Aviation Meteorological Information Definition

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2023-

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EUROCONTROL

swim@eurocontrol.int

author

The information definition covers the elements used by the various Meteorological SWIM services.

tbd

EntityCollection

A collection of entities.

Report

relativeLocation

Entity: Aerodrome or Airspace or State

The location of an entity expressed in relation to another entity.

TAF.aerodrome

F

source

CharacterString

Name of entity or organisation that supplied data.

Unit

name

designator

type

position

GM_Point

The geometry of the entity expressed as the position of a point on the surface of the Earth.

endValidity

DateTime

Date and time at which the data contained in the entity state ceases to be effective.

TAF.validPeriod.endPosition

F

startValidity

DateTime

Date and time at which the data contained in the entity state starts to be effective.

TAF.validPeriod.beginPosition

F

lastRevision

DateTime

Date and time when the data was last revised.

O

member

Entity: WeatherPhenomenon or WeatherCondition 0..*

An entity that is member of the collection.

Aerodrome

Aerodrome

A defined area on land or water (including any buildings, installations and equipment) intended to be used either wholly or in part for the arrival, departure and surface movement of aircraft.

AirportHeliport

designator

CharacterString

Aerodrome.designator

Designator for an aerodrome.

designator

locationIndicatorICAO

CharacterString

Aerodrome.locationIndicatorICAO

A four-letter code group formulated in accordance with rules prescribed by ICAO and assigned to the aerodrome.

locationIndicatorICAO

designatorIATA

CharacterString

Aerodrome.designatorIATA

Identifier that is assigned to a location in accordance with rules (resolution 767) governed by the International Air Transport Association (IATA).

designatorIATA

name

CharacterString

Aerodrome.name

Primary official name of an aerodrome as designated by an appropriate authority.

name

fieldElevation

ValVerticalDistanceType

Aerodrome.fieldElevation

The vertical distance above Mean Sea Level (MSL) of the highest point of the landing area.

fieldElevation

aerodromeReferencePoint

InfrastructurePoint

Aerodrome.aerodromeReferencePoint

The designated geographical location of an aerodrome.

ARP

Airspace

Airspace

A defined three dimensional region of space relevant to air traffic.

Airspace

designator

CharacterString

Airspace.designator

Published sequence of characters allowing the identification of the airspace.

designator

name

CharacterString

Airspace.name

Name given to an airspace by a responsible authority.

name

type

CodeAirspaceType [0..1]

Airspace.

type

Indicator of the

general structure or characteristics of a particular airspace.

type

isDesignatorICAO

Boolean

Airspace.isDesignatorICAO

An indicator of whether an airspace designator is recorded in ICAO Doc. 7910 'Location Indicators'.

designatorICAO

geometryComponent

AirspaceVolume

Airspace.geometryComponent

A portion of airspace that contributes to the definition of the airspace geometry.

geometryComponent

State

State

An internationally recognized geographic entity that provides air traffic service.

icaoNationalityLetters

CharacterString [0..1]

State.icaoNationalityLetters

Nationality letters as defined by ICAO.

isoCountryCode

CharacterString [0..1]

State.isoCountryCode

Country codes as defined by ISO.

name

CharacterString

State.name

Full official name of the state.

territory

CharacterString [0..1]

State.territory

Name of the territory within the state.

WeatherCondition

Weather observations or forecast for an area of interest.

Note: This is the root for the various aviation conditions: AerodromeCondition.

analysisTime

DateTime

The time at which the forecast or observation process starts.

changeIndicator

CodeChangeIndicatorType

Indication about the type of meteorological conditions changes.

confidence

Quality of trusting for a forecast expressed as a percentage.

hasNoSignificantWeather

Indication that no specified en-route weather phenomena which may affect the safety of aircraft operations is occurring or expected to occur.

probability

Relative likelihood of a forecast expressed as a percentage.

type

CodeWeatherConditionType

The type of weather condition being reported.

weatherInformationSource

WeatherInformationSource

The weather information source.

contour

Contour

A contour used to outline a particular weather situation within the forecast or observation.

phenomenon

WeatherPhenomenon

The phenomenon of relevance for the weather condition.

surfaceWind, cloud, etc.

Contour

An estimated or observed outline of a particular weather situation.

applicability: En-route significant weather only.

contourValue

Measure

The value of the measure that applies to that contour.
For example a pressure chart could have contours where each contour line represents a specific pressure value, this could be sorted in the contourValue.

AviationCondition

Weather observations and or forecast for a specific aeronautical location or airspace volume.

airPressure

Force per unit area exerted into a surface by the weight of air above that surface.

airTemperature

The temperature indicated by a thermometer exposed to the air in a place sheltered from direct solar radiation.

dewpointTemperature

The temperature to which a given air parcel must be cooled at constant pressure and constant water vapor content in order for saturation to occur.

maximumAirTemperature

The maximum air temperature.

maximumAirTemperatureTime

The time of the occurrence of the maximum air temperature.

minimumAirTemperature

The minimum air temperature.

minimumAirTemperatureTime

The time of the occurrence of the minimum air temperature.

relativeHumidity

At a given pressure and temperature, the percentage ratio of the gram-molecular weight of the water vapour to the gram-molecular weight that the air would have if it were saturated with respect to water at the same pressure and temperature.

verticalVisibility

Maximum distance at which an observer can see and identify an object on the same vertical as himself, above or below.

verticalVisibility

tropopause

Meteorological information about the tropopause.

ceiling

Meteorological information about the cloud ceiling.

horizontalVisibility

HorizontalVisibility

The greatest horizontal distance at which selected objects can be seen, identified, and/or measured with instrumentation.

