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Stationary Front
A stationary front (or quasi-stationary front) is a weather front or transition zone between two air masses when each air mass is advancing into the other at speeds less than 5 knots (about 6 miles per hour or about 9 kilometers per hour) at the ground surface. These fronts are typically depicted on weather maps as a solid line with alternating blue spikes (pointing toward the warmer air) and red domes (facing the colder air). Development A stationary front may form when a cold or warm front slows down or grows over time from underlying surface temperature differences, like a coastal front. Winds on the cold air and warm air sides often flow nearly parallel to the stationary front, often in opposite directions along either side of the stationary front. A stationary front usually remains in the same area for hours to days and may undulate as atmospheric waves move eastward along the front. Stationary fronts may change into a cold or warm front, and may form one or more extratro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stationary Front Symbol
Stationary may refer to: * "Stationary", a song from ''Copacetic'' (Knuckle Puck album) * a common misspelling of "stationery", meaning office supplies * stationary process In mathematics and statistics, a stationary process (also called a strict/strictly stationary process or strong/strongly stationary process) is a stochastic process whose statistical properties, such as mean and variance, do not change over time. M ..., in mathematics and statistics, a process whose probability distribution does not change over time. See also * * {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2020-03-14 Surface Weather Map NOAA
The symbol , known in Unicode as hyphen-minus, is the form of hyphen most commonly used in digital documents. On most keyboards, it is the only character that resembles a minus sign or a dash, so it is also used for these. The name ''hyphen-minus'' derives from the original ASCII standard, where it was called ''hyphen (minus)''. The character is referred to as a ''hyphen'', a ''minus sign'', or a ''dash'' according to the context where it is being used. Description In early typewriters and character encodings, a single key/code was almost always used for hyphen, minus, various dashes, and strikethrough, since they all have a similar appearance. The current Unicode Standard specifies distinct characters for several different dashes, an unambiguous minus sign (sometimes called the ''Unicode minus'') at code point U+2212, an unambiguous hyphen (sometimes called the ''Unicode hyphen'') at U+2010, the hyphen-minus at U+002D and a variety of other hyphen symbols for various uses. Wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weather Front
A weather front is a boundary separating air masses for which several characteristics differ, such as air density, wind, temperature, and humidity. Disturbed and unstable weather due to these differences often arises along the boundary. For instance, cold fronts can bring bands of thunderstorms and cumulonimbus precipitation or be preceded by squall lines, while warm fronts are usually preceded by stratiform precipitation and fog. In summer, subtler humidity gradients known as dry lines can trigger severe weather. Some fronts produce no precipitation and little cloudiness, although there is invariably a wind shift. Cold fronts generally move from west to east, whereas warm fronts move poleward, although any direction is possible. Occluded fronts are a hybrid merge of the two, and stationary fronts are stalled in their motion. Cold fronts and cold occlusions move faster than warm fronts and warm occlusions because the dense air behind them can lift as well as push the warme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Air Mass
In meteorology, an air mass is a volume of air defined by its temperature and humidity. Air masses cover many hundreds or thousands of square miles, and adapt to the characteristics of the surface below them. They are classified according to latitude and their continental or maritime source regions. Colder air masses are termed polar or arctic, while warmer air masses are deemed tropical. Continental and superior air masses are dry, while maritime and monsoon air masses are moist. Weather fronts separate air masses with different density (temperature or moisture) characteristics. Once an air mass moves away from its source region, underlying vegetation and body of water, water bodies can quickly modify its character. Classification schemes tackle an air mass's characteristics, as well as modification. Classification and notation The Tor Bergeron, Bergeron classification is the most widely accepted form of air mass classification, though others have produced more refined versi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold Front
A cold front is the leading edge of a cooler mass of air at ground level that replaces a warmer mass of air and lies within a pronounced surface Trough (meteorology), trough of Low-pressure area, low pressure. It often forms behind an extratropical cyclone (to the west in the Northern Hemisphere, to the east in the Southern Hemisphere, Southern), at the leading edge of its cold air Advection#Meteorology, advection pattern—known as the cyclone's dry "conveyor belt" flow. Temperature differences across the boundary can exceed from one side to the other. When enough moisture is present, rain can occur along the boundary. If there is significant Convective instability, instability along the boundary, a Squall line, narrow line of thunderstorms can form along the frontal zone. If instability is weak, a broad shield of rain can move in behind the Weather front, front, and evaporative cooling of the rain can increase the temperature difference across the front. Cold fronts are stronger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Warm Front
