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Cyclone Elaine
Severe Tropical Cyclone Elaine was a severe tropical cyclone which formed in the 1998–99 Australian region cyclone season. Elaine, along with Cyclone Vance, both made landfall and caused destruction in Western Australia. Elaine had made landfall on 20 March, while Vance made landfall on 23 March. Elaine formed after a monsoon trough, which spawned an area of low-pressure on 12 March. The low moved west into a favourable environment and intensified into Tropical Cyclone Elaine on 15 March. 24 hours later, on 16 March, Elaine attained severe tropical cyclone status. Two days later, Elaine reached its peak of . Thereafter, the storm entered a period of weakening. On 20 March, Elaine was downgraded to a tropical cyclone. Elaine made landfall over Western Australia with winds. More than 1,000 people were evacuated from the areas of impact. Elaine degenerated into a remnant low, a few hours after impact. Meteorological history A monsoon trough had formed from a monsoon on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Australia
Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Australia is Australia's largest state, with a total land area of . It is the second-largest country subdivision in the world, surpassed only by Russia's Sakha Republic. the state has 2.76 million inhabitants percent of the national total. The vast majority (92 percent) live in the south-west corner; 79 percent of the population lives in the Perth area, leaving the remainder of the state sparsely populated. The first Europeans to visit Western Australia belonged to the Dutch Dirk Hartog expedition, who visited the Western Australian coast in 1616. The first permanent European colony of Western Australia occurred following the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monsoon
A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal oscillation of the Intertropical Convergence Zone (ITCZ) between its limits to the north and south of the equator. Usually, the term monsoon is used to refer to the rainy phase of a seasonally changing pattern, although technically there is also a dry phase. The term is also sometimes used to describe locally heavy but short-term rains. The major monsoon systems of the world consist of the West African, Asia–Australian, the North American, and South American monsoons. The term was first used in English in British India and neighboring countries to refer to the big seasonal winds blowing from the Bay of Bengal and Arabian Sea in the southwest bringing heavy rainfall to the area. Etymology The etymology of the word monsoon is not wholl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclone Emma (2006)
Tropical Cyclone Emma was a weak but unusually large tropical cyclone that affected a substantial portion of Western Australia during the 2005–06 Australian region cyclone season. Forming out of an area of low pressure on 25 February, the precursor to Emma slowly tracked southward. Although classified tropical, the structure of the system represented that of a monsoonal storm. However, low wind shear and well-developed outflow gradually allowed convection to develop near the centre of circulation. As the system approached the Pilbara coastline of Western Australia on 27 February, it intensified into a Category 1 cyclone and attained peak 10-minute sustained winds of . After moving inland near Mardie, Emma weakened to a tropical low but became exceedingly large; its cloud cover obscured most of Western Australia. The remnants of the weak storm persisted until 1 March, at which time they dissipated over the Great Australian Bight. Although a weak storm, rainfall from Emma caus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post-tropical Cyclone
A post-tropical cyclone is a former tropical cyclone that no longer possesses enough tropical qualities to be considered a tropical cyclone. The word may refer to a former tropical cyclone undergoing extratropical transition or a tropical cyclone degenerating into a remnant low. A tropical cyclone degenerating into a trough or wave, or having it's low level circulation dissipate overland, lacks a cyclonic circulation and is referred as remnants instead of a post-tropical cyclone. However, post-tropical cyclones or remnants can continue producing high winds and heavy rains. Classification Classes Two classes of post-tropical cyclones exist * Extratropical cyclone, which is frontal, sometimes still retains winds of hurricane or tropical storm force. Hurricane Paulette (2020) provides a recent example of an extratropical cyclone, in which it no longer has a warm core in higher latitudes when it was over Nova Scotia and all points north in its trajectory. * Remnant low, which is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eye (cyclone)
The eye is a region of mostly calm weather at the center of tropical cyclones. The eye of a storm is a roughly circular area, typically in diameter. It is surrounded by the ''eyewall'', a ring of towering thunderstorms where the most severe weather and highest winds occur. The cyclone's lowest barometric pressure occurs in the eye and can be as much as 15 percent lower than the pressure outside the storm. In strong tropical cyclones, the eye is characterized by light winds and clear skies, surrounded on all sides by a towering, symmetric eyewall. In weaker tropical cyclones, the eye is less well defined and can be covered by the central dense overcast, an area of high, thick clouds that show up brightly on satellite imagery. Weaker or disorganized storms may also feature an eyewall that does not completely encircle the eye or have an eye that features heavy rain. In all storms, however, the eye is the location of the storm's minimum barometric pressure—where the atmospheric pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rapid Intensification
In meteorology, rapid intensification is a situation where a tropical cyclone intensifies dramatically in a short period of time. The United States National Hurricane Center defines rapid intensification as an increase in the maximum sustained winds of a tropical cyclone of at least in a 24-hour period. Necessary conditions External In order for rapid intensification to occur, several conditions must be in place. Water temperatures must be extremely warm (near or above ), and water of this temperature must be sufficiently deep such that waves do not churn deeper cooler waters up to the surface. Wind shear must be low; when wind shear is high, the convection and circulation in the cyclone will be disrupted. Dry air can also limit the strengthening of tropical cyclones. Internal Usually, an anticyclone in the upper layers of the troposphere above the storm must also be present for extremely low surface pressures to develop. This is because air must be converging towards the low ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outflow (meteorology)
