A rainband is a cloud and precipitation structure associated with an area of rainfall which is significantly elongated. Rainbands can be stratiform or convective, and are generated by differences in temperature. When noted on weather radar imagery, this precipitation elongation is referred to as banded structure. Rainbands within tropical cyclones are curved in orientation. Tropical cyclone rainbands contain showers and thunderstorms that, together with the eyewall and the eye, constitute a hurricane or tropical storm. The extent of rainbands around a tropical cyclone can help determine the cyclone's intensity.
Rainbands spawned near and ahead of cold fronts can be squall lines which are able to produce tornadoes. Rainbands associated with cold fronts can be warped by mountain barriers perpendicular to the front's orientation due to the formation of a low-level barrier jet. Bands of thunderstorms can form with sea breeze and land breeze boundaries, if enough moisture is present. If sea breeze rainbands become active enough just ahead of a cold front, they can mask the location of the cold front itself. Banding within the comma head precipitation pattern of an extratropical cyclone can yield significant amounts of rain or snow. Behind extratropical cyclones, rainbands can form downwind of relative warm bodies of water such as the Great Lakes. If the atmosphere is cold enough, these rainbands can yield heavy snow.
Rainbands in advance of warm occluded fronts and warm fronts are associated with weak upward motion, and tend to be wide and stratiform in nature. In an atmosphere with rich low level moisture and vertical wind shear, narrow, convective rainbands known as squall lines generally in the cyclone's warm sector, ahead of strong cold fronts associated with extratropical cyclones. Wider rain bands can occur behind cold fronts, which tend to have more stratiform, and less convective, precipitation. Within the cold sector north to northwest of a cyclone center, in colder cyclones, small scale, or mesoscale, bands of heavy snow can occur within a cyclone's comma head precipitation pattern with a width of 32 kilometres (20 mi) to 80 kilometres (50 mi). These bands in the comma head are associated with areas of frontogensis, or zones of strengthening temperature contrast. Southwest of extratropical cyclones, curved flow bringing cold air across the relatively warm Great Lakes can lead to narrow lake effect snow bands which bring significant localized snowfall.
Rainbands exist in the periphery of tropical cyclones, which point towards the cyclone's center of low pressure. Rainbands within tropical cyclones require ample moisture and a low level pool of cooler air. Bands located 80 kilometres (50 mi) to 150 kilometres (93 mi) from a cyclone's center migrate outward. They are capable of producing heavy rains and squalls of wind, as well as tornadoes, particularly in the storm's right-front quadrant.
Some rainbands move closer to the center, forming a secondary, or outer, eyewall within intense hurricanes. Spiral rainbands are such a basic structure to a tropical cyclone that in most tropical cyclone basins, use of the satellite-based Dvorak technique is the primary method used to determine a tropical cyclone's maximum sustained winds. Within this method, the extent of spiral banding and difference in temperature between the eye and eyewall is used to assign a maximum sustained wind and a central pressure. Central pressure values for their centers of low pressure derived from this technique are approximate.
Different programs have been studying these rainbands, including the Hurricane Rainband and Intensity Change Experiment.
Convective rainbands can form parallel to terrain on its windward side, due to lee waves triggered by hills just upstream of the cloud's formation. Their spacing is normally 5 kilometres (3.1 mi) to 10 kilometres (6.2 mi) apart. When bands of precipitation near frontal zones approach steep topography, a low-level barrier jet stream forms parallel to and just prior to the mountain ridge, which slows down the frontal rainband just prior to the mountain barrier. If enough moisture is present, sea breeze and land breeze fronts can form convective rainbands. Sea breeze front thunderstorm lines can become strong enough to mask the location of an approaching cold front by evening. The edge of ocean currents can lead to the development of thunderstorm bands due to heat differential at this interface. Downwind of islands, bands of showers and thunderstorms can develop due to low level wind convergence downwind of the island edges. Offshore California, this has been noted in the wake of cold fronts.
The 1900 Western Australian floods were a series of flooding events from March to May 1900 that affected large areas of Western Australia, primarily in the Pilbara and Gascoyne regions, though it extended to cover most of the state except the more humid Kimberley and South West regions.
