Weather — page 22 of 38

3,760 terms including subtopics (3,094 terms filed directly here)

Subtopics

Weather terms

  1. Misoscale The scale of meteorological phenomena that ranges in size from 40 meters to about 4 kilometers. It includes rotation within a thunderstorm.
  2. MIST A visible aggregate of minute water particles suspended in the atmosphere that reduces visibility to less than 7 statute miles, but greater than or equal…
  3. Mixed Layer An atmospheric layer, usually the layer immediately above the ground, in which pollutants are well mixed by convective or shear-produced turbulence.
  4. Mixed Precipitation Any of the following combinations of freezing and frozen precipitation: snow and sleet, snow and freezing rain, or sleet alone. Rain may also be present.
  5. Mixing Depth Vertical distance between the ground and the altitude to which pollutants are mixed by turbulence caused by convective currents or vertical shear in the…
  6. Mixing Heights The height to which a parcel of air, or a column of smoke, will rise, mix or disperse. A column of smoke will remain trapped below this height.
  7. Mixing Ratio The ratio of the weight of water vapor in a specified volume (such as an air parcel) to the weight of dry air in that same volume.
  8. MJO Madden-Julian Oscillation- Tropical rainfall exhibits strong variability on time scales shorter than the seasonal El Niño-Southern Oscillation (ENSO).
  9. MLCAPE Mean Layer CAPE - CAPE calculated using a parcel consisting of Mean Layer values of temperature and moisture from the lowest 100 mb above ground level.
  10. MLLI Mean Layer Lifted Index - Lifted Index (LI) calculated using a parcel consisting of Mean Layer values of temperature and moisture from the lowest 100 mb…
  11. MLLW (Mean Lower Low Water) - A tidal datum. The average of the lower low water height of each tidal day observed over the National Tidal Datum Epoch.
  12. MLW (Mean Low Water) - A tidal datum. The average of all the low water heights observed over the National Tidal Datum Epoch.
  13. MNLY Mainly
  14. Mobile Facility The ARM Mobile Facility (AMF) was first deployed in 2005; it consists of large shipping containers converted into laboratories.
  15. MOBY Marine Optical Buoy. It measures solar radiation to calibrate satellite ocean color instruments.
  16. model See Exhibit.
  17. Model Output Statistics (abbrev. MOS) - the Hydrometeorological Center (HPC) produces a short range (6 to 60 hours) MOS (Model Output Statistics) guidance package generated from…
  18. Model year Refers to the "sales" model year; for example, vehicles sold during the period from October 1 to the next September 31 is considered one model year.
  19. Moderate Flooding The inundation of secondary roads; transfer to higher elevation necessary to save property -- some evacuation may be required.
  20. Moderate Risk (of severe thunderstorms) Severe thunderstorms are expected to affect between 5 and 10 percent of the area.
  21. Moist Adiabat The line on a Skew T-Log P chart that depicts the change in temperature of saturated air as it rises and undergoes cooling due to adiabatic expansion.
  22. Moist Adiabatic Lapse Rate (abbrev. MALR)- The rate at which the temperature of a parcel of saturated air decreases as the parcel is lifted in the atmosphere.
  23. moist adiabatic lapse rate (MALR) (MALR) The rate at which the temperature of a parcel of saturated air decreases as the parcel is lifted in the atmosphere.
  24. Moist-adiabatic (Also known as saturation-adiabatic process.) An adiabatic process for which the air is saturated and may contain liquid water.
  25. Moisture The amount of water and other components present in the biomass sample that are volatilized at 105°C. (Source: Ehrman, T.
  26. Moisture Advection Transport of moisture by horizontal winds.
  27. Moisture Convergence A measure of the degree to which moist air is converging into a given area, taking into account the effect of converging winds and moisture advection.
  28. Moisture Equivalent The ratio of (1) the weight of water which the soil, after saturation, will retain against a centrifugal force 1,000 times the force of gravity, to (2)…
  29. Moisture Ridge An axis of relatively high dew point values. This axis is sometimes referred to as a 'moist tongue'.
