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Vertical drafts, known as updrafts or downdrafts, are localized regions of warm or cool air that move vertically. A mass of warm air will typically be less dense than the surrounding region, and so will rise until it reaches air that is either warmer or less dense than itself. The converse will occur for a mass of cool air, and is known as ...
Squall line. A squall line, or more accurately a quasi-linear convective system (QLCS), is a line of thunderstorms, often forming along or ahead of a cold front. In the early 20th century, the term was used as a synonym for cold front (which often are accompanied by abrupt and gusty wind shifts). Linear thunderstorm structures often contain ...
Organized thunderstorms and thunderstorm clusters/lines can have longer life cycles as they form in environments of sufficient moisture, significant vertical wind shear (normally greater than 25 knots (13 m/s) in the lowest 6 kilometres (3.7 mi) of the troposphere) [5]), which aids the development of stronger updrafts as well as various forms ...
Cumulonimbus (from Latin cumulus 'swell' and nimbus 'cloud') is a dense, towering, vertical cloud, [1] typically forming from water vapor condensing in the lower troposphere that builds upward carried by powerful buoyant air currents. Above the lower portions of the cumulonimbus the water vapor becomes ice crystals, such as snow and graupel ...
The rear flank downdraft (RFD) is a region of dry air wrapping around the back of a mesocyclone in a supercell thunderstorm. [1] These areas of descending air are thought to be essential in the production of many supercellular tornadoes. Large hail within the rear flank downdraft often shows up brightly as a hook on weather radar images ...
A multicellular thunderstorm cluster is a thunderstorm that is composed of multiple convective cells, each being at a different stage in the life cycle of a thunderstorm. It appears as several anvils clustered together. A cell is an updraft/downdraft couplet. These different cells will dissipate as new cells form and continue the life of the ...
For tornadoes to form, we need thunderstorms, which have very strong updrafts and downdrafts, said Bill Gallus, a professor in the department of Geological and atmospheric sciences at Iowa State ...
Squall. A squall is a sudden, sharp increase in wind speed lasting minutes, as opposed to a wind gust, which lasts for only seconds. [1] They are usually associated with active weather, such as rain showers, thunderstorms, or heavy snow. [2] Squalls refer to the increase of the sustained winds over that time interval, as there may be higher ...