Display of Meteorological Information

Display of Meteorological Information, AMC-DWD-01 (November 2017)

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Display of Meteorological Information

Acceptable Means of Compliance for Display of Digital Meteorological

Information ‒ AMC-DWD-01

Published by / Herausgeber: Deutscher Wetterdienst – Abteilung Flugmeteorologie Bundesoberbehörde des Bundesministeriums für Verkehr und digitale Infrastruktur Frankfurter Straße 135 63067 Offenbach Contact / Ansprechpartner: Referat WV22 Kundenservice Flugwetterdienst Telefon: + 49 (0)69 8062 2695 Fax: + 49 (0)69 8062 11925 E-Mail: [email protected]

Publication Date / Veröffentlicht am: 30. November 2017

Deutscher Wetterdienst – Abteilung Flugmeteorologie

(WV2/51.01.04/AMC-DWD-01/2017)

mailto:[email protected]


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Summary of Amendments and Changes

No. Date Change Entered by

000 14. 11. 2017 Version 1.0 Dr. Thomas Wetter

Erstellt: Geprüft: Freigabe nach Mitzeichnung:

Dr. Thomas Wetter, WV22 Dr. Christoph Leifeld, WV22 Klaus Sturm, WV2

Letzte Änderung: 14.11.2017 Datum: 23.11.2017 Datum: 27.11.2017


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Table of Contents

Foreword ............................................................................................................................... 4

Purpose and Scope ............................................................................................................... 4

Applicability ........................................................................................................................... 5

Reference Documents and Guidance Material ...................................................................... 5

EU Regulations and National Laws .................................................................................... 5

ICAO Regulations: Annexes and Manuals ......................................................................... 5

WMO Guidance Material .................................................................................................... 5

FAA Guidance Material ...................................................................................................... 5

Glossary of Definitions and Terms in the Context of this AMC ............................................... 6

Categorisation of Meteorological Information ........................................................................11

Observations (OBS) and Reports ......................................................................................11

Analysis (ANA) and Composites .......................................................................................11

Nowcasting Information ....................................................................................................11

Forecasts ..........................................................................................................................11

Advisories, Alerts and Warnings .......................................................................................11

Categorisation of Meteorological Products ...........................................................................12

Data Structures of Meteorological Products ......................................................................12

Common Data Formats of Meteorological Products ..........................................................12

Geo References ................................................................................................................12

Time References ..............................................................................................................12

Sources of Meteorological Data ............................................................................................13

Regulation of Aviation Meteorological Information and Products ..........................................13

Standard Products and Information ...................................................................................13

Recommended Meteorological Elements and Phenomena ...............................................14

Processing of Digital Meteorological Information and Products .........................................15

AMC-DWD-01/MET ..............................................................................................................16

Sources and Processing of Digital Meteorological Data (MET.DAT) .................................16

Display of Digital Meteorological Data (MET.VIS) .............................................................16

Personnel and Training (MET.PERS) ...............................................................................20

Documentation and Manuals (MET.DOC) .........................................................................21


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Foreword The objectives of meteorological services for international air navigation are to contribute towards the safety, regularity and efficiency of international air navigation. This objective shall be achieved by supplying the following users: operators, flight crew members, air traffic services units, air emergency and search-and-rescue servicess, airport managements and others concerned with the conduct or development of international air navigation, with the meteorological information necessary for the performance of their respective functions. For the last decades weather information in civil aviation was in accord with ICAO Annex 3 mainly presented to the aeronautical users either as printed black & white graphical charts (e.g. significant weather charts); or as plain text bulletins (e.g. METAR) conveyed printed, transmitted by voice or digital broadcasts. Textual meteorological products have been available through aircraft communications and reporting service (ACARS) for many years. More complex weather information, like gridded WAFC forecasts, were mainly used only for further processing in flight planning systems and were rarely graphically visualised. During the last years newer developments in internet based weather services and especially the innovations driven by the broad usage of mobile devices and GPS navigation systems in general aviation were pioneering the introduction of primarily graphical and interactive accessible weather information for aeronautical users. Additionally more meteorological products (e.g. satellite observations and ground based weather radar images) were established for the use of non-meteorological personnel for aviation purposes. With the introduction of Electronic Flight Bags (EFBs) into civil aviation, the rapid developments in this sector outpace the standards, regulations and laws for international civil aviation, thus hindering introduction of innovations due to lack of applicable rules and regulations. Furthermore, several fatal accidents in general aviation were direct linked to poorly implemented and/or wrongly used digital inflight weather information; thus calling for the provision of necessary standards addressing correct implementation and user training for the use of digital weather information to comply with the demands for safety in aviation. Therefore this publication comprises a coherent collection of standards and recommended practices to provide acceptable means of compliance for the display of digital meteorological information to facilitate the use of enhanced weather information to flight crew members, operators, air traffic services units, search and rescue services, and at aerodromes.