AerodromeCondition

Weather observations and or forecast for an aerodrome

cavok

Boolean

Visibility, cloud and present weather better than prescribed values or conditions.

qfe

ValPressureType

Atmospheric pressure at aerodrome elevation. A pressure type altimeter calibrated in accordance with the Standard Atmosphere, when set to a QFE altimeter setting using this particular pressure value, will indicate the height above the aerodrome environment.

qnh

ValPressureType

Q Code corresponding to the derived atmospheric pressure at Mean Sea Level, based on the atmospheric pressure at the reference point converted using the characteristics of the ICAO Standard Atmosphere.

ValPressureType

Cloud

The cloud conditions at the aerodrome.

AirspaceCondition

Weather-related observations and forecasts of relevance to an airspace.

airspace

Airspace

The airspace which is subject to observation or forecast.

RouteCondition

Weather observations and / or forecasts related to routes.

route

Route

The route which is subject to observation or forecast.

RunwayCondition

qfe

Atmospheric pressure at runway threshold elevation. A pressure type altimeter calibrated in accordance with the Standard Atmosphere, when set to a QFE altimeter setting using this particular pressure value, will indicate the height above the touch-down zone of the runway.

temperature

The temperature measured by a probe under the runway surface at the touchdown (TDZ) zone.

rvr

RunwayVisualRange

The observed or forecast runway visual range.

runway

Runway

The runway which is subject to observation or forecast.

Ceiling

Height above the Earth's surface of the base of the lower cloud layer whose amount exceeds a specific value.

isVariable

An indicator which denotes a ceiling of less than 3,000 feet, which rapidly increases or decreases in height by established criteria during the period of observation.

lowerBoundVariableCeiling

The lowest variable ceiling height evaluated.

upperBoundVariableCeiling

The highest variable ceiling height evaluated.

HorizontalVisibility

An aggregation of horizontal visibility conditions typically reported together at an aerodrome, including the prevailing visibility and minimum visibility.

isPrevailingVisibilityAbove10000metres

Indication that the prevailing visibility is of at least 10000 meters.

isUnidirectionalVisibility

Indication whether the horizontalVisibility is given for a single direction or not.

minimumVisibility

Visibility for aeronautical purposes is the greater of:
a) the greatest distance at which a black object of suitable dimensions, situated near the ground, can be seen and recognized when observed against a bright background;
b) the greatest distance at which lights in the vicinity of 1 000 candelas can be seen and identified against an unlit background.

minimumVisibilityDirection

The direction of the minimum visibility relative to the reporting station.

prevailingVisibility

The greatest visibility value, observed in accordance with the definition of "visibility", which is reached within at least half the horizon circle or within at least half of the surface of the aerodrome. These areas could comprise contiguous or non-contiguous sectors.

RunwayVisualRange

The range over which the pilot of an aircraft on the centre line of a runway can see the runway surface markings or the lights delineating the runway or identifying its centre line.

rvrTendency

When instrumented systems are used for the assessment of runway visual range, the variations in runway visual range during the 10-minute period immediately preceding the observation.

rvrValue

Value of the Runway Visual Range.

rvrValueInterpretation

The relational operator that can be used for interpreting the RVR value, for instance in order to express a mean RVR of at least 2000 meters (ABOVE 2000 meters).

associatedRunwayDirection

RunwayDirection

The runway direction for which the RVR is specified.

Route

A specified route designed for channeling the flow of traffic as necessary for the provision of air traffic service (ATS) from the end of the take-off and initial climb phase to the commencement of the approach and landing phase.

designatorNumber

Integer

The number of the route designator.

designatorPrefix

CharacterString

CodeRouteDesignatorPrefixType

A prefix for the route designator, indicating whether the route is upper ATS, reserved for helicopters or reserved for supersonic flights.

designatorSecondLetter

CharacterString

CodeRouteDesignatorLetterType

The letter of the route designator, which may have special significance with regard to the route usage limitations, depending on the region.

Runway

A defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft.

Runway

designator

CharacterString

The designator of a runway, used to uniquely identify it at an aerodrome.

designator

type

CodeRunwayType

The type of runway.

type

associatedAerodrome

The aerodrome the runway is associated with.

associatedAirportHeliport

RunwayDirection

One of the two possible landing and/or take-off directions of a runway or Final Approach and Take-off Area (FATO).