The flooding had its beginnings in heavy rain in March 1900 over a very broad area extending from North West Cape to the southeastern corner of the state. It was in the middle of April over the Easter long weekend, however, that flooding began in earnest, and at the end of the month the majority of the normally arid parts of the state were completely inundated: by Easter Monday, all houses in Roebourne were completely surrounded by water from the Harding River.During April and May, the rain was associated with what was described in the press of the time as "a gentle easterly flow" but today is recognised to be a northwest cloudband. There were several of these cloudbands during the month, and the result was some astonishing rainfall totals, for instance Wiluna received 527.1 millimetres (20.8 in) and Cossack (near Port Hedland) as much as 636.4 millimetres (25.1 in). The heaviest rainfall of all occurred in the Pilbara during the middle of the month, and resulted in rivers such as the Gascoyne, Ashburton and Murchison overflowing their banks for extraordinarily sustained periods. (Unfortunately, there were no gauges at the time so we do not know what the exact heights were).
So heavy indeed was the rainfall that the normally arid "North West" (as the region was known at the time) was completely boggy and the primitive horse-drawn carts could not traverse the country not only in April, but well into May, especially as another major rainband affected the State early that month, with Onslow recording as much as 9.31 inches (236 mm) in a day on the third. The busy Easter mail services were most severely hit of all, with the mail vans from Perth bogged down at Peak Hill after crossing a Gascoyne River that was supposedly 3 miles (4.8 km) wide as the rain extended at the end of Easter to the Murchison River’s basin.Wash-outs on the telegraph line with which the remote regions affected by the floods communicated with Perth were indeed not repaired until well into June, a month after flooding peaked in the Pilbara and Gascoyne and had spread eastward to the goldfields of Western Australia. In the interim, communication about the flooding was delayed almost uniformly by at least three or four days, aided by a severe famine and shortage of food for pack horses and salt lakes in the Goldfields such as Lake Carnegie and Lake Maitland filled for probably the only time in centuries - they were never seen with any water between the first European settlement of Western Australia and these floods were thus unprecedented for an extremely long period of time.1988–89 South Pacific cyclone season
The 1988–89 South Pacific cyclone season was an active tropical cyclone season with an above average number of tropical cyclones observed.Bar (tropical cyclone)
The bar of a mature tropical cyclone is a very dark gray-black layer of cloud appearing near the horizon as seen from an observer preceding the approach of the storm, and is composed of dense stratocumulus clouds. Cumulus and cumulonimbus clouds bearing precipitation follow immediately after the passage of the wall-like bar. Altostratus, cirrostratus and cirrus clouds are usually visible in ascending order above the top of the bar, while the wind direction for an observer facing toward the bar is typically from the left and slightly behind the observer.Cumulus congestus cloud
Cumulus congestus clouds, also known as towering cumulus, are a form of cumulus cloud that can be based in the low or middle height ranges. They achieve considerable vertical development in areas of deep, moist convection. They are an intermediate stage between cumulus mediocris and cumulonimbus.Effects of Hurricane Dennis in Georgia
The effects of Hurricane Dennis in Georgia included two deaths and $24 million (2005 USD) in damage. On June 29, 2005, a tropical wave emerged off the west coast of Africa. Gradually, the system organized on July 2 and formed a broad low pressure area. The system continued to organize, and it became a tropical depression on July 4. Tracking westward, it became a tropical storm on July 5 and a hurricane on July 7. Dennis rapidly intensified to attain Category 4 status on the Saffir-Simpson Hurricane Scale before making landfall on Cuba. The storm weakened to Category 1 status before re-emerging in the Gulf of Mexico and intensifying. Dennis made landfall on the Florida Panhandle on July 10, then tracked over southeast Alabama.
Dennis had moderate effects in the state, primarily from flooding. One rainband in particular stalled in southwest portions of the state and produced 4–8 inches (100–200 mm) of rain, with isolated reports of up to 12 inches (300 mm). Flash flooding occurred in several areas, damaging hundreds of homes and businesses. Light to moderate wind gusts of 42 miles per hour (68 km/h) combined with saturated ground downed several trees, one of which fell into a house, killing a man near Atlanta. A man also died while working with utility crews to restore power. One tornado was reported, downing 200 trees.Hurricane Daniel (2006)
Hurricane Daniel was the second strongest hurricane of the 2006 Pacific hurricane season. The fourth named storm of the season, Daniel originated on July 16 from a tropical wave off the coast of Mexico. It tracked westward, intensifying steadily to reach peak winds of 150 mph (240 km/h) on July 22. At the time, the characteristics of the cyclone resembled those of an annular hurricane. Daniel gradually weakened as it entered an area of cooler water temperatures and increased wind shear, and after crossing into the Central Pacific Ocean, it quickly degenerated into a remnant low-pressure area on July 26, before dissipating two days later.