Purpose and Scope This Acceptable Means of Compliance (AMC) together with the corresponding guidance materials is one, but not the only, means to

(a) ensure the correct implementation and visualisation of digital weather information for aviation purposes to contribute towards safety, regularity and efficiency;

(b) enable the usage of aeronautical weather information within and beyond the standard forecasts, observations, advisories and warnings defined by ICAO;

(c) satisfactorily assess the operational and safety aspects and limitations for the use of digital weather information;

(d) provide the necessary basic principles for user training; (e) obtain approval and/or certification from the respective responsible agencies for

software developments and/or operational usage of digital weather information for aircraft operations, aerodrome operations, air traffic services and air navigation services.


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Applicability This AMC is intended to be used by:

(a) Commercial Air Transport (CAT) operators by aeroplane or by helicopter; (b) Air Traffic Service Units including Network Managers and Flight Information Services; (c) other Air Navigation Service Provider (ANSPs) using weather information; (d) Search-And-Rescue Services (SAR) and other air emergency units; (e) Airport management and stakeholders in Collaborative Decision Making (CDM) at

aerodromes; (f) Software developers with intended usage of digital weather information for

aeronautical applications.

Reference Documents and Guidance Material

EU Regulations and National Laws

COMMISSION IMPLEMENTING REGULATION (EU) 2017/373

COMMISSION REGULATION (EU) No 379/2014

Luftverkehrsgesetz (LuftVG)

ICAO Regulations: Annexes and Manuals

ICAO Annex 3 – Meteorological Service for International Air Navigation

ICAO Annex 11 – Air Traffic Services

ICAO Annex 15 – Aeronautical Information Services

ICAO Doc 4444 – Procedures for Air Navigation Services – Air Traffic Management

ICAO Doc 7488 – Manual of the ICAO Standard Atmosphere

ICAO Doc 7910 – Location Indicators

ICAO Doc 8169 – Procedures for Air Navigation Services – Aircraft Operations

ICAO Doc 8400 – Procedures for Air Navigation Services – Abbreviations and Codes

ICAO Doc 8896 – Manual of Aeronautical Meteorological Practice

ICAO Doc 9377 – Manual on Coordination between Air Traffic Services, Aeronautical Information Services and Aeronautical Meteorological Services

ICAO Doc 10003 – Manual on the Digital Exchange of Aeronautical Meteorological Information

ICAO Doc 10020 – Manual on Electronic Flight Bags (EFBs)

WMO Guidance Material

WMO-No. 8 – Guide to Meteorological Instruments and Methods of Observation

WMO-No. 306 Vol. I.1 – Manual on Codes: Part A – Alphanumeric Codes

WMO-No. 306 Vol. I.2 – Manual on Codes: Part B – Binary Codes and Part C – Common Features to Binary and Alphanumeric Codes

WMO-No. 731 – Guide on Meteorological Observing and Information Distribution Systems for Aviation Weather Services

WMO-No. 732 – Guide to Practices for Meteorological Offices serving Aviation

FAA Guidance Material

FAA AC 00-6b – Aviation Weather

FAA AC 00-45G – Aviation Weather Services

FAA AC 00-63A – Use of Cockpit Displays of Digital Weather and Aeronautical Information

FAA AC 120-76c Guidelines for the Certification, Airworthiness, and Operational Approval of Electronic Flight Bag Computing Devices


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Glossary of Definitions and Terms in the Context of this AMC 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.

Aeronautical fixed telecommunication network (AFTN). A worldwide system of

aeronautical fixed circuits provided, as part of the aeronautical fixed service, for the

exchange of messages and/or digital data between aeronautical fixed stations having the

same or compatible communications characteristics.

AGL. Above Ground Level

Aircraft. Any machine that can derive support in the atmosphere from the reactions of the air

other than the reactions of the air against the earth’s surface.

Aircraft Communications Addressing and Reporting System (ACARS). A data link

system using two-way Very High Frequency (VHF) data link air/ground communications for

Airline Operational Control (AOC), Airline Administrative Control (AAC), and ATC messages.

FIS request/reply and contract messages can be sent over the ACARS network.

Aircraft observation. The evaluation of one or more meteorological elements made from an

aircraft in flight.

Air-ground communication. Two-way communication between aircraft and stations or

locations on the surface of the earth.

Airside. The movement area of an airport, adjacent terrain and buildings or portions thereof,

access to which is controlled.

Air traffic control service. A service provided for the purpose of: a) preventing collisions:

1) between aircraft, and 2) on the manoeuvring area between aircraft and obstructions; and

b) expediting and maintaining an orderly flow of air traffic.

