Meteorology and atmospheric science terminology · MLC-0110

Meteorology and atmospheric science terms: D (172)

• DDust
• Daily Climatological ReportAs the name indicates, this climatological product is issued daily by each National Weather Service office...
• Daily Flood PeakIn hydrologic terms, the maximum mean daily discharge occuring in a stream during a given flood event.
• DALRDry Adiabatic Lapse Rate
• DamIn hydrologic terms, any artificial barrier which impounds or diverts water. The dam is generally...
• Dam FailureIn hydrologic terms, catastrophic event characterized by the sudden, rapid, and uncontrolled release of...
• DAMBRKIn hydrologic terms, the Dam Break Forecasting Model.
• DAPMIn hydrologic terms, the Data Acquisition Program Manager.
• Dark Surge on DiskIn solar-terrestrial terms, dark gaseous ejections visible in H-alpha.
• dart leaderA faint, negatively charged channel that travels more or less directly and continuously from cloud to ground.
• Data PointIn the context of hydrologic observations, a location on a river/stream for which observed data is input to...
• DATACOLIn hydrologic terms, the Software System that supports RFC gateway functions.
• DATANETIn hydrologic terms, it is the hydrologic Data Network Analysis Software.
• dawnSame as Civil Dawn; the time of morning at which the sun is 6 degrees below the horizon. At this time, there...
• Day LengthDuration of the period from sunrise to sunset.
• dBZNondimensional "unit" of radar reflectivity which represents a logarithmic power ratio (in decibels, or dB)...
• DCP(Data Collection Platform) In hydrologic terms, an electronic device that connects to a river or rainfall...
• DDSData Distribution System.
• Dead StorageIn hydrologic terms, the volume in a reservoir below the lowest controllable level.
• Debris CloudA rotating "cloud" of dust or debris, near or on the ground, often appearing beneath a condensation funnel...
• DecadalOccurring over a 10-year period, such as an oscillation whose period is roughly 10 years ("Pacific Decadal...
• declinationThe latitude that the sun is directly over at a given time. The declination is ~23°N at the summer solstice...
• Deep Percolation LossIn hydrologic terms, water that percolates downward through the soil beyond the reach of plant roots.
• Deep SeepageIn hydrologic terms, infiltration which reaches the water table.
• deep wellIn hydrologic terms, a well whose pumping head is too great to permit use of a suction pump.
• deepeningA decrease in the central pressure of a surface low pressure system. The storm is intensifying.
• deformation zoneThe change in shape of a fluid mass by variations in wind, specifically by stretching and/or shearing...
• deformed iceIn hydrologic terms, a general term for ice which has been squeezed together and forced upwards and downwards...
• degradationIn hydrologic terms, the geologic process by means of which various parts of the surface of the earth are...
• Degree-dayA measure that gauges the amount of heating or cooling needed for a building using 65 degrees as a baseline...
• DeltaIn hydrologic terms, an alluvial deposit, often in the shape of the Greek letter "delta", which is formed...
• Delta TChange in temperature.
• DendritesIn hydrologic terms, thin branch-like growth of ice on the water surface.
• DendriticIn hydrologic terms, the form of the drainage pattern of a stream and it's tributaries when it follows a...
• Dense Fog AdvisoryThis product is issued when fog reduces visibility to 1/4 mile or less over a widespread area. For marine...
• Dense Smoke AdvisoryThis product is issued for widespread or localized smoke reducing visibilities to ¼ mile or less.
• density currentIn hydrologic terms, a flow of water maintained by gravity through a large body of water, such as a reservoir...
• density of snowIn hydrologic terms, the ratio, expressed as a percentage, of the volume which a given quantity of snow would...
• DEPDeparture
• depletion curveIn hydrologic terms, the part of the hydrograph extending from the point of termination of the Recession...
• depressionA region of low atmospheric pressure that is usually accompanied by low clouds and precipitation. The term is...
• depression storageIn hydrologic terms, the volume of water contained in natural depressions in the land surface, such as...