Warm, WARM, or Warmth may refer to: * A somewhat high temperature; heat * Kindness Music Albums * ''Warm'' (Herb Alpert album), 1969 * ''Warm'' (Jeff Tweedy album), 2018 * ''Warm'' (Johnny Mathis album), 1958, and the title song * ''Warm'' (The Lettermen album), 1967, and the title song * ''Warmer'' (Jeff Tweedy album), 2019 * ''Warmer'' (Randy VanWarmer album), 1979 Songs * "Warm", by Ariana Grande from '' Eternal Sunshine Deluxe: Brighter Days Ahead'', 2025 * "Warm", by Charli XCX featuring Haim from '' Charli'', 2019 * "Warm", by Majid Jordan from '' Majid Jordan'', 2016 * "Warm", by Swans from '' The Great Annihilator'', 1995 * "Warmer", by Bea Miller from '' Chapter Two: Red'' and ''Aurora'', 2017 * "Warmth", by Bastille from Wild World, 2016 * "Warmth", by C418 from '' Minecraft - Volume Beta'', 2013 * "Warmth", by Janet Jackson from '' Damita Jo'', 2004 Other uses * ''Warm.'', taxonomic author abbreviation of Eugenius Warming (1841–1924), Danish botanist * WARM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Wave
An atmospheric wave is a periodic disturbance in the fields of atmospheric variables (like surface pressure or geopotential height, temperature, or wind velocity) which may either propagate ('' traveling wave'') or be stationary (''standing wave''). Atmospheric waves range in spatial and temporal scale from large-scale planetary waves (Rossby waves) to minute sound waves. Atmospheric waves with periods which are harmonics of 1 solar day (e.g. 24 hours, 12 hours, 8 hours... etc.) are known as atmospheric tides. Causes and effects The mechanism for the forcing of the wave, for example, the generation of the initial or prolonged disturbance in the atmospheric variables, can vary. Generally, waves are either excited by heating or dynamic effects, for example the obstruction of the flow by mountain ranges like the Rocky Mountains in the U.S. or the Alps in Europe. Heating effects can be small-scale (like the generation of gravity waves by convection) or large-scale (the formatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ageostrophy
Ageostrophy (or ageostrophic flow) is the difference between the ''actual'' wind or current and the geostrophic wind or geostrophic current. Since geostrophy is an exact balance between the Coriolis force and the pressure gradient force, ageostrophic flow reflects an imbalance, and thus is often implicated in disturbances, vertical motions (important for weather), and rapid changes with time. Ageostrophic flow reflects the existence of all the other terms in the momentum equation neglected in that idealization, including friction and material acceleration Dv/Dt, which includes the centrifugal force in curved flow. See also * geostrophic *geostrophic wind In atmospheric science, geostrophic flow () is the theoretical wind that would result from an exact balance between the Coriolis force and the pressure gradient force. This condition is called '' geostrophic equilibrium'' or ''geostrophic balanc ... References External linksMeteo 422 – Lecture 17 – The Omega Equation Al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frontogenesis
Frontogenesis is a meteorological process of tightening of horizontal temperature gradients to produce fronts. In the end, two types of fronts form: cold fronts and warm fronts. A cold front is a narrow line where temperature decreases rapidly. A warm front is a narrow line of warmer temperatures and essentially where much of the precipitation occurs. Frontogenesis occurs as a result of a developing baroclinic wave. According to Hoskins & Bretherton (1972, p. 11), there are eight mechanisms that influence temperature gradients: horizontal deformation, horizontal shearing, vertical deformation, differential vertical motion, latent heat release, surface friction, turbulence and mixing, and radiation. Semigeostrophic frontogenesis theory focuses on the role of horizontal deformation and shear. Kinematics Horizontal deformation in mid-latitude cyclones concentrates temperature gradients—cold air from the poles and warm air from the equator. Horizontal shear has two effects o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloud
In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, frozen crystals, or other particles, suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may compose the droplets and crystals. On Earth, clouds are formed as a result of saturation of the air when it is cooled to its dew point, or when it gains sufficient moisture (usually in the form of water vapor) from an adjacent source to raise the dew point to the ambient temperature. Clouds are seen in the Earth's homosphere, which includes the troposphere, stratosphere, and mesosphere. Nephology is the science of clouds, which is undertaken in the cloud physics branch of meteorology. The World Meteorological Organization uses two methods of naming clouds in their respective layers of the homosphere, Latin and common name. Genus types in the troposphere, the atmospheric layer closest to Earth's surface, have Latin names because of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Precipitation (meteorology)
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, rain and snow mixed ("sleet" in Commonwealth usage), snow, ice pellets, graupel and hail. Precipitation occurs when a portion of the atmosphere becomes saturated with water vapor (reaching 100% relative humidity), so that the water condenses and "precipitates" or falls. Thus, fog and mist are not precipitation; their water vapor does not condense sufficiently to precipitate, so fog and mist do not fall. (Such a non-precipitating combination is a colloid.) Two processes, possibly acting together, can lead to air becoming saturated with water vapor: 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 shower (p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Storm Train
In meteorology, training denotes repeated areas of rain, typically associated with thunderstorms, that move over the same region in a relatively short period. Training thunderstorms are capable of producing excessive rainfall totals, often causing flash flooding. The name ''training'' is derived from how a train and its cars travel along a track (moving along a single path), without the track moving. Formation Showers and thunderstorms along thunderstorm trains usually develop in one area of stationary instability, and are advanced along a single path by prevailing winds. Additional showers and storms can also develop when the gust front from a storm collides with warmer air outside of the storm. The exact process repeats in the new storms until overall conditions in the surrounding atmosphere become too stable to support thunderstorm activity. Showers and storms can also develop along stationary fronts, and winds move them down the front. The showers that often accompan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