  30. Molecule The smallest particle of a substance that has all of the physical and chemical properties of that substance. Molecules are made up of one or more atoms.
  31. Monitor Stage The stage which, when reached by a rising stream, represents the level where appropriate officials (e.g.
  32. Monostatic Radar A radar that uses a common antenna for both transmitting and receiving.
  33. Monsoon A thermally driven wind arising from differential heating between a land mass and the adjacent ocean that reverses its direction seasonally.
  34. Monthly Climatological Report This climatological product is issued once a month by each National Weather Service office. It is a mix of tabular and narrative information.
  35. Montreal Protocol on Substances that Deplete the Ozone Layer The Montreal Protocol and its amendments control the phaseout of ozone depleting substances production and use.
  36. Morning Glory An elongated cloud band, visually similar to a roll cloud, usually appearing in the morning hours, when the atmosphere is relatively stable.
  37. MOS Model Output Statistics - the Hydrometeorological Center (HPC) produces a short range (6 to 60 hours) MOS guidance package generated from the NGM, GFS…
  38. Mostly Clear When the 1/8th to 2/8ths of the sky is covered by with opaque (not transparent) clouds.
  39. Mostly Cloudy When the 6/8th to 7/8ths of the sky is covered by with opaque (not transparent) clouds. Same as Considerable Cloudiness .
  40. Mostly Sunny When the 1/8th to 2/8ths of the sky is covered by with opaque (not transparent) clouds Same as Mostly Clear, except only applicable during daylight hours.
  41. Motor gasoline A complex mixture of relatively volatile hydrocarbons, with or without small quantities of additives, obtained by blending appropriate refinery streams to…
  42. Mount Pinatubo A volcano in the Philippine Islands that erupted in 1991. The eruption of Mount Pinatubo ejected enough particulate and sulfate aerosol matter into the…
  43. Mount Wilson Magnetic Classifications In solar-terrestrial terms, a classification system for sunspots: Alpha: Denotes a unipolar sunspot group.
  44. Mountain Wave The wavelike effect, characterized by updrafts and downdrafts, that occurs above and behind a mountain range when rapidly flowing air encounters the…
  45. Mountain Wind System The system of diurnal winds that forms in a complex terrain area, consisting of mountain-plain, along-valley, cross-valley and slope wind systems.
  46. Mountain-Plain Wind System A closed, large-scale, thermally driven circulation between the mountains and the surrounding plain.
  47. Mountainado A vertical-axis eddy produced in a downslope windstorm by the vertical stretching of horizontal roll vortices produced near the ground by vertical wind…
  48. MOV Move
  49. Movable Bed A stream bed made up of materials readily transportable by the stream flow.
  50. MOVG moving
  51. MR more
  52. MRF Medium Range Forecast model, the medium-range computer model run by the United States (NOAA).
  53. MRGL Marginal
  54. MRNG Morning
  55. MSG Message
  56. MSL (Mean Sea Level) - The arithmetic mean of hourly water elevations observed over a specific 19-year tidal epoch.
  57. MSLP Mean sea level pressure
  58. MST Mountain Standard Time
  59. MSTLY Mostly
  60. MSTR Moisture
  61. MT Main Tank
  62. MTN Mountain
  63. MTNS Mountains
  64. MTS Mountains
  65. Mud Slide Fast moving soil, rocks and water that flow down mountain slopes and canyons during a heavy downpour of rain.
  66. Muggy A subjective term for warm and excessively humid conditions.
  67. MULI Most Unstable Lifted Index - Lifted Index (LI) calculated using a parcel from the pressure level that results in the Most Unstable value (lowest value) of…
  68. Multicell Thunderstorm These thunderstorms are organized in clusters of at least 2-4 short-lived cells.
  69. Multiple Doppler Analysis The use of more than one radar (and hence more than one look angle) to reconstruct spatial distributions of the 2D or 3D wind field, which cannot be…
  70. Multiple Vortex Tornado A tornado in which two or more condensation funnels or debris clouds are present at the same time, often rotating about a common center or about each…
