Hail is a form of precipitation which consists of balls or irregular lumps of ice (hailstones). Nature, in the broadest sense is equivalent to the natural world, physical universe, material world or material universe. The weather is a set of all the phenomena occurring in a given Atmosphere at a given Time. A season is one of the major divisions of the Year, generally based on yearly periodic changes in Weather. Spring is one of the four Temperate Seasons Spring marks the transition from Winter into Summer. Summer is one of the four Temperate Seasons Summer marks the warmest time of year with the longest days Autumn (also known as fall in North American English) is one of the four Temperate Seasons Autumn marks the transition from Summer Winter is one of the four Seasons of Temperate zones Calculated astronomically, it begins on the Solstice and ends on the Equinox The Tropics are centered on the Equator and limited in Latitude by the Tropic of Cancer in the northern hemisphere at approximately 23°26' (23 The dry season is a term commonly used when describing the weather in the Tropics. A wet season or rainy season is a Season in which the average Rainfall in a region is significantly increased A storm is any disturbed state of an astronomical body's atmosphere, especially affecting its surface and strongly implying Severe weather. A tornado is a violent rotating column of air which is in contact with both the surface of the earth and a Cumulonimbus cloud or in rare cases the base of a Cumulus A tropical cyclone is a storm system characterized by a low pressure center and numerous Thunderstorms that produce strong winds and Flooding Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are a group of Cyclones defined as synoptic scale low A winter storm is an event in which the dominant varieties of precipitation are forms that only occur at cold Temperatures such as Snow or A blizzard is a severe Winter storm condition characterized by low Temperatures strong Winds and heavy blowing Snow Blizzards are formed when An ice storm is a type of Winter storm characterized by Freezing rain. In Meteorology, precipitation (also known as one class of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric Fog is a cloud that is in contact with the ground Stratus clouds are usually the only clouds that touch the ground Drizzle (also called mizzle) is light precipitation consisting of liquid water drops smaller than that of Rain, and generally smaller than 0 Rain is Liquid precipitation. On Earth it is the condensation of atmospheric Water vapor into drops heavy enough to fall often making it to Freezing rain is a type of precipitation that begins as Snow at higher altitude falling from a Cloud towards earth melts completely on its way down while passing Ice pellets are a form of precipitation consisting of small Translucent ice balls "Snowfall" redirects here For other uses see Snow (disambiguation or Snowfall (disambiguation. Graupel (also called snow pellets) refers to precipitation that forms when supercooled Droplets of Water condense on a Snowflake forming This is a list of meteorology topics. The terms relate to Meteorology, the Interdisciplinary scientific study of the atmosphere that focuses on Meteorology (from Greek grc μετέωρος metéōros, "high in the sky" and grc -λογία -logia) is the Interdisciplinary Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location Climate encompasses the temperatures humidity rainfall atmospheric particle count and numerous other meteorogical factors in a given region over long periods of Air pollution is the human introduction into the atmosphere of Chemicals Particulate matter, or Biological materials that cause harm or discomfort In Meteorology, precipitation (also known as one class of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric Hailstones on Earth usually consist mostly of water ice and measure between 5 and 150 millimeters in diameter, with the larger stones coming from severe thunderstorms. EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 Ice is a Solid phase, usually crystalline, of a Non-metalic substance that is liquid or gas at Room temperature, such as Ammonia ^[1] Hail is only produced by cumulonimbi (thunderclouds), usually at the front of the storm system, and is composed of transparent ice or alternating layers of transparent and translucent ice at least 1 mm thick. Cumulonimbus (Cb is a type of Cloud that is tall dense and involved in Thunderstorms and other intense Weather. The METAR code for hail 5 mm or greater in diameter is GR, while smaller hailstones and graupel are coded GS. METAR (METeorological Aviation Report is a format for reporting Weather information Graupel (also called snow pellets) refers to precipitation that forms when supercooled Droplets of Water condense on a Snowflake forming Unlike ice pellets, they are layered and can be irregular and clumped together. Ice pellets are a form of precipitation consisting of small Translucent ice balls