• depth of runoffIn hydrologic terms, the total runoff from a drainage basin, divided by its area. For convenience in...
• Derecho(Pronounced day-RAY-cho), a widespread and usually fast-moving windstorm associated with convection. Derechos...
• Derived ProductsProcessed base data on the Doppler radar.
• desertificationA tendency toward more prominent desert conditions in a region.
• Design CriteriaIn hydrologic terms, the hypothetical flood used in the sizing of the dam and the associated structures to...
• Detention BasinsStructures built upstream from populated areas to prevent runoff and/or debris flows from causing property...
• detention storageIn hydrologic terms, the volume of water, other than depression storage, existing on the land surface as...
• DetritusIn hydrologic terms, (1) the heavier mineral debris moved by natural watercourses, usually in bed-load form...
• Developing Gale/StormIn the high seas and offshore forecasts, a headline used in the warnings section to indicate that gale/storm...
• dewMoisture that has condensed on objects near the ground, whose temperatures have fallen below the dewpoint...
• Dew Point(Abbrev. DWPT) - A measure of atmospheric moisture. It is the temperature to which air must be cooled in...
• Dew Point DepressionThe difference in degrees between the air temperature and the dew point.
• Dew Point FrontA narrow zone (mesoscale feature) of extremely sharp moisture gradient and little temperature gradient. It...
• DEWPOn a buoy report, the dewpoint temperature taken at the same height as the air temperature measurement.
• DFUSDiffuse
• DiabaticA process which occurs with the addition or loss of heat. The opposite of adiabatic. Meteorological examples...
• Diablo WindSimilar to Santa Ana winds in southern California. These winds occur below canyons in the East Bay hills...
• Diagnostic ModelA computer model used to calculate air pollution concentrations. A diagnostic model produces a wind field...
• diamond dustA fall of non-branched (snow crystals are branched) ice crystals in the form of needles, columns, or plates.
• Differential MotionCloud motion that appears to differ relative to other nearby cloud elements, e.g. clouds moving from left to...
• Differential RotationIn solar-terrestrial terms, the change in solar rotation rate with latitude. Low latitudes rotate at a faster...
• Diffuse IceIn hydrologic terms, poorly defined ice edge limiting an area of dispersed ice; usually on the leeward side...
• Difluence(or diffluence) - A pattern of wind flow in which air moves outward (in a "fan-out" pattern) away from a...
• DIR1. Direction
• Direct Flood DamageIn hydrologic terms, the damage done to property, structures, goods, etc., by a flood as measured by the cost...
• Direct HitA close approach of a tropical cyclone to a particular location. For locations on the left-hand side of a...
• direct runoffIn hydrologic terms, the runoff entering stream channels promptly after rainfall or snowmelt. Superposed on...
• direct solar radiationThe component of solar radiation received by the earth's surface only from the direction of the sun's disk...
• Directional ShearThe component of wind shear which is due to a change in wind direction with height, e.g., southeasterly winds...
• Disappearing Solar FilamentIn solar-terrestrial terms, the sudden (timescale of minutes to hours) disappearance of a solar filament...
• dischargeIn hydrologic terms, the rate at which water passes a given point. Discharge is expressed in a volume per...
• Discharge CurveIn hydrologic terms, a curve that expresses the relation between the discharge of a stream or open conduit at...
• Discharge TableIn hydrologic terms,
• disdrometerEquipment that measures and records the size distribution of raindrops.
• DiskThe visible surface of the sun (or any heavenly body) projected against the sky.
• dispersionThe process of separating radiation into various wavelengths.
• Distribution (Hydro)GraphIn hydrologic terms, a unit hydrograph of direct runoff modified to show the proportions of the volume of...
• DiurnalDaily; related to actions which are completed in the course of a calendar day, and which typically recur...
• Diurnal CyclesVariations in meteorological parameters such as temperature and relative humidity over the course of a day...