Air traffic control unit. A generic term meaning variously, area control centre, approach

control unit or aerodrome control tower.

Air traffic management (ATM). The dynamic, integrated management of air traffic and

airspace including air traffic services, airspace management and air traffic flow management

— safely, economically and efficiently — through the provision of facilities and seamless

services in collaboration with all parties and involving airborne and ground-based functions.

Air traffic management system. A system that provides ATM through the collaborative

integration of humans, information, technology, facilities and services, supported by air and

ground- and/or space-based communications, navigation and surveillance.

Altitude. The vertical distance of a level, a point or an object considered as a point,

measured from mean sea level (MSL). In aviation altitude is predominantly altimetric rather

than geometric, i.e. the altitude is determined based on the measurement of atmospheric

pressure.


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AMSL. Above Mean Sea Level

Automatic terminal information service (ATIS). The automatic provision of current, routine

information to arriving and departing aircraft throughout 24 hours or a specified portion

thereof:

(1) Data link-automatic terminal information service (D-ATIS). The provision of ATIS via

data link.

(2) Voice-automatic terminal information service (Voice-ATIS). The provision of ATIS by

means of continuous and repetitive voice broadcasts.

Broadcast. A transmission of information relating to air navigation that is not addressed to a

specific station or stations.

Commercial Air Transport (CAT) operation. An aircraft operation involving the transport of

passengers, cargo or mail for remuneration or hire.

Control area (CTA). A controlled airspace extending upwards from a specified limit above

the earth.

Data Link. A wireless telecommunication between two or more locations for the purpose of

transmitting or receiving data.

Data processing. A systematic sequence of operations performed on data. Examples of

operations are the merging, sorting, computing or any other transformation or rearrangement

with the object of extracting or revising information, or of altering the representation of

information.

Electronic Flight Bag (EFB). An information system for flight crew members which allows

storing, updating, delivering, displaying, and/or computing digital data to support flight

operations or duties.

En route. The en route domain consists of the airspace that surrounds the TMA domain

starting at ~FL245 to ~FL600. It is the continental (or domestic) airspace used by ATC for the

cruise portion of the flight. Oceanic, remote, and polar are operating domains similar to the

en route domain, except that they are associated with geographical areas generally outside

of continental airspace.

Flight crew member. A licensed crew member charged with duties essential to the

operation of an aircraft during a flight duty period.

Flight information region (FIR). An airspace of defined dimensions within which flight

information service and alerting service are provided.

Flight level (FL). A surface of constant atmospheric pressure which is related to a specific

pressure datum, 1013.25 hectopascals (hPa), and is separated from other such surfaces by

specific pressure intervals. Flight level altitude is defined in 100 feet units above sea-level

measured according to a standard atmosphere; e.g. FL250 = 25,000 feet above mean sea

level when the pressure at sea level is 1013.25 hPa.

Note 1.— A pressure type altimeter calibrated in accordance with the Standard Atmosphere: a) when set to a QNH altimeter setting, will indicate altitude; b) when set to a QFE meter setting, will indicate height above the QFE reference datum; c) when set to a pressure of 1013.25 hPa, may be used to indicate flight levels.


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Note 2.— The terms “height” and “altitude”, used in Note 1, indicate altimetric rather than geometric heights and altitudes.

Flight visibility. The visibility forward from the cockpit of an aircraft in flight.

Forecast. A statement of expected meteorological conditions for a specified time or period,

and for a specified area or portion of airspace.

General Aviation. Any civil aircraft operation other than aerial work or commercial air

transport.

Graphical Product. A meteorological product composed of graphics with associated

supporting text.

Ground visibility. The visibility at an aerodrome, as reported by an accredited observer or

by automatic systems.

Heading. The direction in which the longitudinal axis of an aircraft is pointed, usually

expressed in degrees from North (true, magnetic, compass or grid).

Height. The vertical distance of a level, a point or an object considered as a point, measured

from a specified datum. In aviation height is predominantly altimetric rather than geometric,

i.e. the height is determined based on the measurement of atmospheric pressure.

Human Factors principles. Principles which apply to aeronautical design, certification,

training, operations and maintenance and which seek safe interface between the human and

other system components by proper consideration to human performance.

Human performance. Human capabilities and limitations which have an impact on the

safety and efficiency of aeronautical operations.

ICAO. The International Civil Aviation Organization.

IFR. The acronym used to designate the Instrument Flight Rules.

IFR flight. A flight conducted in accordance with the Instrument Flight Rules.

In-Flight. Occurring, carried out, or present during flight.

In-Flight Weather. Information delivered to the cockpit to assist flight crew members in the

safe conduct of flight and aircraft movement. However, that delivery method may subject the

information to alteration, corruption, latency, or other impairments, as well as disruptions in

data link service. Users may not solely rely upon this information for making operational

decisions.