Initial predictions suggested that the cyclone would pass through the Hawaiian Islands as a tropical storm; however, Daniel's remnants dissipated southeast of Hawaii. The storm brought light to moderate precipitation to the Island of Hawaii and Maui, causing minor flooding, although no major damage or fatalities were reported.Hurricane Florence (1988)
Hurricane Florence was the third of four named tropical cyclones to make landfall on the United States during the 1988 Atlantic hurricane season. The seventh tropical storm and second hurricane of the season, Florence developed on September 7 from an area of convection associated with a dissipating frontal trough in the southern Gulf of Mexico. After initially moving eastward, the storm turned northward and strengthened. Florence reached hurricane status and later peak winds of 80 mph (130 km/h) on September 9 shortly before striking southeastern Louisiana. The storm rapidly weakened over land and dissipated on September 11 over northeastern Texas.
Early in its duration, the storm dropped rainfall across the Yucatán Peninsula. Upon striking Louisiana, Florence produced a moderate storm surge, causing severe beach erosion in some locations. Gusty winds were also reported, causing power outages to over 100,000 people. In Alabama, one man died while trying to secure his boat. Rainfall from the hurricane caused severe river flooding in portions of the Florida Panhandle in an area already severely affected by heavy rainfall; the flooding damaged or destroyed dozens of houses in Santa Rosa County. Throughout its path, damage totaled about $2.9 million (1988 USD, $5.3 million 2008 USD).John Browning (scientific instrument maker)
John Browning (c.1831 – 1925) was an English inventor and manufacturer of precision scientific instruments in the 19th and early 20th centuries. He hailed from a long line of English instrument makers and transformed the family business from one dealing in nautical instruments to one specialising in scientific instruments. Browning was particularly well known for his advances in the fields of spectroscopy, astronomy, and optometry.John Rand Capron
John Rand Capron (1829–1888) was an English amateur scientist, astronomer and photographer. Though a solicitor by profession, he became an expert on spectroscopy, particularly in relation to the aurora, and published many articles during his lifetime.He is also remembered for a speculative letter, in the scientific journal Nature on early incidences of "crop circles", in which he suggested they were caused by "cyclonic wind action".Landfall
Landfall is the event of a storm or waterspout moving over land after being over water.Patos
Patos is a municipality in the state of Paraíba in the Northeast Region of Brazil.
Its population is 104,716 inhabitants (IBGE, 2013).
Esporte and Nacional are the city's two football (soccer) clubs. They play at the José Cavalcanti Municipal Stadium. There are four multisport arenas: Rivaldão, AABB, SESC and SESI.Sahel drought
The Sahel has long experienced a series of historic droughts, dating back to at least the 17th century. The Sahel region is a climate zone sandwiched between the African Savannah grasslands to the south and the Sahara desert to the north, across West and Central Africa. While the frequency of drought in the region is thought to have increased from the end of the 19th century, three long droughts have had dramatic environmental and societal effects upon the Sahel nations. Famine followed severe droughts in the 1910s, the 1940s, and the 1960s, 1970s and 1980s, although a partial recovery occurred from 1975-80. The most recent drought occurred in 2012.