• Diurnal Temperature RangeThe temperature difference between the minimum at night (low) and the maximum during the day (high).
• divergenceThe expansion or spreading out of a vector field; usually said of horizontal winds. It is the opposite of...
• DiversionIn hydrologic terms, the taking of water from a stream or other body of water into a canal, pipe, or other...
• divideIn hydrologic terms, the high ground that forms the boundary of a watershed. A divide is also called a ridge.
• dividing streamlineIn the blocked flow region upwind of a mountain barrier, the streamline that separates the blocked flow...
• Dividing Streamline HeightThe height above ground of the dividing streamline, as measured far upwind of a mountain barrier. See...
• DMNTDominant
• DMSHDiminish
• DNRDepartment of Natural Resources
• DNSDense
• DNSTRMDownstream
• Dobson unitUnit used to measure the abundance of ozone in the atmosphere. One Dobson unit is the equivalent of 2.69/ x...
• DOCDepartment of Commerce
• DOHDevelopment and Operations Hydrologist
• doldrumsThe regions on either side of the equator where air pressure is low and winds are light.
• domainIn air pollution modeling, the geographical area over which a simulation is performed.
• Domestic ConsumptionIn hydrologic terms, the quantity, or quantity per capita, of water consumed in a municipality or district...
• Domestic Use of waterIn hydrologic terms, the use of water primarily for household purposes, the watering of livestock, the...
• Doppler radarRadar that can measure radial velocity, the instantaneous component of motion parallel to the radar beam...
• DownburstA strong downdraft current of air from a cumulonimbus cloud, often associated with intense thunderstorms...
• downdraft(Abbrev. DWNDFT) - A small-scale column of air that rapidly sinks toward the ground, usually accompanied by...
• Downslope FlowA thermally driven wind directed down a mountain slope and usually occurring at night; part of the...
• downstreamIn the same direction as a stream or other flow, or toward the direction in which the flow is moving.
• Downstream SlopeIn hydrologic terms, the slope or face of the dam away from the reservoir water. This slope requires some...
• Down-Valley WindA thermally driven wind directed down a valley's axis, usually occurring during nighttime; part of the...
• downwashA deflection of air downward relative to an object that causes the deflection.
• Downwelling RadiationThe component of radiation directed toward the earth's surface from the sun or the atmosphere, opposite of...
• DP1. Deep
• DPDOn a buoy report, dominant wave period (seconds) is the period with the maximum wave energy.
• DPNGDeepening
• DPTHDepth
• DPTRDeparture
• DPVADifferential Positive Vorticity Advection
• DRDirection
• drainage areaIn hydrologic terms, an area having a common outlet for its surface runoff (also see Watershed and Catchment...
• drainage basinIn hydrologic terms, a part of the surface of the earth that is occupied by a drainage system, which consists...
• drainage densityIn hydrologic terms, the relative density of natural drainage channels in a given area. It is usually...
• drainage divideIn hydrologic terms, the boundary line, along a topographic ridge or along a subsurface formation, separating...
• DrainerA valley or basin from which air drains continuously during nighttime rather than becoming trapped or pooled.
• Drains (Relief Wells)In hydrologic terms, a vertical well or borehole, usually downstream of impervious cores, grout curtains or...
• drawdownIn hydrologic terms, the lowering of the surface elevation of a body of water, the water surface of a well...
• DRCTNDirection
• DredgingIn hydrologic terms, the scooping, or suction of underwater material from a harbor, or waterway. Dredging is...
• D-regionIn solar-terrestrial terms, a daytime layer of the earth's ionosphere approximately 50 to 90 km in altitude.
• DRFTDrift
• Drifting IceIn hydrologic terms, pieces of floating ice moving under the action of wind and/ or currents.
• drifting snowDrifting snow is an uneven distribution of snowfall/snow depth caused by strong surface winds. Drifting snow...
• DrizzlePrecipitation consisting of numerous minute droplets of water less than 0.5 mm (500 micrometers) in diameter.