In-Flight Weather Application. An EFB function or application enabling the crew to access

meteorological information.

Information. Data that (1) has been verified to be accurate and timely, (2) is specific and

organized for a purpose, (3) is presented within a context that gives it meaning and

relevance, and which (4) leads to an increase in understanding and decrease in uncertainty.

The value of information lies solely in its ability to affect a behaviour, decision, or outcome.

Location indicator. A four-letter code group formulated in accordance with rules prescribed

by ICAO and assigned to the location of an aeronautical fixed station.


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Meteorological Data. A representation of meteorological observations or numerical weather

forecast model output in a formalized manner suitable for communication, interpretation or

processing.

Meteorological Element. A single parameter describing a measured variable in the

atmosphere (e.g. temperature, wind, pressure). In aviation this may also apply to non-

meteorological parameters moving within the atmosphere, like volcanic ash (VA), toxic

chemicals, or radioactive clouds (RDOACT CLD).

Meteorological Information. Information resulting from the assembly, analysis, and

formatting of meteorological data.

Meteorological Phenomenon. A weather event that can be explained by the principles of

meteorology (e.g. clouds, dust storm, precipitation). Some meteorological phenomena may

imply more than one meteorological element or additional phenomena; e.g. a thunderstorm

implies hail, icing, turbulence, and lightning.

Meteorological Product. A set or data set series of meteorological information produced

and displayed in accordance with a published or defined format in a manner usable and

interpretable to the designated user.

Meteorological Watch Office (MWO). An office monitoring meteorological conditions

affecting flight operations and providing information concerning the occurrence or expected

occurrence of specified en route weather phenomena, natural and other hazards which may

affect the safety of aircraft operations within a specified area of responsibility.

Near-Real-Time. Current or immediate information; responding to events or inputs as fast as

possible, or as they happen.

NOTAM (Notice(s) to Airmen). A notice distributed by means of telecommunication

containing information concerning the establishment, condition or change in any aeronautical

facility, service, procedure or hazard, the timely knowledge of which is essential to personnel

concerned with flight operations.

Preflight. This operational phase includes flight planning, briefing requirements, and aircraft

preparation. Operations responsibility for preflight planning is a shared function between the

pilot in command (PIC) and an aircraft dispatcher (domestic and flag operations) or between

the PIC and person authorized to exercise operational control (supplemental operations).

The flight crew will often not be on board the aircraft during the preflight planning phase.

However, preflight planning can continue all the way up until the point a flight takes off and is

en route.

Product Latency. An element of data age. The total latency of meteorological product

includes the total time between the actual occurrence of the phenomenon, the data

collection, processing, transmittal, and the display or application of the information. The

amount of total latency may limit the use or application of the information.

Runway visual range (RVR). 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.


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Strategic. This term refers to the decision-making process by the pilot. Strategic decision-

making addresses decisions related to flight planning, both pre-flight and in-flight.

Surface. The surface domain consists of an area approximately 16 km in diameter and up to

~5,000 feet above ground level (AGL), consisting of the airport/aerodrome surface and the

immediate vicinity of the airport/aerodrome. This domain is used by ATC for pre-departure,

taxi, take-off, and landing portions of the flight. Surface applies to both towered and non-

towered airports without an ATC presence. During this surface domain, it is assumed that the

aircraft has moved for the purpose of flight.

Tactical. This term refers to the decision-making process by the pilot. Tactical decision-

making involves decisions of an operational nature that need to be applied immediately.

Terminal Maneuvering Area (TMA). The TMA domain consists of the airspace surrounding

an airport/aerodrome, typically starting at ~5,000 feet AGL up to ~flight level (FL) 245. This is

the transition airspace used by ATC to merge and space aircraft for landing or for entrance

into the en route domain. The TMA typically radiates out ~50 nautical miles (NM) from the

center of an airport/aerodrome.

Text Product. An meteorological product that is composed of text only.

Transition altitude. The altitude at or below which the vertical position of an aircraft is

controlled by reference to altitudes.

Transition layer. The airspace between the transition altitude and the transition level.

Transition level. The lowest flight level available for use above the transition altitude.

Tropical cyclone advisory centre (TCAC). A meteorological centre designated by regional

air navigation agreement to provide advisory information to meteorological watch offices,

world area forecast centres and international OPMET databanks regarding the position,

forecast direction and speed of movement, central pressure and maximum surface wind of

tropical cyclones.

VFR. The acronym used to designate the Visual Flight Rules.

VFR flight. A flight conducted in accordance with the Visual Flight Rules.

Volcanic ash advisory centre (VAAC). A meteorological centre designated by regional air

navigation agreement to provide advisory information to meteorological watch offices, area

control centres, flight information centres, world area forecast centres and international

OPMET databanks regarding the lateral and vertical extent and forecast movement of

volcanic ash in the atmosphere following volcanic eruptions.

