Troughs upper level lows
When the height contours bend strongly to the south, (as in the diagram below), it is called a TROUGH. Strong troughs are typically preceded by stormy weather and colder air at the surface.
Trough In meteorology, an elongated area of relatively low atmospheric pressure; the opposite of a ridge.
A Tropical Upper Tropospheric Trough (TUTT) is a trough situated in upper-level (at about 200 hPa) tropics. Its formation is usually caused by the expansion of the Trough of Westeriles Wind to the tropics.
Trough
A trough of low pressure is an elongated area where atmospheric pressure is low relative to its immediate surroundings.
Trough
An elongated area of relatively low atmospheric pressure, usually not associated with a closed circulation, and thus used to distinguish from a closed low.
Trough - an elongated area of relatively low atmospheric pressure; the opposite of ridge
True North - the direction from any point on the earth's surface toward the geographic North Pole ...
Trough - An area of low pressure. Cyclonically curving winds.
TUTT - Tropical Upper Tropospheric Trough.
Upwelling - A rising-up of colder water.
TROUGH An elongated area of low atmospheric pressure that is associated with an area of minimum cyclonic circulation. The opposite of a ridge.
TROUGH: An elongated area of low pressure at the surface or aloft.
TULE FOG: Radiation fog in the Central Valley. It forms during night and morning hours in late fall and winter months following the first significant rainfall.
TROUGH: An elongated area of low pressure at the surface or aloft.
TSUNAMI: An ocean wave generated by a submarine earthquake, volcano or landslide. (Also known as a seismic sea wave, and incorrectly as a tidal wave).
Trough- an elongated relatively low pressure area between two high pressure areas.
Typhoon- a hurricane that occurs in eastern Asia.
- U - ...
Trough
(Thalwet) An elongated area of relatively low atmospheric pressure.
Turbulence
(Turbulent Flow) Random and continuously changing air motion which are superposed on the mean motion of the air.
TROUGH (TROF)- Longwave of lower heights aloft. A cold low level air mass will cause there to be troughing aloft. Rising air over a broad region such as from a mid-latitude cyclone can also create troughing.
TS, TSRA- Thunderstorm ...
Trough - An elongated area of low pressure.
Unstable Air - Air that is warmer than its surroundings and as such tends to rise, leading to the formation of clouds and possibly precipitation.
lee trough"(Same as dynamic trough.) A pressure trough formed on the lee side of a mountain range in situations where the wind is blowing with a substantial component across the mountain ridge; ...
Wave Trough The lowest point in a wave.
Wavelength The distance a wave will travel in the time required to generate one cycle. The distance between two consecutive wave peaks (or other reference points) in space.
minor trough - A pressure trough of smaller scale than a long-wave trough. It ordinarily moves rapidly and is associated with a migratory cyclonic disturbance in the lower troposphere. See short wave.
Trough: It is an extended area of relatively lower atmospheric pressure. It can be the extension of a cyclone. It is the opposite of ridge and generally is associated with severe weather, as the cyclone itself.
TROUGH: An elongated area of low atmospheric pressure.
VIRGA: Falling precipitation that evaporates before reaching the ground.
WARM FRONT: A leading boundary of a warm airmass that is often moving into an area influenced by a cooler airmass.
Trough- An elongated low-pressure system that generally stretches north and south.
Typhoon- A tropical cyclone with winds of 74 miles per hour or greater that occurs west of the International Date Line.
Trough: on a weather chart, a narrow, elongated area of relatively low pressure.Turbulence: irregular motion of the atmosphere, as indicated by gusts and lulls in the wind.
U
Unstable air: see absolutely unstable air.
Trough
An elongated area of low pressure, often associated with a wind shift and showery weather.
Trowal ...
Trough
An elongated low-pressure system that enhances showers into longer spells of rain or snow.
Tsunami ...
Trough - It's an elongated area of low pressure.
Tsunami - A Japanese term for an unusually large ocean wave caused by undersea earthquake, landslide, or volcanic eruption.
TROUGH - An elongated region of low air pressure in the atmosphere but not circular in nature. Sometimes may be called an AXIS TROUGH if it is extending from a cyclonic low pressure region. Also called a WAVE.
A trough in the prevailing westerly flow aloft which is characterized by large length and (usually) long duration. Generally, there are no more than about five longwave troughs around the Southern Hemisphere at any given time.
A trough in the prevailing westerly flow aloft which is characterized by large length and (usually) long duration.