Hail formation

A large hailstone, about 6 cm (2. 36 in) in diameter

Hail forms in storm clouds when supercooled water droplets freeze on contact with condensation nuclei, such as dust. A cloud is a visible mass of droplets or frozen crystals floating in the atmosphere above the surface of the Earth or another Planetary body Water is a common Chemical substance that is essential for the survival of all known forms of Life. Cloud condensation nuclei or CCN s (also known as cloud seeds) are small particles (typically 0 Dust is a general name for minute Solid particles with Diameters less than 500 micrometers. The storm's updraft blows the hailstones to the upper part of the cloud. An updraft or downdraft ( air pocket) is the vertical movement of Air as a Weather related phenomenon The updraft dissipates and the hailstones fall down, back into the updraft, and are lifted up again. The hailstone gains an ice layer and grows increasingly larger with each ascent. Once a hailstone becomes too heavy to be supported by the storm's updraft, it falls out of the cloud.

In large hailstones, latent heat released by further freezing may melt the outer shell of the hailstone. In Thermochemistry, latent heat is the amount of Energy in the form of Heat released or absorbed by a substance during a change of phase The hailstone then may undergo 'wet growth', where the liquid outer shell collects other smaller hailstones.

Ideal conditions for hail formation

The largest hailstone ever measured, 17. This is a list of Weather records, a list of the most extreme occurrences of weather phenomena for various categories 8 centimetres (7. 0 in) in diameter with a 47. Geometry, a diameter of a Circle is any straight Line segment that passes through the center of the circle and whose Endpoints are on the 6 centimetres (19 in) circumference. The circumference is the distance around a closed Curve. Circumference is a kind of Perimeter.

Hail forms in strong thunderstorm clouds, particularly those with intense updrafts, high liquid water content, great vertical extent, large water droplets, and where a good portion of the cloud layer is below freezing 0 °C (32 °F). An updraft or downdraft ( air pocket) is the vertical movement of Air as a Weather related phenomenon The growth rate is maximized at about −13 °C (9 °F), and becomes vanishingly small much below −30 °C (−22 °F) as supercooled water droplets become rare. For this reason, hail is most common in mid-latitudes during early summer where surface temperatures are warm enough to promote the instability associated with strong thunderstorms, but the upper atmosphere is still cool enough to support ice. Accordingly, hail is actually less common in the tropics despite a much higher frequency of thunderstorms than in the mid-latitudes because the atmosphere over the tropics tends to be warmer over a much greater depth. Also, entrainment of dry air into strong thunderstorms over continents can increase the frequency of hail by promoting evaporational cooling which lowers the freezing level of thunderstorm clouds giving hail a larger volume to grow in. See Entrainment for other types Entrainment is a phenomenon of the Atmosphere which occurs when a turbulent flow captures a non-turbulent flow

Hail is also much more common along mountain ranges because mountains force horizontal winds upwards (known as orographic lifting), thereby intensifying the updrafts within thunderstorms and making hail more likely. Orographic lift occurs when an Air mass is forced from a low Elevation to a higher elevation as it moves over rising terrain One of the most notorious regions for large hail is the mountainous northern India and Bangladesh, which have reported more hail-related deaths than anywhere else in the world and also some of the largest hailstones ever measured. India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country ( Bengali: বাংলাদেশ inc-Latn Bangladesh) officially Mainland China is also notorious for killer hailstorms. Mainland China, Continental China, the Chinese mainland or simply the mainland, is a geopolitical term synonymous with the area that is under the jurisdiction In North America, hail is most common in the area where Colorado, Nebraska, and Wyoming meet, known as "Hail Alley. The State of Colorado ( or chiefly by nonresidents) is a state located in the Rocky Mountain region of the United States of America. Nebraska ( is a state located on the Great Plains of the Midwestern United States and The State of Wyoming ( is a sparsely populated state in the western region of the United States. " ^[2] Cheyenne, Wyoming is North America's most hail-prone city with an average of nine to ten hailstorms per season. Cheyenne ( /ʃaɪˈæn/ or /ʃaɪˈɛn/) is the capital of the U ^[3]