  71. Multipurpose Reservoir A reservoir constructed and equipped to provide storage and release of water for two or more purposes such as flood control, power development…
  72. Municipal Solid Waste (MSW) (MSW) Waste material from households and businesses in a community that is not regulated as hazardous.
  73. Municipal Use of Water The various uses of water in developed urban areas, including domestic use, industrial use, street sprinkling, fire protection, etc.
  74. Mushroom Slang for a thunderstorm with a well-defined anvil rollover, and thus having a visual appearance resembling a mushroom.
  75. MVFR Marginal Visual Flight Rules - in an aviation product, refers to the general weather conditions pilots can expect at the surface.
  76. MVS Moves
  77. MWD On a buoy report, mean wave direction corresponding to energy of the dominant period (DOMPD).
  78. MWS Marine Weather Statement
  79. N North
  80. Nacreous Clouds Clouds of unknown composition that have a soft, pearly luster and that form at altitudes about 25 to 30 km above the Earth's surface.
  81. NADIR The point on any given observer's celestial sphere diametrically opposite of one's zenith.
  82. NAM The operational North American Meso (NAM, formerly Eta) is run four times per day (00,06,12,18Z), all cycles run to 84-h.
  83. Nanotesla (nT) A unit of magnetism equal to 10-9 tesla, equivalent to a gamma (10-5 gauss).
  84. NAO North Atlantic Oscillation - the NAO is a large-scale fluctuation in atmospheric pressure between the subtropical high pressure system located near the…
  85. NAO Index This index measures the anomalies in sea level pressure between the Icelandic low pressure system and the Azores high pressure system in the North…
  86. Naphtha A generic term applied to a petroleum fraction with an approximate boiling range between 122 and 400 degrees Fahrenheit.
  87. National Ambient Air Quality Standards In the United States, national standards for the ambient concentrations in air of different air pollutants designed to protect human health and welfare.
  88. National Climatic Data Center The agency that archives climatic data from the National Oceanic and Atmospheric Administration, as well as other climatological organizations.
  89. National Digital Forecast Database (NDFD)- The National Weather Service's NDFD provides access to gridded forecasts of sensible weather elements (e.g.
  90. National Fire Danger Rating System A uniform fire danger rating system used in the United States that focuses on the environmental factors that impact the moisture content of fuels.
  91. National Flood Summary This NWS daily product (abbreviated FLN) contains nationwide information on current flood conditions.
  92. National Geodetic Vertical Datum (NGVD) of 1929 [NGVD 1929] (NGVD) A fixed reference adopted as a standard geodetic datum for elevations determined by leveling.
  93. National Hurricane Center One of three branches of the Tropical Prediction Center (TPC). This center maintains a continuous watch on tropical cyclones over the Atlantic, Caribbean…
  94. National Hurricane Operations Plan (NHOP) - The NHOP is issued annually by the Federal Coordinator for Meteorological Services and Supporting Research.
  95. National Severe Storms Laboratory This is one of NOAA's internationally known Environmental Research Laboratories, leading the way in investigations of all aspects of severe weather.
  96. National Weather and Crop Summary A product of the National Agricultural Statistics Service, Agricultural Statistics Board, and U.S. Department of Agriculture.
  97. Natural Control A stream gaging control which is natural to the stream channel, in contrast to an artificial control structure by man.
  98. Natural gas A hydrocarbon gas obtained from underground sources, often in association with petroleum and coal deposits.
  99. Natural gas liquids (NGLs) Those hydrocarbons in natural gas that are separated as liquids from the gas. Includes natural gas plant liquids and lease condensate.
  100. Nautical Dawn The time at which the sun is 12 degrees below the horizon in the morning. Nautical dawn is defined as that time at which there is just enough sunlight for…

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