• drop-size distributionThe distribution of rain drops or cloud droplets of specified sizes.
• DroughtDrought is a deficiency of moisture that results in adverse impacts on people, animals, or vegetation over a...
• Drought AssessmentsAt the end of each month, CPC issues a long-term seasonal drought assessment. On Thursdays of each week, the...
• drought indexIn hydrologic terms, computed value which is related to some of the cumulative effects of a prolonged and...
• dry adiabatA line of constant potential temperature on a thermodynamic chart.
• Dry Adiabatic Lapse RateThe rate at which the temperature of a parcel of dry air decreases as the parcel is lifted in the atmosphere...
• Dry CrackIn hydrologic terms, a crack visible at the surface but not going right through the ice cover, and therefore...
• Dry FloodproofingIn hydrologic terms, a dry floodproofed building is sealed against floodwaters. All areas below the flood...
• Dry LineA boundary separating moist and dry air masses, and an important factor in severe weather frequency in the...
• Dry Line BulgeA bulge in the dry line, representing the area where dry air is advancing most strongly at lower levels...
• Dry Line StormAny thunderstorm that develops on or near a dry line.
• Dry MicroburstA microburst with little or no precipitation reaching the ground; most common in semi-arid regions. They may...
• Dry Punch[Slang], a surge of drier air; normally a synoptic-scale or mesoscale process. A dry punch at the surface...
• Dry SlotA zone of dry (and relatively cloud-free) air which wraps east- or northeastward into the southern and...
• Dry ThunderstormGenerally a high-based thunderstorm when lightning is observed, but little if any precipitation reaches the...
• Dry Weather FlowIn hydrologic terms, streamflow which results from precipitation that infiltrates into the soil and...
• Dry-adiabatic1. An adiabatic process in a hypothetical atmosphere in which no moisture is present. 2. An adiabatic process...
• DSASpecial Tropical Disturbance Statement
• DSIPTDissipate
• Dst IndexA geomagnetic index describing variations in the equatorial ringcurrent
• DTRTDeteriorate
• duration curveIn hydrologic terms, a cumulative frequency curve that shows the percent of time during which specified units...
• Duration of Ice CoverIn hydrologic terms, The time from freeze-up to break-up of an ice cover.
• Duration of SunshineThe amount of time sunlight was detected at a given point.
• DURGDuring
• DURNDuration
• duskSame as Civil Dusk; the time at which the sun is 6 degrees below the horizon in the evening. At this time...
• Dust AdvisoryThis product is issued when convectively-driven dust is reducing visibilities to 1 mile or less, but greater...
• Dust devilA small, rapidly rotating wind that is made visible by the dust, dirt or debris it picks up. Also called a...
• Dust PlumeA non-rotating "cloud" of dust raised by straight-line winds. Often seen in a microburst or behind a gust...
• Dust StormA severe weather condition characterized by strong winds and dust-filled air over an extensive area.
• Dust Storm WarningThis product is issued when a convectively-driven dust storm is reducing visibilities to ¼ mile or less...
• dust whirlA rotating column of air rendered visible by dust.
• DVLPDevelop
• DVVDownward Vertical Velocity (sinking air)
• DWNDFTDowndraft - A small-scale column of air that rapidly sinks toward the ground, usually accompanied by...
• DWNSLPDownslope
• DWPTDew Point - A measure of atmospheric moisture. It is the temperature to which air must be cooled in order to...
• Dynamic IceIn hydrologic terms, pressure due to a moving ice cover or drifting ice. Pressure occuring at movement of...
• Dynamic LiftingThe forced uplifting of air from various atmospheric processes, such as weather fronts, and cyclones.
• Dynamic Wave Routing ModelA computerized hydraulic routing program whose algorithms incorporate the complete one-dimensional equations...
• DynamicsGenerally, any forces that produce motion or effect change. In operational meteorology, dynamics usually...
• DZDrizzle

172 of 3,164 terms in Meteorology and atmospheric science terminology (MLC-0110). Request the full dataset.