While at least one particularly severe drought has been confirmed each century since the 17th century, the frequency and severity of recent Sahelian droughts stands out. Famine and dislocation on a massive scale—from 1968 to 1974 and again in the early and mid-1980s—was blamed on two spikes in the severity of the 1960-1980s drought period. From the late 1960s to early 1980s famine killed 100,000 people, left 750,000 dependent on food aid, and affected most of the Sahel's 50 million people. The economies, agriculture, livestock and human populations of much of Mauritania, Mali, Chad, Niger and Burkina Faso (known as Upper Volta during the time of the drought) were severely impacted. As disruptive as the droughts of the late 20th century were, evidence of past droughts recorded in Ghanaian lake sediments suggest that multi-decadal megadroughts were common in West Africa over the past 3,000 years and that several droughts lasted far longer and were far more severe.Since the 1980s, summer rainfall in the Sahel has been increasing; this has been associated with an increase in vegetation, forming what has been called a 'greening' of the Sahel. The observed increase in rainfall is accounted for by enhancements in the African easterly jet, which is known to induce wet anomalies. A 2011 study found that the positional shifts in the African easterly jet and African easterly waves accompanied the northward migration of the Sahel rainband.Snowsquall
A snowsquall (or snow squall) is a sudden moderately heavy snow fall with blowing snow and strong, gusty surface winds. It is often referred to as a whiteout and is similar to a blizzard but is localized in time or in location and snow accumulations may or may not be significant.Squall line
A squall line or quasi-linear convective system (QLCS) is a line of thunderstorms forming along or ahead of a cold front. In the early 20th century, the term was used as a synonym for cold front. It contains heavy precipitation, hail, frequent lightning, strong straight-line winds, and possibly tornadoes and waterspouts. Strong straight-line winds can occur where the squall line is in the shape of a bow echo. Tornadoes can occur along waves within a line echo wave pattern (LEWP), where mesoscale low-pressure areas are present. Some bow echoes which develop within the summer season are known as derechos, and they move quite fast through large sections of territory. On the back edge of the rainband associated with mature squall lines, a wake low can be present, sometimes associated with a heat burst.The Hurricane Rainband and Intensity Change Experiment
The Hurricane Rainband and Intensity Change Experiment (RAINEX) is a project to improve hurricane intensity forecasting via measuring interactions between rainbands and the eyewalls of tropical cyclones. The experiment was planned for the 2005 Atlantic hurricane season. This coincidence of RAINEX with the 2005 Atlantic hurricane season led to the study and exploration of infamous hurricanes Katrina, Ophelia, and Rita. Where Hurricane Katrina and Hurricane Rita would go on to cause major damage to the US Gulf coast, Hurricane Ophelia provided an interesting contrast to these powerful cyclones as it never developed greater than a category 1.
The RAINEX project was a collaboration between the University of Miami (UM), Rosenstiel School of Marine and Atmospheric Science (RSMAS), The University of Washington, Department of Atmospheric Sciences, The National Oceanic and Atmospheric Administration (NOAA) and the US Navy, Office of Naval Research.
The objective of the research was to study the mechanism by which hurricane eyewall replacement cycle occurs. Luckily for the sake of the research, one such case of eyewall replacement occurred during the study of Hurricane Rita. In tropical cyclones maximum wind speed of the storm, which occurs at the eyewall, is a primary indicator of its overall strength which is important in predicting overall intensity. Just beyond this eyewall is a moat which separates the inner rainbands (eventually the outer eyewall) from the (inner) eyewall. Better understanding the dynamics of this region before, and during eyewall replacement could aid in better intensity predictions.The Rainband
The Rainband are a five-piece indie rock band from Manchester, England founded in 2010 by lead singer Martin Finnigan and guitarist Phil Rainey – who made his name with Peter Hook’s cult combo Monaco (band). Finnigan and Rainey were joined by drummer Steve Irlam (replaced by James Cowell in 2015) and bassist Paul Daggatt later that year. In 2012 Paul Daggatt left and was replaced by Joe Wilson, who then moved onto guitar while his brother Sam Wilson took on bass.
To this day The Rainband have released three original studio EP's (‘The Prodigal EP’, 'Fire EP' and 'Sirens EP') and several singles. Their single ‘Rise Again’, a tribute to legendary MotoGP rider Marco Simoncelli, entered the UK Independent Charts at No.9 and remained in the Virgin Radio Italian charts during fourteen weeks, peaking at No.5. Double Superbike world champion James Toseland played the piano on the track and joined The Rainband on stage in Norwich and at the MotoGP in Silverstone in support of the project in aid of the Marco Simoncelli Foundation. Martin Finnigan is currently ambassador for the Simoncelli Foundation in the UK.
The band made their debut at Glastonbury Festival in June 2013 on one of the main stages. Their past live performances include supports for Simple Minds, Kaiser Chiefs and Ocean Colour Scene. In July 2014 The Rainband were Special Guests of Scottish singer-songwriter Paolo Nutini at Goa-Boa Festival in Genova, Hydrogen Live (Piazzola Sul Brenta, Padova) and Rock in Roma where they had supported Simple Minds in 2012. Rolling Stone featured them extensively following their performances as Nutini's support.Thunderstorm
A thunderstorm, also known as an electrical storm or a lightning storm, is a storm characterized by the presence of lightning and its acoustic effect on the Earth's atmosphere, known as thunder. Relatively weak thunderstorms are sometimes called thundershowers. Thunderstorms occur in a type of cloud known as a cumulonimbus. They are usually accompanied by strong winds, and often produce heavy rain and sometimes snow, sleet, or hail, but some thunderstorms produce little precipitation or no precipitation at all. Thunderstorms may line up in a series or become a rainband, known as a squall line. Strong or severe thunderstorms include some of the most dangerous weather phenomena, including large hail, strong winds, and tornadoes. Some of the most persistent severe thunderstorms, known as supercells, rotate as do cyclones. While most thunderstorms move with the mean wind flow through the layer of the troposphere that they occupy, vertical wind shear sometimes causes a deviation in their course at a right angle to the wind shear direction.