RunwayDirection

designator

CharacterString

A designator for one of the two possible landing and/or take-off directions of a runway or final approach and take-off area.

designator

trueBearing

Angle

The measured angle between the runway direction and true north at a given position.

trueBearing

magneticBearing

Angle

The measured angle between the runway direction and magnetic north at a given position.

magneticBearing

usedRunway

Runway

The runway used by the runway direction.

usedRunway

WeatherInformationSource

WeatherInformationSource

An automated or non-automated weather information source.

Note: This is the root for the various weather information sources.

isAltimeterInformationProvided

WeatherInformationSource.isAltimeterInformationProvided

Indicates whether the weather source provides altimeter information.

isWeatherStation

WeatherInformationSource.isWeatherStation

Indicator that the source is a weather station.

AutomatedWeatherObservationSystem

Automated sensor suites which are designed to serve aviation and meteorological observing needs for safe and efficient aviation operations and weather forecasting.

weatherSystemName

The name of the weather observation system.

NonAutomatedWeatherObservationSource

nonAutomatedWeatherInformationSourceType

CodeNonAutomatedWeatherInformationSourceType

The type of weather information source.

ManualSurfaceWeatherObservation

Manual Surface Weather Observation

NonAutomatedWeatherObservationInstrument

Non-Automated Weather Observation Instrument

weatherInstrumentType

CodeWeatherInstrumentType

The type of weather instrument used in non-automated weather observation.

SurfaceWeatherObservation

Surface weather observations provide numerous weather elements, that are observed by a variety of sensors, both measurable (e.g., pressure and temperature) and derived elements (e.g., density altitude).   

surfaceWeatherObservationSystemType

CodeSurfaceWeatherObservationSystem

The type of surface weather observation system.

WeatherPhenomenon

WeatherPhenomenon

A meteorological event.

Note: This is the root for the various weather phenomena.

base

ValDistanceType

Altitude of the lowest level of the description of a weather phenomenon.

intensity

CodeWeatherIntensityType

Severity of a weather phenomenon.

phenomenonType

CodeWeatherPhenomenonType

Description of the type of a weather phenomenon.

Note: The codelist gives phenomena that have no additional properties of their own.

significantWeatherQualifier

CodeSignificantWeatherQualifierType

A qualifier used in association with a reported significant weather phenomenon.

top

ValDistanceType

Altitude of the highest level of the description of a weather phenomenon.

movement

MovementDescription

The movement of the weather phenomenon.

weatherCondition

WeatherCondition

The observation or forecast of the weather phenomenon.

MovementDescription

Movement information associated with a phenomenon.

applicability: En-route significant weather only.

directionFrom

The angle from which the meteorological phenomenon is moving.

directionTowards

Heading of the movement of a meteorological phenomenon.

fromCardinalDirection

The cardinal direction from which the meteorological phenomenon is moving.

isStationary

Indication whether a meteorological phenomenon is moving or not.

speed

Speed of the movement of the meteorological phenomenon.

towardsCardinalDirection

The cardinal direction towards which the meteorological phenomenon is moving.

Cloud

A hydrometeor consisting of minute particles of liquid water or ice, or of both, suspended in the free air and usually not touching the ground. It may also include larger particles of liquid water or ice and non-aqueous liquid or solid particles such as those present in fumes, smoke and dust.

AerodromeCloudForecast

cloudAmount

CodeCloudAmountType

Fraction of the sky covered by the clouds of a certain genus, species, variety, layer or combination of clouds.

cloudType

CodeCloudType

Categorization of the cloud depending on its main characteristics.

isAmoutAndBaseNotObservable

Boolean

Indication that cumulonimbus clouds or towering cumulus clouds are detected by the automatic observing system but the cloud amount and the height of cloud base cannot be observed.

isEmbedded

Boolean

Surrounded, or part of a wider cloud layer, in opposition to isolated.

isNoCloudDetected

Boolean

No clouds are detected by the automatic observing system.

isNoSignificantCloudDetected

Boolean

No clouds of operational significance are detected by the ceilometer(s) in reports from fully automatic observing systems.

isObscured

Boolean

Hidden or out of sight by haze, smoke or cloud for example.

isWidespread

Boolean

Affecting a large area.

Convection

In the atmosphere, convection is the dominant vertical transport process in convective boundary layers, which are common over tropical oceans and, during sunny days, over continents. Moist convection in the atmosphere is characterized by deep, saturated updrafts and downdrafts, and unsaturated downdrafts driven by the evaporation and melting of precipitation. This form of convection is made visible by cumulus clouds and cumulonimbus clouds in the case of precipitation convection.

ConvectionCell

A volume of convective air.

convectionCellOvershootPosition

TwoDimensionalPointType

Location in latitude and longitude of the convection cell overshoot.

convectionCellTopVariation

CodeConvectionCellTopVariationType

The observed variation of the altitude of the upper part convection cell.

convectionCellType

CodeConvectionCellType

Indication whether the convection cell described is the base (cell base) of a cell, or the upper part of a cell (cell top).

Icing

Formation of ice, rime, or hoarfrost on an aircraft in flight.

accretionRate

Decimal

Ratio of growth of the ice deposit.

Obscuration

A weather phenomenon which reduces the visibility due to hydrometeor or lithometeor in suspension in the air.

type

CodeObscurationType

Type of hydrometeor.