World area forecast centre (WAFC). A meteorological centre designated to prepare and

issue significant weather forecasts and upper-air forecasts in digital form on a global basis

direct to States using the aeronautical fixed service Internet-based services.

World area forecast system (WAFS). A worldwide system by which world area forecast

centres provide aeronautical meteorological en-route forecasts in uniform standardized

formats.

WMO. The World Meteorological Organization.


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Categorisation of Meteorological Information The following distinct types of weather information may be utilized to conduct aircraft operations, air navigation services and aerodrome operations: observations, analyses and composites, nowcasting information, forecasts, advisories, alerts and warnings.

Observations (OBS) and Reports

Observations are basic weather data collected by some type of sensor(s) and supplementary visual observations. The observations can either be in situ (e.g. surface or airborne) or remote (e.g. weather radar or satellite). Meteorological reports generally combine several observations sharing a common time reference for a location or area (e.g. MET REPORT, METAR or SPECI)

Analysis (ANA) and Composites

Analyses of weather information are an enhanced depiction and/or interpretation of observed weather data, generally combining a set of observations. Composites generally combine areal remote observations sharing a common time reference (e.g. a composite of weather radar data or satellite imagery).

Nowcasting Information

Nowcasting is weather forecasting on a very short time period of up to 2 hours. This forecast is generally an extrapolation in time of observed weather parameters using techniques that take into account a possible movement and/or evolution of the air mass. This type of weather forecast therefore includes details that cannot be covered by numerical weather prediction (NWP) models running over longer forecast periods. Nowcasting information is generally less accurate than observations, but far more accurate than normal weather forecasting. For aeronautical purposes it can be used to extrapolate observed significant weather and to remedy product latency times. Especially if nowcasting products are used to bridge latencies of less than 15 minutes, near-real-time applications with only a minimal cutback on quality compared to observations may be achieved.

Forecasts

Meteorological forecasts are the predictions of the development and/or movement of weather phenomena based on meteorological observations and forecast methods employing various physical models. Owing to the variability of meteorological elements in space and time and to limitations of weather forecasting methods, the specific value of any of the elements given in a forecast shall be understood by the recipient to be the most probable value which the element is likely to assume during the period of the forecast. Similarly, when the time of occurrence or change of an element is given in a forecast, this time shall be understood to be the most probable time. It is in the nature of forecasts that the quality of forecast decreases with increasing forecast time.

Advisories, Alerts and Warnings

These aviation products employ generally both current observations and forecasts of hazards in the atmosphere (e.g. advisory for volcanic ash or tropical cyclones, SIGMET/AIRMET for severe significant weather, low level wind shear and aerodrome warnings) and are issued by designated advisory centers or meteorological watch offices only. Advisories, alerts and warnings are generally based on the latest available observed and/or forecasted meteorological information and thus will be only issued, corrected, amended or canceled, whenever significant changes occur.


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Categorisation of Meteorological Products

Data Structures of Meteorological Products

The structure and coverage of digital meteorological products vary depending on data type and structure as listed below:

(a) 1D — data for a single point in time; (b) 2D — data over an area for a single point in time; (c) 2D — data covering cross-sections along/across flight routes or vertical profiles; (d) 2D — data representing a time series of data at a single location; (e) 3D — grid data over multiple levels; (f) 4D — evolution of a 3D grid over time; and (g) Object-oriented meteorological data.

Common Data Formats of Meteorological Products

Meteorological products are predominantly supplied in the following data formats: (a) Plain Text products in ASCII (b) Structured Text in XML/GML, IWXXM and BUFR (c) Graphical products and charts in PDF, PNG, GIF, TIFF and T4 (d) Binary data in GRIB2, HDF5, BUFR and NETCDF (e) Object-oriented data in BUFR, IWXXM and XML/GML

Geo References

Meteorological information needs always to be specified for time and location. The following geo references are common in aeronautical meteorological data:

(a) ICAO location indicator of an aeronautical fixed station (e.g. for aerodromes, ATS units);

(b) airspaces of defined dimensions (e.g. FIR, UIR, CTA); (c) coordinates defined by latitude and longitude, usually referring to standard coordinate

system, in particular WGS84;

(d) the vertical references of meteorological data are predominantly determined based on

atmospheric pressure in accordance with the ICAO Standard Atmosphere and refer

either to altimetric altitude, height or flight level.

