ClimateThe prevailing or average weather conditions of a geographic region.
Climate ChangeA term used to describe short and long-term affects on the Earth's climate as a result of human activities such as fossil fuel combustion and vegetation…
Climate Diagnostics Bulletin(CDB) - The monthly CPC Bulletin reports on the previous months' status of the ocean-atmosphere climate system and provides various seasonal ENSO-related…
Climate Diagnostics Center(CDC) - The mission of NOAA's Climate Diagnostics Center is to identify the nature and causes for climate variations on time scales ranging from a month…
Climate FeedbackAn interaction mechanism between processes in the climate system is called a climate feedback, when the result of an initial process triggers changes in a…
Climate LagThe delay that occurs in climate change as a result of some factor that changes only very slowly.
Climate ModelMathematical model for quantitatively describing, simulating, and analyzing the interactions between the atmosphere and underlying surface (e.g.
Climate modelingThe simulation of the climate using computer-based models. See climate model, General Circulation Model.
Climate OutlookA climate outlook issued by the CPC gives probabilities that conditions, averaged over a specified period, will be below-normal, normal, or above-normal.
Climate Prediction CenterThis Center is one of several centers under the National Centers for Environmental Prediction (NCEP) part of the National Weather Service (NWS) in the…
Climate SensitivityIn IPCC Reports, equilibrium climate sensitivity refers to the equilibrium change in global mean surface temperature following a doubling of the…
Climate SystemThe system consisting of the atmosphere (gases), hydrosphere (water), lithosphere (solid rocky part of the Earth), and biosphere (living) that determine…
Climate System (or Earth System)The five physical components (atmosphere, hydrosphere, cryosphere, lithosphere, and biosphere) that are responsible for the climate and its variations.
Climate variabilityClimate (climatic) variability 1)In the most general sense, the term "climate variability" denotes the inherent characteristic of climate which manifests…
Climatological atlasClimatological atlas Atlas composed mainly of climatological charts. It represents especially the monthly and annual distributions of the principal…
Climatological OutlookAn outlook based upon climatological statistics for a region, abbreviated as CL on seasonal outlook maps.
ClimatologyThe science that deals with the phenomena of climates or climatic conditions.
ClimometerAn instrument that measures angles of inclination; used to measure cloud ceiling heights.
Closed BasinA basin draining to some depression or a pond within its area, from which water is lost only by evaporation or percolation.
Closed Basin Lake FloodingFlooding that occurs on lakes with either no outlet or a relatively small one. Seasonal increases in rainfall cause the lake level to rise faster than it…
Closed LowA low pressure area with a distinct center of cyclonic circulation which can be completely encircled by one or more isobars or height contour lines.
CloudA claim to the title of a property that, if valid, would prevent a purchaser from obtaining a clear title.
Cloud amountCloud amount (cover) That portion of the sky cover which is attributed to clouds.
cloud base heightFor a given cloud or cloud layer, the lowest level of the atmosphere where cloud properties are detectable.
Cloud CeilingSame as Ceiling; the height of the cloud base for the lowest broken or overcast cloud layer.
Cloud Condensation NucleiSmall particles in the air on which water vapor condenses and forms cloud droplets.
cloud condensation nucleusA particle, either liquid or solid, upon which water condenses to form cloud droplets.
cloud coverThe amount of the sky obscured by clouds when observed at a particular location.
cloud deckThe top of a cloud layer, usually viewed from an aircraft.
cloud fractionFraction of sky covered by clouds, observed directly or derived from SW irradiance.
cloud ice waterThe concentration (mass/vol) of ice water particles in a cloud.
Cloud LayerAn array of clouds whose bases are at approximately the same level.
cloud liquid waterThe concentration (mass/vol) of liquid water droplets in a cloud.
Cloud MovementThe direction toward which a cloud is moving
Cloud StreetsRows of cumulus or cumulus-type clouds aligned parallel to the low-level flow. Cloud streets sometimes can be seen from the ground, but are seen best on…
Cloud TagsRagged, detached cloud fragments; fractus or scud.
cloud top heightFor a given cloud or cloud layer, the highest level of the atmosphere where cloud properties are detectable.
CloudyWhen 7/8ths or more of the sky is covered by clouds.
Co-BenefitThe benefits of policies that are implemented for various reasons at the same time – including climate change mitigation – acknowledging that most…
Co-control benefitThe additional benefit derived from an environmental policy that is designed to control one type of pollution, while reducing the emissions of other…
CoalA black or brownish black solid, combustible substance formed by the partial decomposition of vegetable matter without access to air.
Coal cokeA hard, porous product made from baking bituminous coal in ovens at temperatures as high as 2,000 degrees Fahrenheit.
Coal gasificationConversion of solid coal to synthetic natural gas (SNG) or a gaseous mixture that can be burned as a fuel.
