Weather terms starting with M

219 terms

  1. Meteoric Water Water derived from precipitation.
  2. Meteorological element Meteorological element Any one of the properties or conditions of the atmosphere which together specify the weather at a given place for any particular…
  3. Meteorologist A person who studies meteorology. There are many different paths within the field of meteorology.
  4. Meteorology The science dealing with the atmosphere and its phenomena. A distinction can be drawn between meteorology and climatology, the latter being primarily…
  5. Methane (CH4) A hydrocarbon that is a greenhouse gas with a global warming potential most recently estimated at 23 times that of carbon dioxide (CO2).
  6. Methane (CH<sub>4</sub>) A hydrocarbon that is a greenhouse gas with a global warming potential most recently estimated at 21.
  7. Methanol (CH<sub>3</sub>3OH) A colorless poisonous liquid with essentially no odor and little taste. It is the simplest alcohol with a boiling point of 64.7 degrees Celsius.
  8. Methanotrophic Having the biological capacity to oxidize methane to CO2 and water by metabolism under aerobic conditions. See aerobic.
  9. Methyl bromide (CH<sub>3</sub>Br) An effective pesticide; used to fumigate soil and many agricultural products. Because it contains bromine, it depletes stratospheric ozone when released…
  10. Metric Ton (or tonne) 1000 kilograms. 1 metric ton = 2,204.62 lb = 1.023 short tons.
  11. METRO Metropolitan
  12. MeV One million electron volts.
  13. MEX 1) GFS Model Guidance 2) Mexico
  14. MI 1) Mile 2) Michigan
  15. MIC Meteorologist In Charge
  16. Microbarograph A instrument designed to continuously record a barometer's reading of very small changes in atmospheric pressure.
  17. Microburst A convective downdraft with an affected outflow area of less than 2½ miles wide and peak winds lasting less than 5 minutes.
  18. Microclimate The local climate of specific place or habitat, as influenced by landscape features.
  19. Micron One thousandth of a millimeter.
  20. Microscale Pertaining to meteorological phenomena, such as wind circulations or cloud patterns, that are less than 2 km in horizontal extent.
  21. Microwave A type of electromagnetic radiation with wavelengths between those of infrared radiation and radio waves.
  22. Microwave Burst In solar-terrestrial terms, a radiowave signal associated with optical and/or X-ray flares
  23. microwave radiation Electromagnetic radiation generally in the frequency range between 300 MHz and 300 GHz (wavelengths between 1mm and 1m).
  24. MID Middle
  25. Mid-Flame Wind Wind measured at the midpoint of the flames, considered to be most representative of the speed of the wind that is affecting fire behavior.
  26. Mid-Latitude Areas Areas between 30o and 60o north and south of the Equator.
  27. Mid-level Cooling Local cooling of the air in middle levels of the atmosphere (roughly 8 to 25 thousand feet), which can lead to destabilization of the entire atmosphere if…
  28. Middle Clouds (or Mid-Level Clouds) - A term used to signify clouds with bases between 6,500 and 23,000 feet.
  29. Middle Latitudes 1) The latitude belt roughly between 35 and 65 degrees North and South. Also referred to as the temperate region.
  30. Middle-level clouds Middle-level clouds (Ac and As) Altocumulus and Altostratus are the middle-level clouds.
  31. Mie Scattering Any scattering produced by spherical particles whose diameters are greater than 1/10 the wavelength of the scattered radiation.
  32. Millibar A unit of atmospheric pressure equal to 1/1000 bar, or 1000 dynes per square centimeter.
  33. MIN Minimum (or) Minute
  34. Mineral A nutrient required to maintain health.
  35. Minimum Discernible Signal In a receiver, it is the smallest input signal that will a produce a detectable signal at the output.
  36. Minimum Temperature This is the lowest temperature recorded during a specified period of time. The time period can be 6, 12 or 24 hours.
  37. Minor Flooding A general term indicating minimal or no property damage but possibly some public inconvenience.
  38. Minor Tidal Overflow Minor flooding caused by high tides that results in little if any damage.
  39. MINT minimum temperature
  40. MISC Miscellaneous
  41. MISG Missing
  42. Misoscale The scale of meteorological phenomena that ranges in size from 40 meters to about 4 kilometers. It includes rotation within a thunderstorm.