Hailstones, while most commonly only a few millimetres in diameter, can sometimes grow to 15 centimetres (6 in) and weigh more than . Geometry, a diameter of a Circle is any straight Line segment that passes through the center of the circle and whose Endpoints are on the 5 kilograms (1. 1 lb)^[4]. Pea or golf ball-sized hailstones are not uncommon in severe storms. A pea (inaccurately called a '''sweet pea''' by food distubutors is most commonly the small spherical Seed or the seed-pod of the Legume Pisum Hail can do serious damage, notably to automobiles, skylights, glass-roofed structures, and most commonly, farmers' crops. Rarely, massive hailstones have been known to cause concussions or fatal head trauma. Treatment of physical trauma is described here and in First aid. Sometimes, hail-producing clouds are identifiable by their green colouration. ^[5][6]

Short term detection

In the United States, to issue proper warnings and forecasts, National Weather Service uses a network of NEXRAD doppler radars to detect hail. The United States of America —commonly referred to as the NEXRAD or Nexrad ( Nex t-Generation Rad ar is a network of 158 high-resolution Doppler Weather radars operated by the National Weather Hail size and probability can be determined from radar data by a computer by different algorithms. This, in combination with an analysis of the radar display is an accurate way of detecting hail. An analysis of the radar data would include viewing reflectivity data at multiple angles above ground level to check for hail development in the upper levels of the storm, and checking the Vertically Integrated Liquid (VIL). VIL and hail do have a relationship, although it varies with atmospheric conditions and therefore is not highly accurate. Radar data can also be complimented by a knowledge of current atmospheric conditions which can allow one to determine if the current atmosphere is conducive to hail development.

Size scale

Hailstone size is often reported as compared to known objects rather than by reporting the actual diameter. Below is a table of commonly used objects for this purpose. ^[7] The UK organisation, TORRO, also scales for both hailstones and hailstorms. For the tornado scale developed by TORRO see TORRO scale. The Tornado and Storm Research Organisation (TORRO was founded by Terence Meaden ^[8]

Costly or deadly hailstorms

Hail clouds often exhibit a characteristic green coloration.