Outflow, in meteorology, is air that flows outwards from a storm system. It is associated with ridging, or anticyclonic flow. In the low levels of the troposphere, outflow radiates from thunderstorms in the form of a wedge of rain-cooled air, which is visible as a thin rope-like cloud on weather satellite imagery or a fine line on weather radar imagery. For observers on the ground, a thunderstorm outflow boundary often approaches in otherwise clear skies as a low, thick cloud that brings with it a gust front. Low-level outflow boundaries can disrupt the center of small tropical cyclones. However, outflow aloft is essential for the strengthening of a tropical cyclone. If this outflow is restricted or undercut, the tropical cyclone weakens. If two tropical cyclones are in close proximity, the upper-level outflow from the upwind system can limit the development of the other system. Thunderstorms For thunderstorms, outflow tends to indicate the development of a system. Large quan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Shear
Wind shear (or windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizontal wind shear. Vertical wind shear is a change in wind speed or direction with a change in altitude. Horizontal wind shear is a change in wind speed with a change in lateral position for a given altitude. Wind shear is a microscale meteorological phenomenon occurring over a very small distance, but it can be associated with mesoscale or synoptic scale weather features such as squall lines and cold fronts. It is commonly observed near microbursts and downbursts caused by thunderstorms, fronts, areas of locally higher low-level winds referred to as low-level jets, near mountains, radiation inversions that occur due to clear skies and calm winds, buildings, wind turbines, and sailboats. Wind shear has significant effects on the control of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bureau Of Meteorology
The Bureau of Meteorology (BOM or BoM) is an executive agency of the Australian Government responsible for providing weather services to Australia and surrounding areas. It was established in 1906 under the Meteorology Act, and brought together the state meteorological services that existed before then. The states officially transferred their weather recording responsibilities to the Bureau of Meteorology on 1 January 1908. History The Bureau of Meteorology was established on 1 January 1908 following the passage of the ''Meteorology Act 1906''. Prior to Federation in 1901, each colony had had its own meteorological service, with all but two colonies also having a subsection devoted to astronomy. In August 1905, federal home affairs minister Littleton Groom surveyed state governments for their willingness to cede control, finding South Australia and Victoria unwilling. However, at a ministerial conference in April 1906 the state governments agreed to transfer responsibility for m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low-pressure Area
In meteorology, a low-pressure area, low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. Low-pressure areas are commonly associated with inclement weather (such as cloudy, windy, with possible rain or storms), while high-pressure areas are associated with lighter winds and clear skies. Winds circle anti-clockwise around lows in the northern hemisphere, and clockwise in the southern hemisphere, due to opposing Coriolis force, Coriolis forces. Low-pressure systems form under areas of wind divergence that occur in the upper levels of the Atmosphere of Earth, atmosphere (aloft). The formation process of a low-pressure area is known as cyclogenesis. In Meteorology#Dynamic meteorology, meteorology, atmospheric divergence aloft occurs in two kinds of places: * The first is in the area on the east side of upper Trough (meteorology), troughs, which form half of a Rossby wave within the Westerlies (a trough (meteorology), trough with la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post-tropical Cyclone
A post-tropical cyclone is a former tropical cyclone that no longer possesses enough tropical qualities to be considered a tropical cyclone. The word may refer to a former tropical cyclone undergoing extratropical transition or a tropical cyclone degenerating into a remnant low. A tropical cyclone degenerating into a trough or wave, or having it's low level circulation dissipate overland, lacks a cyclonic circulation and is referred as remnants instead of a post-tropical cyclone. However, post-tropical cyclones or remnants can continue producing high winds and heavy rains. Classification Classes Two classes of post-tropical cyclones exist * Extratropical cyclone, which is frontal, sometimes still retains winds of hurricane or tropical storm force. Hurricane Paulette (2020) provides a recent example of an extratropical cyclone, in which it no longer has a warm core in higher latitudes when it was over Nova Scotia and all points north in its trajectory. * Remnant low, which is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moora, Western Australia
Moora is a townsite located 177 km north of Perth in the Wheatbelt region of Western Australia. Moora was one of the original stations on the Midland railway line to Walkaway, and the townsite was gazetted in 1895. At the , Moora had a population of 1,755. Commercial area The town is the largest wheat belt town between Geraldton and Perth. The town provides facilities and services such as commercial banks, schools, commerce and retail sectors, community recreational facilities; plus a Pharmacy, Dentist, Doctors and District Hospital. The surrounding areas produce wheat and other cereal crops. The town is a receival site for Cooperative Bulk Handling. Natural disasters The town was left underwater in 1932 when heavy rainfall inundated the town, causing severe flooding. The town was left isolated as both rail lines and roads had portions washed away. Over half the town was submerged to a depth of , and once the waters receded, was left under a thick coating of mud. Crops ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
