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.
A supercell is a thunderstorm characterized by the presence of a mesocyclone, a deep, persistently rotating updraft. Due to this, these storms are sometimes referred to as rotating thunderstorms. Of the four classifications of thunderstorms, supercells are the overall least common and have the potential to be the most severe. Supercells are often isolated from other thunderstorms, and can dominate the local weather up to 32 kilometres (20 mi) away. They tend to last 2–4 hours.
A severe thunderstorm warning is a type of public warning for severe weather that is issued by weather forecasting agencies worldwide when one or more severe thunderstorms have been detected by Doppler weather radar, observed by weather spotters, or reported by an emergency management agency, law enforcement, or the general public. Unlike a watch, a warning is issued to areas in the direct path of active severe thunderstorms, that are expecting a direct impact typically within an hour. Severe thunderstorms can cause property damage and injury due to large hail, high winds, and flooding due to torrential rainfall. The exact criteria to issue a warning varies from country to country.
Severe storms in Australia refers to the storms, including cyclones, which have caused severe damage in Australia.
Tropical Storm Bill was a tropical storm that affected the Gulf Coast of the United States in the summer of 2003. The second storm of the 2003 Atlantic hurricane season, Bill developed from a tropical wave on June 29 to the north of the Yucatán Peninsula. It slowly organized as it moved northward, and reached a peak of 60 miles per hour (97 km/h) shortly before making landfall in south-central Louisiana. Bill quickly weakened over land, and as it accelerated to the northeast, moisture from the storm, combined with cold air from an approaching cold front, produced an outbreak of 34 tornadoes. Bill became extratropical on July 2, and was absorbed by the cold front later that day.
Severe Tropical Cyclone Vance was a tropical cyclone that struck Western Australia during the active 1998–99 Australian region cyclone season, and was also one of six tropical cyclones to form off the coast of Australia during that season. When making landfall the Learmonth Meteorological Office recorded the highest Australian wind gust of 267 km/h (166 mph). The previous highest gust was 259 km/h (161 mph) at nearby Mardie during Cyclone Trixie. This record was surpassed in 2010 after a world record wind-gust of 408 km/h (254 mph) at Barrow Island during Cyclone Olivia in 1996 was declared official by the World Meteorological Organisation.
Severe weather is any dangerous meteorological phenomenon with the potential to cause damage, serious social disruption, or loss of human life. Types of severe weather phenomena vary, depending on the latitude, altitude, topography, and atmospheric conditions. High winds, hail, excessive precipitation, and wildfires are forms and effects of severe weather, as are thunderstorms, downbursts, tornadoes, waterspouts, tropical cyclones, and extratropical cyclones. Regional and seasonal severe weather phenomena include blizzards (snowstorms), ice storms, and duststorms.
A series of destructive severe thunderstorms struck southeastern Queensland, Australia, on 29 November 1992. The storms produced strong winds, flash flooding and large hailstones in the region, including the capital city of Brisbane. The storms also spawned two of the most powerful tornadoes recorded in Australia, including the only Australian tornado to be given an official 'F4' classification on the Fujita scale and the last violent tornado in Australia until 21 March 2013.
Severe Tropical Cyclone Inigo is tied with Cyclone Gwenda for being the most intense recorded cyclone in the Australian region in terms of pressure, with the possible exception of Cyclone Mahina. Inigo developed from a tropical low that crossed eastern Indonesia in late March 2003. Becoming a named tropical cyclone on 1 April, Inigo rapidly intensified as it tracked southwestward, reaching a minimum central pressure of 900 hPa on 4 April with maximum 1 minute sustained winds of 170 mph. An approaching trough weakened the cyclone and turned it to the southeast, and on 8 April, Inigo dissipated after making landfall on Western Australia, as a minimal tropical storm.
Extreme weather events in Melbourne, Australia have occurred on multiple occasions. The city has experienced a number of highly unusual weather events and extremes of weather. An increase in heat waves and record breaking temperatures in the 21st century has led to much discussion over the effects of climate change in the country.
The 1995 Mayfest storm was a damaging hailstorm that struck parts of the Dallas–Fort Worth metroplex on May 5, 1995. It was the first singular thunderstorm with a damage toll exceeding $1 billion and at the time the costliest nontornadic thunderstorm in U.S. history. Hail up to 4.5 in (11.5 cm) in diameter fell across Parker and Tarrant counties, producing hail drifts as deep as 3 ft (0.91 m) and damaging numerous buildings. The storm also struck the Fort Worth Mayfest – a local outdoor festival – pelting the roughly 10,000 people in attendance with softball-sized hail and resulting in over 60 hospitalizations. Though there were no hail-related fatalities, the combination of the slow-moving supercell that produced the hail and a larger complex of storms led to deadly flash flooding that killed 17 people in the Dallas area. Overall, 20 people were killed by the storms.
A weather warning generally refers to an alert issued by a meteorological agency to warn citizens of approaching dangerous weather. A weather watch, on the other hand, typically refers to an alert issued to indicate that conditions are favorable for the development of dangerous weather patterns, although the dangerous weather conditions themselves are not currently present.
The 2010 Victorian storms were a series of storms that passed through much of the Australian state of Victoria on 6 and 7 March 2010. One of the most severe storms passed directly over Greater Melbourne, bringing lightning, flash flooding, very large hail and strong winds to the state's capital.
The 2010 Western Australian storms were a series of storms that travelled over southwestern Western Australia on 21 and 22 March 2010. One of the more intense storm cells passed directly over the capital city of Perth between 3:30pm and 5:00pm on Monday 22 March 2010. It is the costliest natural disaster in Western Australian history, with the damage bill estimated at $1.08 billion.
The 2010 Victorian floods were a widespread series of flood events across the state of Victoria, Australia. The floods, which followed heavy rain across southeastern Australia in early September 2010, caused the inundation of about 250 homes, hundreds of evacuations and millions of dollars of damage. Weather warnings were initially issued for Victoria on Thursday 2 September and rain began to fall on the Friday, continuing through the weekend to Tuesday. Heavy rain fell in most regions of the state, particularly at higher altitudes in the state's west and northeast, flooding the upper reaches of many of Victoria's major rivers. A state of emergency was declared with State Emergency Service crews arriving from Queensland, South Australia and Tasmania. The floods proceeded an extensive drought period that had effected the entirety of Australia.
High intensity rainfall between 12–14 January 2011 caused major flooding across much of the western and central parts of the Australian state of Victoria. Several follow-up heavy rainfall events including Tropical Low Yasi caused repeated flash flooding in affected areas in early February in many of the communities affected by January's floods.
Australian east coast lows are extratropical cyclones or low-pressure systems on the coast of southeastern Australia that may be caused by both mid-latitude and tropical influences over a variety of levels in the atmosphere.
Severe Tropical Cyclone Christine was the third tropical cyclone and the second severe tropical cyclone of the 2013–14 Australian region cyclone season. It made landfall on Western Australia's Pilbara coast nearly halfway between the major towns of Karratha and Port Hedland as a category 4 cyclone on midnight of 31 December 2013.
Severe weather events or extreme weather events in Sydney, Australia, include hailstorms, thunderstorms, gale, bushfires, heatwaves, drought, and flash flooding from heavy rain. Sydney is rarely affected by cyclones, although remnants of cyclones do affect the city.