Time References

Meteorological information needs always to be specified for time and location. The following time references are common in aeronautical meteorological data:

(a) The Coordinated Universal Time (UTC) is the primary time standard; (b) observation time is the final time after the observation(s) are completed; (c) product time is the time a meteorological product is completed; (d) the fixed time of a forecast defines a single moment; (e) the validity time of a product may refer either to a fixed time or a period of time were

the observation, forecast or warning is assumed valid; (f) the age of a product refers to the time difference between the product/observation

time and the valid time; (g) for numerical weather forecast it is convenient to indicate

(1) the time of the model run, i.e. the time up to when the last used available observations are used;

(2) the fixed time of the forecast step (validity time); (3) the time difference between forecast step and model run, indicating the age of

the individual fixed time forecast.

Example: “Validity time 12 UTC 31 May, model run 06 UTC 30 May + 30h”


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Sources of Meteorological Data Appropriate originating sources for aeronautical meteorological data and/or products include:

National aeronautical meteorological services, MWOs, WAFCs, VAACs and TCACs. Other

sources should be certified air navigation service provider for meteorological services

operating according to WMO and ICAO regulations as approved by the responsible

meteorological authority.

Regulation of Aviation Meteorological Information and Products

Standard Products and Information

All aviation weather data products and meteorological information included in ICAO Annex 3 and the Commission Implementing Regulation (EU) 2017/373 are the mandatory meteorological provision to operators, flight crew members, air traffic services units, search and rescue services units, aerodrome operators, accident and incident investigation bodies, and other service providers and aviation entities. The following standard meteorological products with their data structure and data format, their distribution and applications are fully defined within the ICAO Standards and Recommended Practices and associated ICAO Manuals:

(a) METAR or SPECI, including TREND forecast; (b) local routine and special report; (c) TAF (Terminal Aerodrome Forecast); (d) SIGMET and AIRMET information; (e) WAFS forecasts; (f) Significant Weather Charts and wind and temperature charts; (g) PIREP(pilot weather report); (h) volcanic ash advisory information; (i) tropical cyclone advisory information; (j) wind shear warnings.

Additionally, the following meteorological information, their distribution and applications are defined within the ICAO Standards and Recommended Practices and associated ICAO Manuals, but without a definite technical specification of a meteorological product, the data structure or data format:

(a) aerodrome forecasts and/or warnings for local meteorological conditions; (b) aerodrome forecasts for take-off; (c) area forecasts for low-level flights; (d) meteorological satellite images; (e) ground-based weather radar information; (f) lightning location display; (g) vertical wind profiles; (h) short term forecasts (nowcasting information); (i) vertical wind profiles; (j) terminal movement area (TMA) weather products for “tailored approaches”.


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Recommended Meteorological Elements and Phenomena

Apart from standard meteorological products and information the following digital data of meteorological elements and/or phenomena may be additionally considered for display to users of meteorological information in aviation, tailored to their respective operational needs, to facilitate an increased situational awareness and to support decision-making processes: Observations or forecasts of basic meteorological elements

(a) wind (surface wind and gusts, upper winds, position and speed of jet stream); (b) temperature (surface temperature, frost, upper air temperature); (c) humidity (dew-point temperature and upper air humidity); (d) surface air pressure (QNH, QFE, QFF), pressure altitude (QNE) and density altitude; (e) geopotential altitude of flight levels.

Observations or forecasts of meteorological and atmospheric phenomena

(f) cloud amount and height indications of bases and tops; (g) convective events and height indications of bases and tops (cumulonimbus cloud,

thunderstorm, towering cumulus); (h) extreme wind events (funnel cloud, squall line, wind-shear, downburst); (i) turbulence (clear-air-turbulence, mountain wave); (j) flight level and temperature of tropopause; (k) precipitation and freezing precipitation (drizzle, rain, snow, snow grains, ice pellets,

small hail/snow pellets, hail); (l) aircraft icing conditions, ice crystal icing; (m) visibility, ceiling and mountain obscuration (in the context of clouds); (n) visibility and obscuration by hydrometeors (fog, mist); (o) visibility and obscuration lithometeors (sand, dust, haze, smoke, volcanic ash); (p) prevailing visibility and measurements of runway visual range (RVR); (q) duststorms and sandstorms, low drifting/blowing dust, sand or snow; (r) tropical cyclone; (s) volcanic ash; (t) radioactive clouds; (u) toxic chemicals;

Additional information used in conjunction with meteorological data

(v) state of ground, in particular, any snow cover or flooding; (w) sea-surface temperature, state of the sea, ice cover if any and ocean currents; (x) space weather information; (y) astronomical data (sunset, twilight, sunrise, moonrise, moonset).