Precipitation

Hydrometeor consisting of a fall of an ensemble of particles. The forms of precipitation are: rain, drizzle, snow, snow grains, snow pellets, diamond dust, hail and ice pellets.

amount

Integer

Total amount of precipitation measured over a defined period, expressed in mm/hours.

type

CodePrecipitationType

Description of the precipitation characteristics using a classification.

TornadicVortex

A violently rotating column of air, usually pendant to a cumulonimbus, with circulation reaching the ground. It nearly always starts as a funnel cloud and may be accompanied by a loud roaring noise.

isFunnelCloud

Boolean

Indicates a violent, rotating column of air, which does not touch the surface, usually appended to a cumulonimbus cloud.

isTornado

Boolean

Indicates a violent, rotating column of air touching the ground. It forms a pendant, usually from a cumulonimbus cloud, nearly always starts as a funnel cloud, and is accompanied by a loud roaring noise.

isWaterspout

Boolean

Indicates a violent, rotating column of air that forms over a body of water, and touches the water surface; tornado or funnel cloud that touches a body of water.

TropicalCyclone

Cyclone of tropical origin of small diameter (some hundreds of kilometres) with minimum surface pressure in some cases less than 900 hPa, very violent winds and torrential rain; sometimes accompanied by thunderstorms. It usually contains a central region, known as the "eye" of the storm, with a diameter of the order of some tens of kilometres, and with light winds and more or less lightly clouded sky.

applicability: En-route significant weather only.

centralPressure

ValPressureType

Pressure at the centre of the cyclone.

maxSurfaceWindSpeed

ValSpeedType

Maximum surface wind speed of a tropical cyclone.

name

CharacterString

Name of the tropical cyclone.

Turbulence

Atmospheric flow regime characterized by chaotic and stochastic property changes. This includes low momentum diffusion, high momentum convection, and rapid variation of pressure and velocity in space and time.

applicability: En-route significant weather only.

edr

Decimal

Eddy dissipation rate, characterization of atmospheric turbulence.

turbulenceType

CodeTurbulenceType

The type of turbulence.

VolcanicActivity

Volcanic unrest or eruption.

isErupting

Indication wether a volcano is erupting or not.

ashCloud

VolcanicAshCloud

The volcanic ash cloud generated by the volcanic activity.

VolcanicAshCloud

Ash contaminated atmospheric volume.

ashConcentration

ValConcentrationType

Mass concentration of ash in an ash cloud expressed in mass unit per volume unit.

volcanicActivity

VolcanicActivity

The volcanic activity at the origin of the volcanic ash cloud.

WeatherLayer

An array of clouds and/or obscurations whose bases are at approximately the same level.   

obscuration

Obscuration

An obscuration forming part of the weather layer.

cloud

Cloud

A cloud forming part of the weather layer.

Wind

Air motion relative to the Earth's surface. Unless otherwise specified, only the horizontal component is considered.

crosswind

ValSpeedType

A wind blowing perpendicularly to one's direction of travel or orientation.

extremeClockwiseWindDirection

Angle

The extreme clockwise direction from which the wind is blowing, inclusive.

extremeCounterClockwiseWindDirection

Angle

The extreme counter-clockwise direction from which the wind is blowing, inclusive.

headwind

ValSpeedType

A wind blowing from directly in front, opposing forward motion or orientation.

isCalm

Boolean

Indication that the wind is forecast to be less than 0.5 m/s (1 kt).

isVariable

Boolean

Indication that the direction of the wind changes frequently. According to Annex 3 the wind is reported as variable (VRB) in local routine or special reports, in METAR and SPECI, when one of the following situations occur:
- when the total variation is 60 or more and less than 180 and the wind speed is less than 1.5 m/s (3 kt), the wind direction shall be reported as variable with no mean wind direction; or
- when the total variation is 180 or more, the wind direction shall be reported as variable with no mean wind direction.

maxWindSpeed

ValSpeedType

The maximum speed of the wind.

minWindSpeed

ValSpeedType

The minimum speed of the wind.

verticalWindGust

ValSpeedType

Component wind gust in the upward or downward direction.

windDirection

Angle

Direction from which wind is blowing.

windGust

ValSpeedType

Variation from the mean surface wind speed as defined by ICAO Annex 3.

windSpeed

ValSpeedType

The speed of the wind.

WindShear

Local variation of the wind vector or any of its components in a given direction.

level

ValDistanceType

Altitude expressed as a vertical distance where the wind shear occurs.

CodeAirspaceType

CodeAirspaceType

A coded list of values that indicates a type of airspace.

CodeAirspaceType

NAS

CodeAirspaceType.NAS

National Airspace System.

[note: The airspace within which a State provides Air Traffic Services is usually composed of:1) the territories over which the State has jurisdiction;2) those portions of the airspace over the high seas or in airspace of undetermined sovereignty where the provision of ATS are provided as determined by regional agreements. It can usually be determined by the UNION of FIRs (including, where appropriate, NO-FIRs) of the UNION of NAS-P. .]

