A well‐developed line of cumulonimbus clouds

Abstract Clouds within the inner regions of tropical cyclones are unlike those anywhere else in the atmosphere. Convective clouds contributing to cyclogenesis have rotational and deep intense updrafts but tend to have relatively weak downdrafts. Within the eyes of mature tropical cyclones, stratus clouds top a boundary layer capped by subsidence. An outward-sloping eyewall cloud is controlled by adjustment of the vortex toward gradient-wind balance, which is maintained by a slantwise current transporting boundary layer air upward in a nearly conditionally symmetric neutral state. This balance is intermittently upset by buoyancy arising from high-moist-static-energy air entering the base of the eyewall because of the radial influx of low-level air from the far environment, supergradient wind in the eyewall zone, and/or small-scale intense subvortices. The latter contain strong, erect updrafts. Graupel particles and large raindrops produced in the eyewall fall out relatively quickly while ice splinters left aloft surround the eyewall, and aggregates are advected radially outward and azimuthally up to 1.5 times around the cyclone before melting and falling as stratiform precipitation. Electrification of the eyewall cloud is controlled by its outward-sloping circulation. Outside the eyewall, a quasi-stationary principal rainband contains convective cells with overturning updrafts and two types of downdrafts, including a deep downdraft on the band’s inner edge. Transient secondary rainbands exhibit propagation characteristics of vortex Rossby waves. Rainbands can coalesce into a secondary eyewall separated from the primary eyewall by a moat that takes on the structure of an eye. Distant rainbands, outside the region dominated by vortex dynamics, consist of cumulonimbus clouds similar to non–tropical storm convection.

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Cumulonimbus clouds

Weather ◽

10.1002/wea.3689 ◽

2020 ◽

Vol 75 (3) ◽

pp. 87-87

Keyword(s):

Cumulonimbus Clouds

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Weather information provided to pilots: Thunderstorms in the terminal area

MAD - Magazine of Aviation Development ◽

10.14311/mad.2019.01.02 ◽

2019 ◽

Vol 7 (1) ◽

pp. 12-16

Author(s):

Martin Málek ◽

Jakub Hospodka

Keyword(s):

Current System ◽

Information Provision ◽

Weather Data ◽

Commercial Aircraft ◽

Additional Information ◽

Weather Information ◽

Effective Decision ◽

Effective Decision Making ◽

Cumulonimbus Clouds ◽

Terminal Area

<p>The article evaluates current system of weather information provision to pilots of commercial aircraft in flight. Specifically it focuses on what is provided in case of thunderstorms present in the terminal area opposed to what is needed from pilot’s perspective for effective decision making. Contents and availability of aviation weather messages are considered and suggestions for optimization of information sources are made. Benefits of the provision of additional information containing the position of cumulonimbus clouds are explained on the examples of operational scenarios. The scenarios are based on historical weather data, however solutions and decisions are fictional. Explanation of different scenario solutions based on information available in the cockpit is provided and the consequences evaluated.</p>

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