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.
An anticyclone is a weather phenomenon defined as a large-scale circulation of winds around a central region of high atmospheric pressure,clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere as viewed from above. Effects of surface-based anticyclones include clearing skies as well as cooler,drier air. Fog can also form overnight within a region of higher pressure.
In meteorology,precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle,rain,sleet,snow,ice pellets,graupel and hail. Precipitation occurs when a portion of the atmosphere becomes saturated with water vapor,so that the water condenses and "precipitates" or falls. Thus,fog and mist are not precipitation but colloids,because the water vapor does not condense sufficiently to precipitate. Two processes,possibly acting together,can lead to air becoming saturated:cooling the air or adding water vapor to the air. Precipitation forms as smaller droplets coalesce via collision with other rain drops or ice crystals within a cloud. Short,intense periods of rain in scattered locations are called showers.
The Carl-Gustaf Rossby Research Medal is the highest award for atmospheric science of the American Meteorological Society. It is presented to individual scientists,who receive a medal. Named in honor of meteorology and oceanography pioneer Carl-Gustaf Rossby,who was also its second (1953) recipient.
In meteorology,a low-pressure area,low areaor low is a region where the atmospheric pressure is lower than that of surrounding locations. Low-pressure areas are commonly associated with inclement weather,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 forces. Low-pressure systems form under areas of wind divergence that occur in the upper levels of the atmosphere (aloft). The formation process of a low-pressure area is known as cyclogenesis. In meteorology,atmospheric divergence aloft occurs in two kinds of places:
A pressure system is a peak or lull in the sea level pressure distribution. The surface pressure at sea level varies minimally,with the lowest value measured 87 kilopascals (26 inHg) and the highest recorded 108.57 kilopascals (32.06 inHg). High- and low-pressure systems evolve due to interactions of temperature differentials in the atmosphere,temperature differences between the atmosphere and water within oceans and lakes,the influence of upper-level disturbances,as well as the amount of solar heating or radiationized cooling an area receives. Pressure systems cause weather to be experienced locally. Low-pressure systems are associated with clouds and precipitation that minimize temperature changes throughout the day,whereas high-pressure systems normally associate with dry weather and mostly clear skies with larger diurnal temperature changes due to greater radiation at night and greater sunshine during the day. Pressure systems are analyzed by those in the field of meteorology within surface weather maps.
This is a list of meteorology topics. The terms relate to meteorology,the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting.
A rainband is a cloud and precipitation structure associated with an area of rainfall which is significantly elongated. Rainbands can be stratiform or convective,and are generated by differences in temperature. When noted on weather radar imagery,this precipitation elongation is referred to as banded structure. Rainbands within tropical cyclones are curved in orientation. Rainbands of tropical cyclones contain showers and thunderstorms that,together with the eyewall and the eye,constitute a hurricane or tropical storm. The extent of rainbands around a tropical cyclone can help determine the cyclone's intensity.
A mesoscale convective system (MCS) is a complex of thunderstorms that becomes organized on a scale larger than the individual thunderstorms but smaller than extratropical cyclones,and normally persists for several hours or more. A mesoscale convective system's overall cloud and precipitation pattern may be round or linear in shape,and include weather systems such as tropical cyclones,squall lines,lake-effect snow events,polar lows,and mesoscale convective complexes (MCCs),and generally forms near weather fronts. The type that forms during the warm season over land has been noted across North and South America,Europe,and Asia,with a maximum in activity noted during the late afternoon and evening hours.
The rear-inflow jet is a component of bow echoes in a mesoscale convective system that aids in creating a stronger cold pool and downdraft. The jet forms as a response to a convective circulation having upshear tilt and horizontal pressure gradients. The cold pool that comes from the outflow of a storm forms an area of high pressure at the surface. In response to the surface high and warmer temperatures aloft due to convection,a mid-level mesolow forms behind the leading edge of the storm.
