Hail is a form of solid precipitation. It is distinct from ice pellets, though the two are often confused. It consists of balls or irregular lumps of ice, each of which is called a hailstone. Ice pellets generally fall in cold weather, while hail growth is greatly inhibited during cold surface temperatures.
Cumulonimbus is a dense, towering vertical cloud, forming from water vapor carried by powerful upward air currents. If observed during a storm, these clouds may be referred to as thunderheads. Cumulonimbus can form alone, in clusters, or along cold front squall lines. These clouds are capable of producing lightning and other dangerous severe weather, such as tornadoes and hailstones. Cumulonimbus progress from overdeveloped cumulus congestus clouds and may further develop as part of a supercell. Cumulonimbus is abbreviated Cb.
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.
The United Kingdom straddles the higher mid-latitudes between 49° and 61°N on the western seaboard of Europe. Since the UK is always in or close to the path of the polar front jet stream, frequent changes in pressure and unsettled weather are typical. Many types of weather can be experienced in a single day. In general the climate of the UK is cool and often cloudy and rainy. High temperatures are infrequent.
A storm is any disturbed state of an environment or in an astronomical body's atmosphere especially affecting its surface, and strongly implying severe weather. It may be marked by significant disruptions to normal conditions such as strong wind, tornadoes, hail, thunder and lightning, heavy precipitation, heavy freezing rain, strong winds, or wind transporting some substance through the atmosphere as in a dust storm, blizzard, sandstorm, etc.
A supercell is a thunderstorm characterized by the presence of a mesocyclone: a deep, persistently rotating updraft. For this reason, 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.
Severe storms in Australia refers to the storms, including cyclones, which have caused severe damage in Australia.
A cumulonimbus incus also known as an anvil cloud is a cumulonimbus cloud which has reached the level of stratospheric stability and has formed the characteristic flat, anvil-top shape. It signifies the thunderstorm in its mature stage, succeeding the cumulonimbus calvus stage. Cumulonimbus incus is a sub-form of Cumulonimbus capillatus.
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. Extreme weather phenomena which cause extreme heat, cold, wetness or drought often will bring severe weather events. One of the principle effects of anthropogenic climate change is changes in severe and extreme weather patterns.
Atmospheric convection is the result of a parcel-environment instability, or temperature difference layer in the atmosphere. Different lapse rates within dry and moist air masses lead to instability. Mixing of air during the day which expands the height of the planetary boundary layer leads to increased winds, cumulus cloud development, and decreased surface dew points. Moist convection leads to thunderstorm development, which is often responsible for severe weather throughout the world. Special threats from thunderstorms include hail, downbursts, and tornadoes.
The British Isles are an archipelago off the northwest coast of Europe, consisting of the islands of Great Britain and Ireland along with smaller surrounding ones. Its position allows dry continental air from Eurasia to meet wetter air from the Atlantic Ocean, which causes the weather to be highly variable, often changing many times during the day. It is defined as a temperate oceanic climate, or Cfb on the Köppen climate classification system. It is significantly warmer than other regions on the same latitude, previously thought to be due to the warmth provided by the Gulf Stream; however, this has been disproven, and most of the mild temperatures have been linked to the Rocky Mountains and the heat storing capabilities of the North Atlantic Ocean. Temperatures do not often switch between great extremes, with warm summers and mild winters.
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 Spanish Plume is a weather pattern in which a plume of warm air moves from the Iberian plateau or the Sahara to northwest Europe giving rise to thunderstorms. This meteorological pattern can lead to extreme high temperatures and intense rainfall during the summer months, with potential for flash flooding, damaging hail, and tornado formation. Some of these intense thunderstorms are formed from thermal lows, are also known as heat lows. Thermal lows can be semipermanent features around some parts of Europe, particularly in the summer season. These thermal lows can be developed or created around Spain, Portugal, France etc., during the summer season because of the intense heat. Thermal low pressure can be located around the world, particularly in the summer or in tropical regions.
Hailstorm Alley is a colloquial term referring to an area of south and central Alberta, Canada where hail storms are frequently produced. These storms frequently produce hail that is damaging to property. This area stretches from High River in southern Alberta, northward through Calgary, through Red Deer to Lacombe and then westward to Rocky Mountain House. It is known to be one of the worst areas in the world for damaging hail produced by thunderstorms. These are regarded as loose boundaries. While this area is common for damaging hailstorms, the reality is damaging hailstorms occur over much of central and southern Alberta every summer. The City of Calgary is regarded as the hailstorm capital of Canada.
The 1808 United Kingdom heat wave was a period of exceptionally high temperatures during July 1808. In the Central England Temperature series, dating back to 1659, at the time it was the 2nd hottest July on record, the hottest since 1783. The month included some of the highest temperatures ever recorded in the UK.
Severe storm events in Sydney, New South Wales, Australia are not uncommon and include hailstorms, wind storms, and flash flooding from rain caused by East coast lows, black nor'easters and/or tropical cyclone remnants. East coast lows are low pressure depressions or extratropical cyclones that can bring significant damage by heavy rain, cyclonic winds and huge swells. Sydney is rarely affected by cyclones, although remnants of cyclones do affect the city.
A long-lived, destructive tornado outbreak sequence caused widespread damage and numerous casualties across the United States during mid- to late-May and early June. Over the course of 19 days, 198 tornadoes touched down across 25 states from California to Connecticut. There were 66 significant (F2+) tornadoes during the event, including 15 F3 tornadoes and four F4 tornadoes. In addition to the tornadoes, storms across the region produced destructive straight-line winds, large hail, heavy rainfall that led to flash flooding, and frequent lightning. Overall, the outbreak sequence caused three fatalities, 168 injuries, and caused $36.275 million in damage. There were additional casualties that occurred as a result of non-tornadic weather events as well.