CodeAirspaceType

FIR

CodeAirspaceType.FIR

Flight information region. Airspace of defined dimensions within which flight information service and alerting service are provided.

Description:

ICAO Recognized.

Might, for example, be used if service provided by more than one unit.

CodeAirspaceType

TMA

CodeAirspaceType.TMA

Terminal control area. Control area normally established at the confluence of ATS routes in the vicinity of one or more major aerodromes.

Description:

Non-ICAO Recognized.

Mainly used in Europe under the Flexible Use of Airspace concept.

CodeAirspaceType

OTHER

CodeAirspaceType.OTHER

Other

CodeChangeIndicatorType

CodeChangeIndicatorType

A code describing the type of meteorological conditions changes.

CodeChangeIndicatorType

BECMG

A code used to describe changes where the meteorological conditions are expected to reach or pass through specified threshold values at a regular or irregular rate and at an unspecified time during the time period.

CodeChangeIndicatorType

NOSIG

No significant changes are forecast with respect to the current meteorological conditions.

CodeChangeIndicatorType

TEMPO

A code used to describe expected frequent or infrequent temporary fluctuations in the meteorological conditions which reach or pass specified threshold values and last for a period of less than one hour in each instance and, in the aggregate, cover less than one-half of the forecast period during which the fluctuations are expected to occur.

CodeCloudAmountType

CodeCloudAmountType

Amount of cloud - assessed by category.

CodeCloudAmountType

BROKEN

(5 to 7 oktas)

CodeCloudAmountType

FEW

(1 to 2 oktas)

CodeCloudAmountType

OVERCAST

(8 oktas)

CodeCloudAmountType

SCATTERED

(3 to 4 oktas)

CodeCloudAmountType

SCATTERED_BROKEN

SCATTERED or BROKEN

CodeCloudAmountType

SKY_CLEAR

(0 oktas)

CodeCloudType

CodeCloudType

A code describing the types of cloud.

CodeCloudType

ALTOCUMULUS

White or grey, or both white and grey, patch, sheet or layer of cloud, generally with shading, composed of laminae, rounded masses, rolls, etc., which are sometimes partly fibrous or diffuse and which may or may not be merged most of the regularly arranged small elements usually have an apparent width of between one and five degrees.

CodeCloudType

ALTOSTRATUS

Greyish or bluish cloud sheet or layer of striated, fibrous or uniform appearance, totally or partly covering the sky, and having parts thin enough to reveal the Sun at least vaguely, as through ground glass. Altostratus does not show halo phenomena.

CodeCloudType

CIRROCUMULUS

Thin, white patch, sheet or layer of cloud without shading, composed of very small elements in the form of grains, ripples, etc., merged or separated, and more or less regularly arranged most of the elements have an apparent width of less than one degree.

CodeCloudType

CIRROSTRATUS

Transparent, whitish cloud veil of fibrous (hair-like) or smooth appearance, totally or partially covering the sky, and generally producing halo phenomena.

CodeCloudType

CIRRUS

Detached clouds in the form of white, delicate filaments or white or mostly white patches or narrow bands. These clouds have a fibrous (hair-like) appearance, or a silky sheen, or both.

CodeCloudType

CUMULONIMBUS

Dense and heavy cloud with a considerable mountain- or tower-shaped vertical extension. These clouds, the base of which is quite dark, may give rise to thunderstorms and generally heavy precipitation in the form of rain, snow, fine or large hail, sometimes accompanied by strong wind gusts.

CodeCloudType

CUMULUS

Detached cloud, generally dense and with sharp outlines, developing vertically in the form of rising mounds, domes or towers, of which the bulging upper part is often like a cauliflower. The sunlit parts are mostly brilliant white and the base is relatively dark and nearly horizontal. Sometimes Cumulus clouds are ragged.

CodeCloudType

NIMBOSTRATUS

Grey cloud layer, often dark, the appearance of which is rendered diffuse by more or less continuously falling rain or snow, which in most cases reaches the ground. It is thick enough throughout to blot out the Sun. Low, ragged clouds frequently occur below the layer, with which they may or may not merge.

CodeCloudType

STRATOCUMULUS

Banks or a layer of grey or whitish clouds generally caught on mountaintops. The base may be fuzzy or smooth and generally horizontal.

CodeCloudType

STRATUS

Generally grey cloud layer with a fairly uniform base, which may give drizzle, ice prisms or snow grains. When the Sun is visible through the cloud, its outline is clearly discernible Stratus does not produce halo phenomena except, possibly, at very low temperatures sometimes it appears in the form of ragged patches.

CodeCloudType

TOWERING_CUMULUS

 A descriptive term, used mostly in weather observing, for cumulus congestus (Cu con).

CodeConvectionCellTopVariationType

CodeConvectionCellTopVariationType

A code describing the dynamic behaviour of the top of a convection cell.

CodeConvectionCellTopVariationType

CONSTANT

Indicates no sensible variation of the top altitude of a convection cell.

CodeConvectionCellTopVariationType

DECAYING

Indicates that the top altitude of a convection cell is lowering.