In meteorology,the different types of precipitation often include the character,formation,or phase of the precipitation which is falling to ground level. There are three distinct ways that precipitation can occur. Convective precipitation is generally more intense,and of shorter duration,than stratiform precipitation. Orographic precipitation occurs when moist air is forced upwards over rising terrain and condenses on the slope,such as a mountain.
An air-mass thunderstorm,also called an "ordinary","single cell","isolated" or "garden variety" thunderstorm,is a thunderstorm that is generally weak and usually not severe. These storms form in environments where at least some amount of Convective Available Potential Energy (CAPE) is present,but with very low levels of wind shear and helicity. The lifting source,which is a crucial factor in thunderstorm development,is usually the result of uneven heating of the surface,though they can be induced by weather fronts and other low-level boundaries associated with wind convergence. The energy needed for these storms to form comes in the form of insolation,or solar radiation. Air-mass thunderstorms do not move quickly,last no longer than an hour,and have the threats of lightning,as well as showery light,moderate,or heavy rainfall. Heavy rainfall can interfere with microwave transmissions within the atmosphere.
Howard Bruce Bluestein is a research meteorologist known for his mesoscale meteorology,severe weather,and radar research. He is a major participant in the VORTEX projects. A native of the Boston area,Dr. Bluestein received his Ph.D. in 1976 from MIT. He has been a professor of meteorology at the University of Oklahoma (OU) since 1976.
The following is a glossary of tornado terms. It includes scientific as well as selected informal terminology.
The Jule G. Charney Award is the American Meteorological Society's award granted to "individuals in recognition of highly significant research or development achievement in the atmospheric or hydrologic sciences". The prize was originally known as the Second Half Century Award,and first awarded to mark to fiftieth anniversary of the society.
Bhupendra Nath Goswami is an Indian meteorologist,climatologist,a former director of the Indian Institute of Tropical Meteorology (IITM). and a Pisharoty Chair Professor at the Indian Institute of Science Education and Research. He is known for his researches on the Indian monsoon dynamics and is an elected fellow of all the three major Indian science academies viz. Indian National Science Academy,Indian Academy of Sciences,and the National Academy of Sciences,India as well as The World Academy of Sciences. The Council of Scientific and Industrial Research,the apex agency of the Government of India for scientific research,awarded him the Shanti Swarup Bhatnagar Prize for Science and Technology,one of the highest Indian science awards for his contributions to Earth,Atmosphere,Ocean and Planetary Sciences in 1995.
Peter John Webster is a meteorologist and climate dynamicist relating to the dynamics of large-scale coupled ocean-atmosphere systems of the tropics,notably the Asian monsoon. Webster holds degrees in applied physics,mathematics and meteorology. Webster studies the basic dynamics of the coupled ocean-atmosphere system in the tropics and has applied this basic knowledge to developing warning systems for extreme weather events in Asia. He has served on a number of prestigious national and international committees including the World Climate Research Program's Joint Scientific Committee (1983-1987),chaired the international Tropical Ocean Global Atmospheric (TOGA) organizing committee (1988–94) and was co-organizer of the multinational TOGA Couple Ocean-Atmosphere (1993). He is Emeritus Professor in Earth and Atmospheric Sciences at Georgia Institute of Technology and co-founder and Chief Scientist of Climate Forecast Applications Network LLC,a weather and climate services company.
Susan Claire van den Heever is a South African atmospheric scientist who is a professor at Colorado State University. Her research considers cloud physics and mesoscale modelling. She is a fellow of the American Meteorological Society and an editor of the Journal of the Atmospheric Sciences.
Boualem Khouider is an Algerian-Canadian applied mathematician,climate scientist,academic,and author. He is a professor,and former Chair of Mathematics and Statistics at the University of Victoria.
Krzysztof Edward Haman is a Polish atmospheric physicist,professor at the University of Warsaw,and member of the Polish Academy of Sciences.