Coal liquefactionConversion of solid coal to a liquid fuel such as synthetic crude oil or methanol.
Coal Mine MethaneCoal mine methane is the subset of CBM that is released from the coal seams during the process of coal mining.
Coalbed methaneA methane-rich gas, similar to natural gas, produced from in-situ coal through drilled wells that are typically completed open-hole, as opposed to the…
CoalescenceThe process by which water droplets in a cloud collide and come together to form raindrops.
Coastal WatersIn the Great Lakes region, the waters within the territorial jurisdiction of the United States consisting of the Great Lakes, their connecting waters…
Coastal Waters Forecast (CWF)The marine forecast for areas, including bays, harbors, and sounds, from a line approximating the mean high water mark (average height of high water over…
Coastal/Lakeshore Flood AdvisoryMinor flooding is possible (i.e., over and above normal high tide levels. Coastal/Lakeshore Flood Advisories are issued using the Coastal/Lakeshore Hazard…
Coastal/Lakeshore Flood WarningFlooding that will pose a serious threat to life and property is occurring, imminent or highly likely.
Coastal/Lakeshore Flood WatchFlooding with significant impacts is possible. Coastal/Lakeshore Flood Watches are issued using the Coastal/Lakeshore Hazard Message (CFW) product.
Coastal/Lakeshore Flooding(i) (Oceanic) Coastal Flooding is the inundation of land areas adjacent to bodies of salt water connected to the Atlantic Ocean, Pacific Ocean, or Gulf of…
CogenerationThe generation of electricity or shaft power by an energy conversion system and the concurrent use of rejected thermal energy from the conversion system…
Coherent RadarA radar that utilizes both signal phase and amplitude to determine target characteristics.
Cold AdvectionTransport of cold air into a region by horizontal winds.
Cold Air AvalancheDownslope flow pulsations that occur at more or less regular intervals as cold air builds up on a peak or plateau, reaches a critical mass, and then…
Cold Air DamA shallow cold air mass which is carried up the slope of a mountain barrier, but with insufficient strength to surmount the barrier.
Cold Air Damming (CAD)The phenomenon in which a low-level cold air mass is trapped topographically. Often, this cold air is entrenched on the east side of mountainous terrain.
Cold Air FunnelA funnel cloud or (rarely) a small, relatively weak tornado that can develop from a small shower or thunderstorm when the air aloft is unusually cold…
cold frontA weather condition accompanied by high, clear skies, and a sudden drop in temperature.
Cold lowCold low (or cold cyclone) At a given level in the atmosphere, any low that is generally characterized by colder air near its center than around its…
Cold OcclusionA frontal zone formed when a cold front overtakes a warm front and, being colder than the air ahead of the warm front, slides under the warm front…
Cold PoolA region of relatively cold air, represented on a weather map analysis as a relative minimum in temperature surrounded by closed isotherms.
collaborating programA program joining with the ARM Program to pursue a specific set of objectives by providing resources and participating in active planning and execution of…
Collar CloudA generally circular ring of cloud that may be observed on rare occasions surrounding the upper part of a wall cloud.
Collection EfficiencyThe fraction of droplets approaching a surface that actually deposit on that surface.
Colorado LowA low pressure storm system that forms in winter in southeastern Colorado or northeastern New Mexico and tracks northeastward across the central plains of…
Columnar IceIce consisting of columnar shaped grain. The ordinary black ice is usually columnar-grained.
Combined SeasCombination of both wind waves and swell. Also called "Seas" and is approximately equal to significant wave height.
CombustionThe process of burning; the oxidation of a material by applying heat, which unites oxygen with a material or fuel.
Comma CloudA synoptic scale cloud pattern with a characteristic comma-like shape, often seen on satellite photographs associated with large and intense low-pressure…
Comma EchoA thunderstorm radar echo which has a comma-like shape. It often appears during latter stages in the life cycle of a bow echo
Commercial SectorConsists of businesses that are not engaged in transportation or manufacturing or other types of industrial activities.
Complex Gale/StormIn the high seas and offshore forecasts, an area for which gale/storm force winds are forecast or are occurring but for which no single center is the…
Complex TerrainTypically used to refer to mountainous terrain. In general usage, it may also refer to coastal regions and heterogeneous landscapes.
CompositeAn average that is calculated according to specific criteria. For example, one might want a composite for the rainfall at a given location for all years…
Composite HydrographA stream discharge hydrograph which includes base flow, or one which corresponds to a net rain storm of duration longer than one unit period.
CompostPartially decomposed organic plant and animal matter that can be used as a soil conditioner or fertilizer. See decomposition.
CompostingThe process of degrading organic material (biomass) by microorganisms in aerobic conditions.
Compound(KOM-pownd) In science, a substance that is made up of more than one ingredient.
CondensationThe process by which water in air changes from a vapor to a liquid due to a change in temperature or pressure; occurs when water vapor reaches its dew…