• Around the 9th century, several hundred pilgrims were killed by a massive hailstorm in Roopkund, Uttarakhand, India. A pilgrim is one who undertakes a Pilgrimage, literally 'far afield' WikipediaWikiProject Indian cities for details --> Roopkund is a place in Uttarakhand state of India, and it is the location of about three to Uttarakhand ( Hindi: उत्तराखण्ड or उत्तराखंड Uttar + Akhand i India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country ^[9]
• December 1967, A hailstorm hit Los Angeles County, blanketing the region much like a snowstorm. Los Angeles County is a county in California and is by far the most populous county in the United States. The storm also produced lightning, and one bolt struck an oil tank in Manhattan Beach, causing an explosion that covered much of the South Bay with the oil. Lightning is an atmospheric discharge of Electricity, which typically occurs during Thunderstorms and sometimes during volcanic eruptions or Manhattan Beach is a city located in southwestern Los Angeles County California, USA. The next hailstorm to hit the area was in 1979.
• July 11, 1990, Denver, Colorado, USA, Softball-sized hail destroyed roofs and cars, causing $625 million in total damage ($1 billion in damage adjusted to 2007 dollars ^[10]). Events 911 - Signing of the Treaty of Saint-Clair-sur-Epte between Charles the Simple and Rollo of Normandy. Year 1990 ( MCMXC) was a Common year starting on Monday (link displays the 1990 Gregorian calendar) The City and County of Denver (pronounced /ˈdɛnvɚ/ is the Capital and the most populous city of Colorado, in the United States The United States of America —commonly referred to as the
• September 7, 1991: a Labour Day thunderstorm caused $400 million worth of insurable damage in Calgary, Alberta, Canada. Events 1251 BC - A Solar eclipse on this date might mark the birth of legendary Heracles at Thebes Greece. Year 1991 ( MCMXCI) was a Common year starting on Tuesday (link will display full calendar of the Gregorian Calendar. Labour Day is an annual Holiday celebrated all over the world that resulted from efforts of Calgary (ˈkælgəriː is the largest city in the Province of Alberta, Canada Alberta (ælˈbɝtə is one of Canada's prairie provinces. It became a province on September 1 1905 Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page Thirteen additional hailstorms between 1981 and 1998 caused an estimated $600 million in damage in the Calgary area alone. ^[11][12]
• May 5, 1995, Dallas and Fort Worth, Texas, USA, $1. Events 553 - The Second Council of Constantinople begins 1215 - Rebel Barons renounce their allegiance to King John Year 1995 ( MCMXCV) was a Common year starting on Sunday. Events of 1995 Fort Worth is the fifth-largest city in the state of Texas and the seventeenth-largest city in the United States. The United States of America —commonly referred to as the 1 billion insured losses, total storm damage reported at around $2 billion. The storms produced hail about the size of softballs. ^[13][14][15]
• April 14, 1999, Sydney, New South Wales, Australia, $1. Events 43 BC - Battle of Forum Gallorum: Mark Antony, besieging Julius Caesar 's assassin Decimus Junius Brutus in Year 1999 ( MCMXCIX) was a Common year starting on Friday (link will display full 1999 Gregorian calendar) Sydney (ˈsɪdniː is the most populous city in Australia, with a Metropolitan area population of approximately 4 For a topic outline on this subject see List of basic Australia topics. 5 billion. 20,000 properties and 40,000 vehicles were damaged during the storm with more than 25 aircraft damaged at Sydney Airport, one person was killed while fishing after getting struck by lightning and several other people were injured. The 1999 Sydney hailstorm was the costliest Natural disaster in Australian Insurance history causing extensive damage along the east coast of New It was the costliest hailstorm to hit an Australian populated city. ^[16] Largest stone measured was 9. 5 cm. ^[17]
• March 29, 2000, The last known hail fatality in the United States occurs. Events 1461 - Wars of the Roses: Battle of Towton - Edward of York defeats Queen Margaret to become King 2000 ( MM) was a Leap year that started on Saturday of the Common Era, in accordance with the Gregorian calendar. The United States of America —commonly referred to as the The victim was Juan Oseguera, a nineteen-year-old man who died from head injuries after being hit by a softball sized hailstone in Lake Worth, Texas. Lake Worth is a city in Tarrant County, Texas, United States. ^[18]
• May 18, 2000, McHenry, Lake, northern Kane, and northern Cook County, Illinois, USA, $572 million ^[19]. Events 1152 - Henry II of England marries Eleanor of Aquitaine. 2000 ( MM) was a Leap year that started on Saturday of the Common Era, in accordance with the Gregorian calendar. McHenry County is located in the US state of Illinois. As of 2000 the population was 260077 Lake County is the farthest north-east County in the US state of Illinois. Kane County is located in the US state of Illinois. In 2000 the population of the County was 404119 Cook County is a county in the US state of Illinois. It is the second most populous county in the United States after Los Angeles The State of Illinois ( roughly ill-i-NOY is a state of the United States of America, the 21st to be admitted to the Union. The United States of America —commonly referred to as the Golfball-, baseball-, and softball-sized hail damaged roofs, cars, patio furniture, skylights, and windows in the area's worst and most widespread hailstorm in 30 years. Around 100,000 homes lost power. Hail was 3 inches (76 mm) deep in many areas. There were 100 canceled flights, and train service was disrupted. ^[20][21]