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Processing of Digital Meteorological Information and Products

The process to convey digital aeronautical meteorological information and products include five basic functions as described below:

(a) Step 1: Data Assembling Assembling of basic meteorological data from observations or numerical weather forecast model output;

(b) Step 2: Product Generation and Supply Processing and formatting of the meteorological information into aeronautical meteorological products in a formalized manner suitable for communication, interpretation or further processing and provision of the products;

(c) Step 3: Product Selection Selection of the required aeronautical meteorological products and conducting further processing, segmenting or reformatting as necessary for transmission;

(d) Step 4: Product Transmission Transmitting and receiving the digitally coded products; and

(e) Step 5: Product Display and Application Decoding (if necessary), filtering (if appropriate) and displaying the data on displays for recipient user review or to further process data for other user applications.

The functions addressed in steps 1 and 2 are dedicated tasks for the respectively responsible certified air navigation service provider for meteorological services and subject to quality control according to national and international standards as required by national law and regulations of the European Commission, ICAO and WMO. The functions from step 3 to step 5 are to be carried out by the recipient user of the digital aeronautical meteorological products. This AMC shall enable the recipient users to obtain approval and/or certification from the respective responsible agencies which exercise certification, oversight and enforcement tasks for aircraft operations, aerodrome operations, air traffic services and air navigation services, where the operational usage of the digital weather information is implemented.


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AMC-DWD-01/MET Acceptable Means of Compliance for Display of Digital Meteorological Information

Sources and Processing of Digital Meteorological Data (MET.DAT)

AMC-DWD-01/MET.DAT.001 Scope The subpart MET.DAT establishes the requirements to be met to use digital meteorological data for operational aviation purposes. AMC-DWD-01/MET.DAT.010 Sources (a) Only appropriate originating sources for meteorological data and/or products shall be

used for operational aviation purposes; (b) For every meteorological data and product used, the originating source and, if applicable,

the supplying service provider shall be (1) documented in the technical and operational manuals; (2) visual accessible to the recipient (e.g. printed in a legend); (3) included in appropriate metadata of datasets, if applicable.

AMC-DWD-01/MET.DAT.020 Range of meteorological data and information The meteorological data and information provided to the recipient user should be as far as possible consistent with the information available to other aviation meteorological information users in order to establish common situational awareness and to facilitate collaborative decision-making. AMC-DWD-01/MET.DAT.030 Data processing Any processing performed on meteorological data and products needed for display should be restrained to the following operations:

(a) extracting only required data or products to minimise data volume; (b) segmenting, merging or reformatting products as necessary for transmission; (c) filtering or prioritisation of products prior to display.

Any revising operation of computing or transformation applied on meteorological data shall not alter the information contained and preserve both the geo-location and intensity of the meteorological conditions regardless of projection, scaling, or any other types of processing. This excludes insignificant inaccuracies due to numerical processing.

Display of Digital Meteorological Data (MET.VIS)

AMC-DWD-01/MET.VIS.001 Scope The subpart MET.VIS establishes the requirements to be met to visualise digital meteorological data for operational aviation purposes. AMC-DWD-01/MET.VIS.002 Concurrent Regulations Whenever meteorological information is to be implemented for display in commercial air transport, air traffic services, aerodrome operations, general aviation, search and rescue operations, or any other air navigation service there are usually concurrent regulations in force for display requirements, software functionalities and the subsequent usage of information and products in these respective environments. If such regulations limit or exclude any acceptable means of compliance specified in this AMC, they must be considered prior to this AMC. If such regulations add further requirements, this AMC does not exempt these additional requirements.


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AMC-DWD-01/MET.VIS.005 General Remarks The display of meteorological products shall enable the recipient to easily access meteorological information to increase situational awareness and to support decisions. The information should be in a format that is appropriate to the content of the information; graphical depiction is encouraged whenever practicable. To ensure easy recognition, correct understanding and appropriate application of meteorological information the following essential key elements (MET.VIS.010 - 015) shall be included in any visualisation. Any display information beyond these key elements shall not interfere with the readability or comprehension of these elements. AMC-DWD-01/MET.VIS.010 Product Content Each meteorological information or product displayed shall include an indication of the type of information that is contained therein. This includes

(a) information on the weather data (meteorological elements and phenomena, e.g. upper air temperature, CAT areas);

(b) distinguish between meteorological observations, forecasts, advisories, alerts and warnings;

(c) the originating source. AMC-DWD-01/MET.VIS.011 Currency or Age and Validity Time of the Product (a) Each single meteorological information or product displayed shall include a means to

determine the age and valid time(s). (b) Specific product time(s) shall be expressed in Coordinated Universal Time (UTC). (c) Indications of the product age should be readily apparent to the recipient users such that

they do not need to calculate the product age based on its date and time. (d) Specifications for product age and valid time(s) for specific products are provided in the

following paragraphs:

(1) Individual meteorological observations. The date and time that the specific data is observed is the product date and time for individual meteorological observations. The observation date and time shall be indicated on all displays of individual observation reports or sub-elements of those reports (e.g. METAR, weather radar image).