  43. 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…
  44. Mixed Layer An atmospheric layer, usually the layer immediately above the ground, in which pollutants are well mixed by convective or shear-produced turbulence.
  45. 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.
  46. 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…
  47. 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.
  48. 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.
  49. MJO Madden-Julian Oscillation- Tropical rainfall exhibits strong variability on time scales shorter than the seasonal El Niño-Southern Oscillation (ENSO).
  50. 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.
  51. 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…
  52. 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.
  53. MLW (Mean Low Water) - A tidal datum. The average of all the low water heights observed over the National Tidal Datum Epoch.
  54. MNLY Mainly
  55. Mobile Facility The ARM Mobile Facility (AMF) was first deployed in 2005; it consists of large shipping containers converted into laboratories.
  56. MOBY Marine Optical Buoy. It measures solar radiation to calibrate satellite ocean color instruments.
  57. model See Exhibit.
  58. 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…
  59. 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.
  60. Moderate Flooding The inundation of secondary roads; transfer to higher elevation necessary to save property -- some evacuation may be required.
  61. Moderate Risk (of severe thunderstorms) Severe thunderstorms are expected to affect between 5 and 10 percent of the area.
  62. 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.
  63. 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.
  64. moist adiabatic lapse rate (MALR) The rate at which the temperature of a parcel of saturated air decreases as the parcel is lifted in the atmosphere.
  65. Moist-adiabatic (Also known as saturation-adiabatic process.) An adiabatic process for which the air is saturated and may contain liquid water.
  66. Moisture The amount of water and other components present in the biomass sample that are volatilized at 105°C. (Source: Ehrman, T.
  67. Moisture Advection Transport of moisture by horizontal winds.
  68. 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.
  69. 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)…
  70. Moisture Ridge An axis of relatively high dew point values. This axis is sometimes referred to as a 'moist tongue'.
  71. 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.
  72. Monitor Stage The stage which, when reached by a rising stream, represents the level where appropriate officials (e.g.
  73. Monostatic Radar A radar that uses a common antenna for both transmitting and receiving.
  74. Monsoon A thermally driven wind arising from differential heating between a land mass and the adjacent ocean that reverses its direction seasonally.
  75. 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.
  76. 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.
  77. Morning Glory An elongated cloud band, visually similar to a roll cloud, usually appearing in the morning hours, when the atmosphere is relatively stable.
  78. MOS Model Output Statistics - the Hydrometeorological Center (HPC) produces a short range (6 to 60 hours) MOS guidance package generated from the NGM, GFS…
  79. Mostly Clear When the 1/8th to 2/8ths of the sky is covered by with opaque (not transparent) clouds.
  80. Mostly Cloudy When the 6/8th to 7/8ths of the sky is covered by with opaque (not transparent) clouds. Same as Considerable Cloudiness .
  81. 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.
  82. Motor gasoline A complex mixture of relatively volatile hydrocarbons, with or without small quantities of additives, obtained by blending appropriate refinery streams to…
  83. 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…
  84. Mount Wilson Magnetic Classifications In solar-terrestrial terms, a classification system for sunspots: Alpha: Denotes a unipolar sunspot group.
  85. Mountain Wave The wavelike effect, characterized by updrafts and downdrafts, that occurs above and behind a mountain range when rapidly flowing air encounters the…
  86. 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.
  87. Mountain-Plain Wind System A closed, large-scale, thermally driven circulation between the mountains and the surrounding plain.
  88. 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…
  89. MOV Move
  90. Movable Bed A stream bed made up of materials readily transportable by the stream flow.
  91. MOVG moving
  92. MR more
  93. MRF Medium Range Forecast model, the medium-range computer model run by the United States (NOAA).
  94. MRGL Marginal
  95. MRNG Morning
  96. MSG Message
  97. MSL (Mean Sea Level) - The arithmetic mean of hourly water elevations observed over a specific 19-year tidal epoch.
  98. MSLP Mean sea level pressure
  99. MST Mountain Standard Time
  100. MSTLY Mostly