CodeConvectionCellTopVariationType

GROWING

Indicates that the top altitude of a convection cell is increasing.

CodeConvectionCellType

CodeConvectionCellType

A code indicating whether a convection cell described is the base (cell base)  of a cell, or the upper part of a cell (cell top).

CodeConvectionCellType

CELL_BASE

The base (cell base) of a cell.

CodeConvectionCellType

CELL_TOP

The upper part of a cell (cell top).

CodeNonAutomatedWeatherInformationSourceType

CodeNonAutomatedWeatherInformationSourceType

The types of non-automated weather information source.

CodeNonAutomatedWeatherInformationSourceType

MANUAL_SURFACE_WEATHER_OBSERVATION

Manual Surface Weather Observation

CodeNonAutomatedWeatherInformationSourceType

WEATHER_INSTRUMENT

Weather Instrument.

CodeObscurationType

CodeObscurationType

A code describing the obscuration types.

ObscurationType

DUST

Earth or other solid matter in a minute and fine state of subdivision, so that the particles are small and light enough to be easily raised and carried in a cloud by the wind any substance comminuted or pulverized powder.

CodeObscurationType

FOG

A suspension of very small, usually microscopic water droplets in the air, reducing visibility at the Earth's surface.

CodeObscurationType

HAZE

Suspension in the atmosphere of extremely small, dry particles which are invisible to the naked eye but numerous enough to give the sky an opalescent appearance.

CodeObscurationType

MIST

Suspension in the air of microscopic water droplets or wet hygroscopic particles which reduce the visibility at the Earth's surface.

CodeObscurationType

SAND

A material consisting of comminuted fragments and water-worn particles of rocks (mainly silicious) finer than those of which gravel is composed.

CodeObscurationType

SMOKE

Suspension in the atmosphere of small particles produced by combustion.

CodeObscurationType

SPRAY

Ensemble of water droplets torn by the wind from the surface of an extensive body of water, generally from the wave crests, and carried up a short distance into the air.

CodeObscurationType

UNIDENTIFIED

That has not been identified of which the identity has not been established.

CodeObscurationType

VOLCANIC_ASH

Extremely fine particles of pulverized rock, the composition of which, generally speaking, is comprised predominantly of silica (> 50 per cent), together with smaller amounts of the oxides of aluminium, iron, calcium and sodium.

CodePrecipitationType

A code describing the precipitation types.

CodePrecipitationType

DRIZZLE

Fairly uniform precipitation in very fine drops of water (diameter less than 0.5 mm) very close to one another, falling from a cloud.

CodePrecipitationType

HAIL

Precipitation of either transparent, or partly or completely opaque particles of ice (hailstones), usually spheroidal, conical or irregular in form and of diameter very generally between 5 and 50 millimetres, which falls from a cloud either separately or agglomerated into irregular lumps.

CodePrecipitationType

ICE_CRYSTALS

Any one of a number of macroscopic crystalline forms of ice including hexagonal columns and platelets, dendritic crystals, ice needles and their combinations.

CodePrecipitationType

ICE_PELLETS

Precipitation of transparent particles of ice which are spherical or irregular, rarely conical, and which have a diameter of 5 mm or less.

CodePrecipitationType

RAIN

Precipitation of liquid water particles, either in the form of drops of more than 0.5 mm in diameter, or of smaller widely scattered drops.

CodePrecipitationType

SMALL_HAIL

Precipitation of translucent ice particles, which falls from a cloud. These particles are almost always spherical and sometimes have conical tips. Their diameter may attain or even exceed five millimetres.

CodePrecipitationType

SNOW

Precipitation of ice crystals, isolated or agglomerated, falling from a cloud.

CodePrecipitationType

SNOW_GRAINS

Precipitation of very small opaque white particles of ice which fall from a cloud and which are fairly flat or elongated with diameters generally less than 1 mm.

CodePrecipitationType

SNOW_PELLETS

Precipitation of white and opaque ice particles, which fall from a cloud and which are generally conical or rounded, with diameters attaining as much as 5 mm.

CodePrecipitationType

SUPERCOOLED_LARGE_DROPLET

Liquid droplets with diameters greater than 0.05 mm (50 microns) at temperatures less than 0°C, i.e., freezing rain or freezing drizzle. Due to their relatively large size and high mass, SLD are particularly hazardous to aircraft, since they can impact the aircraft surfaces outside the ice-protected regions.

CodePrecipitationType

UNIDENTIFIED

Unidentified precipitation.

CodePrecipitationType

UNKNOWN

Unknown precipitation.

CodeRVRTendencyType

CodeRVRTendencyType

A code indicating, when instrumented systems are used for the assessment of RVR, the tendency (upward or downward) of the variations in RVR during the 10-minute period immediately preceding the observation.

CodeRVRTendencyType

D

Downward RVR tendency

CodeRVRTendencyType

N

No RVR change tendency

CodeRVRTendencyType

U

Upward RVR tendency

CodeSignificantWeatherQualifierType

Qualifiers used in association with a reported significant weather phenomenon.

CodeSignificantWeatherQualifierType

BLOWING

Raised by the wind to a moderate height above the ground (2 meters or more).

