortices are a significant factor in the formation of tornadoes after tropical cyclone landfall. Mesovortices can spawn rotation in individual thunderstorms (a mesocyclone), which leads to tornadic activity. At landfall, friction is generated between the circulation of the tropical cyclone and land. This can allow the mesovortices to descend to the surface, causing tornadoes.[20]

text: Stadium effect[edit]

text: The stadium effect is a phenomenon observed in strong tropical cyclones. It is a fairly common event, where the clouds of the eyewall curve outward from the surface with height. This gives the eye an appearance resembling an open dome from the air, akin to a sports stadium. An eye is always larger at the top of the storm, and smallest at the bottom of the storm because the rising air in the eyewall follows isolines of equal angular momentum, which also slope outward with height.[21][22][23] In tropical cyclones with very small eyes, the sloping phenomenon is much more pronounced.

text: Eye-like features[edit]

text: An eye-like structure is often found in intensifying tropical cyclones. Similar to the eye seen in hurricanes or typhoons, it is a circular area at the circulation center of the storm in which convection is absent. These eye-like features are most normally found in intensifying tropical storms and hurricanes of Category 1 strength on the Saffir-Simpson scale. For example, an eye-like feature was found in Hurricane Beta when the storm had maximum wind speeds of only 80 km/h (50 mph), well below hurricane force.[24] The features are typically not visible on visible wavelengths or infrared wavelengths from space, although they are easily seen on microwave satellite imagery.[25] Their development at the middle levels of the atmosphere is similar to the formation of a complete eye, but the features might be horizontally displaced due to vertical wind shear.[26][27]

text: Hazards[edit]

text: Though the eye is by far the calmest part of the storm, with no wind at the center and typically clear skies, over the ocean it is possibly the most hazardous area. In the eyewall, wind-driven waves all travel in the same direction. In the center of the eye, however, the waves converge from all directions, creating erratic crests that can build on each other to become rogue waves. The maximum height of hurricane waves is unknown, but measurements during Hurricane Ivan when it was a Category 4 hurricane estimated that waves near the eyewall exceeded 40 m (130 ft) from peak to trough.[28]

text: A common mistake, especially in areas where hurricanes are uncommon, is for residents to exit their homes to inspect the damage while the calm eye passes over, only to be caught off guard by the violent winds in the opposite eyewall.[29]

text: Other cyclones[edit]

text: Though only tropical cyclones have structures officially termed "eyes", there are other weather systems that can exhibit eye-like features.[1][30]

text: Polar lows[edit]

text: Polar lows are mesoscale weather systems, typically smaller than 1,000 km (600 mi) across, found near the poles. Like tropical cyclones, they form over relatively warm water and can feature deep convection and winds of gale force or greater. Unlike storms of tropical nature, however, they thrive in much colder temperatures and at much higher latitudes. They are also smaller and last for shorter durations, with few lasting longer than a day or so. Despite these differences, they can be very similar in structure to tropical cyclones, featuring a clear eye surrounded by an eyewall and bands of rain and snow.[31].

text: Extratropical cyclones[edit]

text: Extratropical cyclones are areas of low pressure which exist at the boundary of different air masses. Almost all storms found at mid-latitudes are extratropical in nature, including classic North American nor'easters and European windstorms. The most severe of these can have a clear "eye" at the site of lowest barometric pressure, though it is usually surrounded by lower, non-convective clouds and is found near the back end of the storm.[32]

text: Subtropical cyclones[edit]

text: Subtropical cyclones are low-pressure systems with some extratropical characteristics and some tropical characteristics. As such, they may have an eye while not being truly tropical in nature. Subtropical cyclones can be very hazardous, generating high winds and seas, and often evolve into fully tropical cyclones. For this reason, the National Hurricane Center began including subtropical storms in its naming scheme in 2002.[33]

text: Tornadoes[edit]

text: Tornadoes are destructive, small-scale storms, which produce the fastest winds on earth. There are two main types—single-vortex tornadoes, which consist of a single spinning column of air, and multiple-vortex tornadoes, which consist of small "suction vortices," resembling mini-tornadoes themselves, all rotating around a common center. Both of these types of tornadoes are theorized to have calm eyes. These theories are supported by doppler velocity observations by weather radar and eyewitness accounts.[34][35]

text: Extraterrestrial vortices[edit]

text: NASA reported in November 2006 that the Cassini spacecraft observed a "hurricane-like" storm locked to the south pole of Saturn with a clearly defined eyewall. The observation was particularly notable as eyewall clouds had not previously been seen on any planet other than Earth (including a failure to observe an eyewall in the Great Red Spot of Jupiter by the Galileo spacecraft).[36] In 2007, very large vortices on both poles of Venus were observed by the Venus Express mission of the European Space Agency to have a dipole eye structure.[37]