• April 10, 2001, St. Louis, Missouri, USA, $2. Events 879 - Louis III becomes King of the Western Franks. 1407 - the lama Year 2001 ( MMI) was a Common year starting on Monday according to the Gregorian calendar. Missouri ( or) is a state in the Midwestern region of the United States bordered by Iowa, Illinois, Kentucky, Tennessee The United States of America —commonly referred to as the 0 billion+. The costliest hailstorm in US history struck the I-70 corridor of eastern Kansas, across Missouri, into southwestern Illinois. The April 10-11 2001 tornado outbreak was a large tornado outbreak which affected the central Great Plains on April 10 - 11, 2001. The United States of America —commonly referred to as the Interstate 70 (I-70 is an Interstate highway in the United States that runs from Interstate 15 near Cove Fort Utah, to a Park and Ride ^[22]
• July 19, 2002, Henan Province, the People's Republic of China, 25 dead and hundreds injured. Events 711 - Muslim forces under Tariq ibn Ziyad defeat the Visigoths led by their king Roderic. See also 2002 (disambiguation Year 2002 ( MMII) was a Common year starting on Tuesday of the Gregorian calendar. Henan ( is a province of the People's Republic of China, located in the central part of the country Talk People's Republic of China) PEOPLE'S REPUBLIC OF CHINA ARTICLE GUIDELINES
• The largest hailstone on record fell on June 22, 2003 in Aurora, Nebraska, USA. Events 217 BC - Battle of Raphia: Ptolemy IV of Egypt defeats Antiochus III the Great of the Seleucid kingdom. Year 2003 ( MMIII) was a Common year starting on Wednesday of the Gregorian calendar. Aurora is a city in Hamilton County, Nebraska in the United States of America. The United States of America —commonly referred to as the It has a 7-inch (180 mm) diameter and a circumference of 18. 75 inches (476 mm).
• April 20 – April 21, 2006, San Marcos, Texas, USA, hail of sizes up to 10 cm^[23][24] results in 10,000 auto claims, 7,000 homeowner and commercial property claims ranging between $100-160 million insured losses. Events 1303 - The University of Rome La Sapienza is instituted by Pope Boniface VIII. Events 753 BC - Romulus and Remus found Rome ( traditional date) Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. San Marcos is a city in the US state of Texas, and is the county seat of Hays County. The United States of America —commonly referred to as the ^[25][26] One woman was hospitalized. ^[27] The storm was especially costly at the San Marcos Outlet Malls and a nearby Toyota dealership. The San Marcos Outlet Malls are two discrete Outlet malls the Prime Outlets and Tanger Factory Outlet Center, and are located on Interstate Highway (pronounced) is a Multinational corporation headquartered in Japan, and is currently the world's largest Automaker. ^[28][29]
• June 28 – June 29, 2006, Villingen-Schwenningen and suburbs, Baden-Württemberg, Germany, supercell thunderstorms, severe damage by very large hailstones (softball-size), causing € 150 million damage, more than 100 fatalities. Events 1098 - Fighters of the First Crusade defeat Kerbogha of Mosul. Events 512 - A Solar eclipse is recorded by a monastic chronicler in Ireland. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Villingen-Schwenningen is the largest city of the Schwarzwald-Baar district located in the south of Baden-Württemberg, Germany. Baden-Württemberg is one of the 16 states ( Bundesländer) of the Federal Republic of Germany. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. A supercell is a severe thunderstorm with a deep continuously rotating updraft (a Mesocyclone)
• December 9, 2007, Sydney, New South Wales, Australia, Severe thunderstorms caused immense damage in the North and Western Suburbs of Sydney. Events 536 - Byzantine General Belisarius enters Rome while the Ostrogothic garrison peacefully leaves the city Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Sydney (ˈsɪdniː is the most populous city in Australia, with a Metropolitan area population of approximately 4 For a topic outline on this subject see List of basic Australia topics. Worst hit were the suburbs of Blacktown, Castle Hill and neighbouring Baulkham Hills. Blacktown is a Suburb in the City of Blacktown, in Western Sydney, in the state of New South Wales, Australia. Castle Hill is a Suburb in the north-west of Sydney, in the state of New South Wales, Australia. Baulkham Hills is a Suburb in the north-west of Sydney, in the state of New South Wales, Australia. Hail stones the size of golf balls damaged cars, windows and homes. Largest hail stones reached almost 10 cm in diameter in Kings Langley. ^[30]

See also

• Sleet
• Graupel
• Snow grains
• Hail cannon

References

Further reading

• Rogers and Yau (1989). The National Oceanic and Atmospheric Administration ( NOAA) is a scientific agency within the United States Department of Commerce focused on the conditions of the A Short Course in CLOUD PHYSICS. Massachusetts: Butterworth-Heinemann. ISBN 0-7506-3215-1.  
• Jim Mezzanotte (2007). Hailstorms. Gareth Stevens Publishing. ISBN 978-0836879124.  
• Snowden Dwight Flora (2003). Hailstorms of the United States. Textbook Publishers. ISBN 978-0758116987.  
• Narayan R. Gokhale (1974). Hailstorms and Hailstone Growth. State University of New York Press. ISBN 978-0873953139.  
• Duncan Scheff (2001). Ice and Hailstorms. Raintree Publishers. ISBN 978-0739847039.  

External links

• Hail Research Information Center
• Images of hail and hailstorms
• Images of a major giant hail event in Brazil
• Hail factsheet
• Using sound to break up hail
• Youtube Video of large hailstorm in progress
• Social & Economic Costs of Hail from "NOAA Socioeconomics" website initiative