Loop Prominence System
(abbrev. LPS) In solar-terrestrial terms, a system of loop prominences associated with major flares.
Trowal - Trough of Warm Air Aloft. An occluded front where cold air is on both sides and the warm air has been completely lifted.
Polar front - divies air polar air masses from tropical air masses.
EQUATORIAL TROUGH
The quasi-continuous area of low pressure between the subtropical high pressure areas in both the Northern and Southern Hemisphere.
Related terms: Intertropical Convergence Zone (ITCZ) and doldrums ...
LONG WAVE TROUGH A wave in the prevailing westerly flow aloft which is characterized by a large length and amplitude. A long wave moves slowly and is persistent. Its position and intensity govern weather patterns over a period of days or weeks.
Equatorial trough
The zone of relatively low pressure, which lies between the subtropical anticyclones of the two hemispheres.
Equilibrium level ...
PRE-FRONTAL TROUGH An elongated area of relatively low pressure preceding a cold front that is usually associated with a shift in wind direction. Related term: trough ...
Positive-tilt Trough - An upper level system which is tilted to the east with increasing latitude (i.e., from southwest to northeast).
Tropical Wave: A trough or cyclonic curvature maximum in the trade-wind easterlies. The wave may reach maximum amplitude in the lower middle troposphere.
Opposite of a trough.River flood warningIssued when main stem rivers are expected to reach a level above flood stage.Roll cloudA relatively rare, low-level horizontal, tube-shaped accessory cloud completely detached from the cumulonimbus base.
Although, strictly speaking, all lows are closed, this term distinguishes a low from a trough on a surface chart, and on upper level charts, it accentuates that the circulation is "closed." A form of cut-off low.
shortwave troughA relatively small-scale trough that is superimposed on and propagates through the longer wavelength Rossby waves.single-column modeling (SCM)An approach to the development and testing of cloud formation and parameterizations.
a watershed to react to a given rainfall eventRetrogression(or Retrograde Motion) - Movement of a weather system in a direction opposite to that of the basic flow in which it is embedded, usually referring to a closed low or a longwave trough ...
Depression In meteorology, an area of low pressure; a low or trough.
What is a trough?
A. A trough on a mean sea level pressure chart, (or an upper air contour chart) can be picked out by an arrangement of isobars (contours) which are concave towards an area of low pressure (low contour height) along a particular ...
Wavelenght: Is measured from "Crest to Crest" or "Trough to Trough".
Weather:The state of the atmosphere at a given location at a given time.
Weather Acronyms: ...
The term usually is used to distinguish a low pressure area aloft from a low-pressure trough. Closed lows aloft typically are partially or completely detached from the main westerly current, and thus move relatively slowly (see Cutoff Low).
These boundaries are often associated with a strong, migratory surface low pressure system and strong short wave trough at 500 mb (strong dynamic forcing).
The distance between successive maxima (crests) or minima (troughs) of a wave train, measured along the direction of wave propagation. The wavelength is one of the ways used to identify wave phenomena.
These are rebel clouds which are left behind when a large cloud mass, usually associated with a surface low or upper air trough, exits the state.
DEPRESSION In meteorology, it is another name for an area of low pressure, a low, or trough. It also applies to a stage of tropical cyclone development and is known as a tropical depression to distinguish it from other synoptic features.
Short waves Relatively small short-wavelength ripples (troughs and ridges) superimposed on long waves in the planetary-scale westerlies; they propagate with the air flow through long waves in the middle and upper troposphere.
Wavelength The distance between successive crests, troughs, or identical parts of a wave.
Weather The condition of the atmosphere at any particular time and place.
Tropical wave: A kink or bend in the normally straight flow of surface air in the tropics which forms a low pressure trough, or pressure boundary, and showers and thunderstorms. Can develop into a tropical cyclone. ...
Amplitude: Half the height from the crest to the trough of the wave.
NOAA National Weather Service - Cite This Source - This Definition
Browse Related Terms: backing, BCKG, Plume Impingement, Pre-Frontal Trough, SHFT, SWLY, Veering, Veering Winds, VR, Wind Shift, Wind Shift Line, WSHFT
All > Science > Weather ...
When meterologists say that a pattern will retrograde, they mean that the troughs and ridges will end up further west than they were previously.
Low - a low pressure area with a distinct center of cyclonic circulation which can be completely encircled by one or more isobars or height contour lines. The term usually is used to distinguish a low pressure area aloft from a low-pressure trough.
 See also: Air, Pressure, Surface, Weather, Temperature
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