CodeSignificantWeatherQualifierType

FREEZING

Precipitation freezing on impact on the ground and on exposed objects.

CodeSignificantWeatherQualifierType

LOW_DRIFTING

In motion due to the action of wind or raised by the wind to a small height above the ground (less than 2 meters).

CodeSignificantWeatherQualifierType

PARTIAL

Covering part of the aerodrome.

CodeSignificantWeatherQualifierType

PATCHES

Occurrences over small areas.

CodeSignificantWeatherQualifierType

PROXIMITY

The weather phenomenon is observed between approximately 8 km and 16 km from the aerodrome reference point.

CodeSignificantWeatherQualifierType

SHALLOW

Has a very little vertical extent.

CodeSignificantWeatherQualifierType

SHOWER

Precipitation, often short-lived and heavy, falling from convective clouds. A shower is characterized by its sudden beginning and ending, and generally by large and rapid changes of intensity.

CodeSignificantWeatherQualifierType

THUNDERSTORM

Sudden electrical discharges manifested by a flash of light (lightning) and a sharp or rumbling sound (thunder). Thunderstorms are associated with convective clouds (Cumulonimbus) and are, more often, accompanied by precipitation in the form of rainshowers or hail, or occasionally snow, snow pellets, or ice pellets.

CodeSurfaceWeatherObservationSystem

CodeSurfaceWeatherObservationSystem

The types of surface weather observation systems.

CodeSurfaceWeatherObservationSystem

AUTOMATED_SURFACE_OBSERVING_SYSTEM

Automated sensor suites that are designed to serve meteorological and aviation observing needs.

CodeSurfaceWeatherObservationSystem

AUTOMATED_WEATHER_OBSERVING_SYSTEM

Automated Weather Observing System (AWOS) is a fully configurable airport weather system that provides continuous, real time information and reports on airport weather conditions. AWOS stations are mostly operated, maintained and controlled by aviation service providers. 

CodeSurfaceWeatherObservationSystem

AUTOMATED_WEATHER_SENSOR_SYSTEM

An advanced AWOS system. It utilizes the complex National Weather Service ASOS algorithms for data processing and distribution.

CodeSurfaceWeatherObservationSystem

JUNEAU_AIRPORT_WIND_SYSTEM

AWS generates turbulence alerts every minute for hazardous areas in the vicinity of Juneau airport.

CodeSurfaceWeatherObservationSystem

LOW_LEVEL_WIND_SHEAR_ALERT_SYSTEM

A Low level wind shear alert system measures average surface wind speed and direction using a network of remote sensor stations, situated near runways and along approach or departure corridors at an airport. 

CodeSurfaceWeatherObservationSystem

RUNWAY_VISUAL_RANGE_SYSTEM

System for measuring runway visual range.

CodeSurfaceWeatherObservationSystem

STANDALONE_WEATHER_SENSOR

A standalone weather sensor.

CodeTurbulenceType

CodeTurbulenceType

A code describing the types of turbulence.

CodeTurbulenceType

CLEAR_AIR_TURBULENCE

Upper-atmospheric turbulence encountered by an aircraft when flying through clear air.

CodeTurbulenceType

IN_CLOUD_TURBULENCE

Upper-atmospheric turbulence encountered by an aircraft when flying through a cloud.

CodeValueContaminationExtentType

CodeValueContaminationExtentType

A code describing the proportion of a runway surface that is contaminated by a contaminant, as a percentage of the total runway area.

CodeValueContaminationExtentType

LESS_THAN_10_PERCENT

Less than 10%

CodeValueContaminationExtentType

BETWEEN_11_AND_25_PERCENT

Between 11% and 25%

CodeValueContaminationExtentType

BETWEEN_26_AND_50_PERCENT

Between 26% and 50%

CodeValueContaminationExtentType

MORE_THAN_50_PERCENT

More than 50%

CodeWeatherConditionType

CodeWeatherConditionType

The type of weather condition being reported.

CodeWeatherConditionType

METEOROLOGICAL_FORECAST

A statement of expected meteorological conditions for a specified time or period, and for a specified area or portion of airspace.

CodeWeatherConditionType

METEOROLOGICAL_OBSERVATION

The evaluation of one or more meteorological elements.

CodeWeatherInstrumentType

CodeWeatherInstrumentType

The type of non-automated instrumentation being used to measure weather data reported by a Weather Source.

CodeWeatherInstrumentType

ANEMOMETER

Measures wind speed, either directly, e.g. with rotating cups, or indirectly, e.g. via pressure differences or the propagation speed of ultrasound signals.

CodeWeatherInstrumentType

PITOT_TUBE

Pitot Tube.

CodeWeatherInstrumentType

RAWINSONDE

GPS-based wind measurement is performed by the probe.

CodeWeatherInstrumentType

WEATHER_BALLON

Passive measurement, balloon position is tracked from the ground visually or via radar wind profile is computed from drift rate and the theoretical speed of ascent.

CodeWeatherInstrumentType

WEATHER_VANE

Used to indicate wind direction.