Thunderstorms result from the rapid upward movement of warm, moist air, sometimes along a front. As the warm, moist air moves upward, it cools, condenses, and forms a cumulonimbus cloud that can reach heights of over 20 kilometres (12 mi). As the rising air reaches its dew point temperature, water vapor condenses into water droplets or ice, reducing pressure locally within the thunderstorm cell. Any precipitation falls the long distance through the clouds towards the Earth's surface. As the droplets fall, they collide with other droplets and become larger. The falling droplets create a downdraft as it pulls cold air with it, and this cold air spreads out at the Earth's surface, occasionally causing strong winds that are commonly associated with thunderstorms.
Thunderstorms can form and develop in any geographic location but most frequently within the mid-latitude, where warm, moist air from tropical latitudes collides with cooler air from polar latitudes. Thunderstorms are responsible for the development and formation of many severe weather phenomena. Thunderstorms, and the phenomena that occur along with them, pose great hazards. Damage that results from thunderstorms is mainly inflicted by downburst winds, large hailstones, and flash flooding caused by heavy precipitation. Stronger thunderstorm cells are capable of producing tornadoes and waterspouts.
There are four types of thunderstorms: single-cell, multi-cell cluster, multi-cell lines and supercells. Supercell thunderstorms are the strongest and most severe. Mesoscale convective systems formed by favorable vertical wind shear within the tropics and subtropics can be responsible for the development of hurricanes. Dry thunderstorms, with no precipitation, can cause the outbreak of wildfires from the heat generated from the cloud-to-ground lightning that accompanies them. Several means are used to study thunderstorms: weather radar, weather stations, and video photography. Past civilizations held various myths concerning thunderstorms and their development as late as the 18th century. Beyond the Earth's atmosphere, thunderstorms have also been observed on the planets of Jupiter, Saturn, Neptune, and, probably, Venus.Tropical Storm Danielle (1986)
Tropical Storm Danielle was the only tropical storm to move through the Caribbean Sea in 1986. A short-lived cyclone, Danielle developed on September 7 to the east of the southern Lesser Antilles. Strengthening to peak winds of 60 mph (95 km/h), the storm moved through Saint Vincent and the Grenadines, where a rainband moved across the main island with hurricane-force gusts. Continuing westward, Danielle absorbed dry air from northern South America and dissipated on September 10.
The threat of Danielle prompted gale warnings in Barbados as well as Saint Vincent and the Grenadines. On the former island, wind gusts reached 40 mph (64 km/h). On Saint Vincent, the winds caused a major power outage, while heavy rainfall left crop damage. Another rain system affected the country a few weeks later, and the combined monetary damage totaled $9.2 million (1986 USD, $18 million 2010 USD); 142 people had to seek shelter after their homes were destroyed, and a total of 436 dwellings were impacted to some degree. In Trinidad and Tobago, the outer rainbands produced flooding and mudslides. Further west, Danielle briefly threatened Jamaica, although it dissipated before affecting the island.Typhoon Isa
Typhoon Isa was the first of eleven super-typhoons to occur during the 1997 Pacific typhoon season. The second tropical cyclone of the season, Isa developed from a disturbance in the monsoon trough near the Caroline Islands on April 12. It moved erratically at first, though after attaining tropical storm status it curved westward due to the subtropical ridge to its north. Isa very gradually intensified, and on April 20 the typhoon reached peak 1-min winds of 270 km/h (165 mph), as reported by the Joint Typhoon Warning Center; Japan Meteorological Agency reported maximum 10-min winds of 155 km/h (100 mph). After turning northward, it accelerated to the northeast, and merged with a larger extratropical cyclone on April 24.
Early in its duration, Isa caused light rainfall and moderate winds on Pohnpei. Later, a stationary rainband from the typhoon dropped heavy precipitation on Guam during its dry season. Damage in the Guam National Weather Service area of responsibility totaled $1 million (1997 USD, $1.56 million 2019 USD), the majority of it from crop damage. No deaths were reported.