CodeWeatherInstrumentType

WINDSOCK

Primarily used to indicate wind direction, may also be used to estimate wind speed by its angle.

CodeWeatherInstrumentType

WXCAM

Stationary camera that produces a visual image of the local weather.

CodeWeatherIntensityType

CodeWeatherIntensityType

A code indicating the weather intensity.

CodeWeatherIntensityType

LIGHT

A light intensity.

CodeWeatherIntensityType

LIGHT_MODERATE

A light to moderate intensity.

CodeWeatherIntensityType

MODERATE

A moderate intensity.

CodeWeatherIntensityType

MODERATE_SEVERE

A moderate to severe intensity.

CodeWeatherIntensityType

HEAVY

A heavy intensity.

CodeWeatherIntensityType

NONE

A report of no intensity (no icing present, for example) for a condition.  This is different from missing information.

CodeWeatherIntensityType

SEVERE

A severe intensity.

CodeWeatherIntensityType

UNKNOWN

A report of unknown intensity.

CodeWeatherPhenomenonType

A code describing the types of weather phenomenon.

CodeWeatherPhenomenonType

DUST_STORM

An ensemble of particles of dust energetically lifted to great heights by a strong and turbulent wind.

CodeWeatherPhenomenonType

DUST_WHIRL

An ensemble of particles of dust or sand, sometimes accompanied by small litter, raised from the ground in the form of a whirling column of varying height with a small diameter and an approximately vertical axis.

CodeWeatherPhenomenonType

FOG_BANK

Generally, a fairly well defined mass of fog observed in the distance, most commonly at sea. It is reported when occurring at the station. It is also reported when visible from the station but not occurring at the station and considered to be operationally significant.

CodeWeatherPhenomenonType

FUNNEL_CLOUD

Cloud formed at the core of a waterspout or tornado vortex, sometimes extending right down to the ground, caused by the reduction of pressure at the centre of the vortex.

CodeWeatherPhenomenonType

LIGHTNING

Luminous manifestation accompanying a sudden electrical discharge which takes place from or inside a cloud or, less often, from high structures on the ground or from mountains.

CodeWeatherPhenomenonType

MESOCYCLONE_ALOFT

A storm-scale region of rotation, typically around 2-6 miles in diameter and often found in the right rear flank of a supercell (or often on the eastern, or front, flank of a high precipitation storm).

The circulation of a mesocyclone covers an area much larger than the tornado that may develop within it. Properly used, mesocyclone is a radar term; it is defined as a rotation signature appearing on Doppler radar that meets specific criteria for magnitude, vertical depth, and duration.

CodeWeatherPhenomenonType

MOUNTAIN_OBSCURATION

Description of a visibility condition that is distinguished from IFR because ceilings, by definition, are described as "above ground level" (AGL). In mountainous terrain clouds can form at altitudes significantly higher than the weather reporting station and at the same time nearby mountain tops may be obscured by low visibility. In these areas the ground level can also vary greatly over a small area.

CodeWeatherPhenomenonType

MOUNTAIN_WAVE

Atmospheric internal gravity waves, which are periodic changes of atmospheric pressure, temperature and orthometric height in a current of air.

CodeWeatherPhenomenonType

OCEAN_ICE_OBSTRUCTION

Ocean ice obstruction is a large piece of freshwater ice that has broken off a glacier or an ice shelf and is floating freely in open water.

CodeWeatherPhenomenonType

RADIOACTIVE_CLOUD

A radioactive particulate contaminated atmospheric area.

CodeWeatherPhenomenonType

SAND_WHIRL

An ensemble of particles sand, sometimes accompanied by small litter, raised from the ground in the form of a whirling column of varying height with a small diameter and an approximately vertical axis.

CodeWeatherPhenomenonType

SANDSTORM

An ensemble of particles of sand energetically lifted to great heights by a strong and turbulent wind.

CodeWeatherPhenomenonType

SQUALL

Atmospheric phenomenon characterized by an abrupt and large increase of wind speed with a duration of the order of minutes which diminishes rather suddenly. It is often accompanied by showers or thunderstorms.

CodeWeatherPhenomenonType

TEMPERATURE_INVERSION

Vertical temperature distribution such that temperature increases with height.

CodeWindCharacteristicType

CodeWindCharacteristicType

When it is not possible to forecast a prevailing surface wind direction due to its expected variability, for example, during light wind conditions (less than 3 kt) or thunderstorms, the forecast wind direction should be indicated as variable using "VRB". When the wind is forecast to be less than 1 kt the forecast wind speed should be indicated as calm. When a wind speed of 20oKm/h (100kt) or more is forecast, it should be indicated as 200Km/h (or 100kt) [ICAO ANNEX 3, recommendation 6.2.12]

CodeWindCharacteristicType

100_KNOTS

Forecasted wind on airport surface is more than 100kt (200 Km/h)

CodeWindCharacteristicType

CALM

Wind direction on airport surface is irrelevant, wind is less than 1kt

CodeWindCharacteristicType

NORMAL

Wind on airport surface is normally described through the direction attribute

CodeWindCharacteristicType

VRB

Wind direction on airport surface is variable