(2) Meteorological forecast products. The date and time the forecast product was issued and the valid time(s) for the specific forecast (e.g. the validity period of a TAF) are two separate but necessary product date(s) and time(s) for meteorological forecast products. Both the issue date and time, and the forecast validity period, shall be indicated on all displays of individual forecast products. If a correction (COR) or an amendment (AMD) of any forecast product is issued, the issue date and time have to be adapted accordingly to the correction or amendment. It is recommended to display the reason of a reissue of a forecast product (COR or AMD) in addition to the issue time.

(3) Composite or mosaic products. These meteorological products are based on a summary or composite presentation of multiple individual observations (or forecasts) covering a defined time interval. The date and time of the last individual report that is incorporated into a composite or mosaic product (cut-off date and time) defines the product date and time for such products.

(4) Sequential or looping product/display. Employing sequential replaying of observed and/or forecast products data sets such as composite weather radar precipitation maps or satellite imagery is a useful way to visualise movement and development of weather. If a sequential data set is replayed, there should be an indication of or means to determine the age of each data set in the sequence during replay.


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If observed and forecast products are combined in a sequential replay, the sequence sorting should be based on the products valid times; and there shall be an indication of or means to determine to differentiate between observation data and forecast data. Looping displays may include meteorological information that has expired or been superseded.

(5) Integrated displays. Displays that integrate dissimilar products or data sets (e.g. METAR, TAF, SIGMET, warnings and alerts) shall include a means for the recipient user to determine the age and valid time of each data set. This is imperative for all integrated displays combining real-time or near-real-time data and observations together with any forecast product.

AMC-DWD-01/MET.VIS.012 Information Necessary for Interpreting a Weather Product (a) Each visualisation of a product shall include a legend or key that defines the meaning of

any symbology, colour-coding and units used in the visualisation. (b) Each visualisation should use consistent visual schemes, including colour, to represent

different meteorological conditions. (c) The legend may optionally include other information that describes the product or data

set characteristics such as the source of the product or specific production algorithm, or confidence levels for forecast products.

(d) For interactive electronic displays that legend or key should be easily accessible to the recipient user, but may optionally be turned off to offer a larger display space for data content. In fixed graphical products a legend shall always be included.

AMC-DWD-01/MET.VIS.013 Product Mapping or Location (a) Each product shall include unambiguous geographic reference information essential for

earth location and/or navigation information. A standard coordinate system, in particular WGS84, should applied whenever possible;

(b) Graphical displays shall clearly indicate the geographic area covered (e.g. area defined by latitude/longitude);

(c) Graphical displays shall, where applicable, indicate the altitude, height or flight level for the product (e.g. 3000 ft AMSL, 150 ft AGL, FL 300, FL 250-630);

(d) If a different geographical projection as included in the meteorological product is used for display, an equal-area projection should be applied.

(e) Any reformatting of the meteorological information should preserve both the geo-location and intensity of the meteorological conditions regardless of projection, scaling, or any other types of processing.

AMC-DWD-01/MET.VIS.014 Product Boundary, Missing or Corrupted Data A positive and clear indication of the availability of the meteorological information in the context of geographic extent, time, and missing or corrupted data shall enable the recipient user to determine areas of uncertainty or missing information. If it is feasible to provide only a selected subset of available meteorological data and information to the recipient user, especially to extract only the necessary information in context of time and/or geographic location, the display for meteorological information shall always indicate the applied extractions.

Any visualisation shall display as applicable:

(a) the geographic extent of the available meteorological information (e.g. an area covered, the borderline of the weather radar composite product);

(b) any missing data (e.g. areas with no contribution of data or gaps due to temporarily sensor failure);

(c) any corrupted data (e.g. due to lost or incomplete transmissions, wrongly coded products).


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AMC-DWD-01/MET.VIS.015 Indication of the Validity of Data Transfer The validity and functionality of the data transfer of meteorological information to be used in the display shall be indicated to the recipient user dependent on the type of transfer:

(a) For fixed telecommunication circuits an indication of data transfer outage is sufficient; however a feature to access technical information on quality and timeliness of the data transfer to the display is recommended;

(b) For uploaded meteorological information via data link the validity and functionality of the data link shall be displayed to the recipient user;

(c) For displays of broadcast meteorological information at least the functionality of the receiving unit and the time of the last successful data reception shall be displayed.

AMC-DWD-01/MET.VIS.020 Product Discard or Suppression Typically an aeronautical meteorological display is designed to provide timely updates of meteorological information and should only provide current and valid information.

(a) Meteorological products should be discarded or suppressed when either a newer version is received or the product expiration time is exceeded;

(b) Whenever new, corrected and/or amended observations, forecasts or other meteorological information of the same type previously issued for the same place and for the same period of validity or part thereof are received they shall replace the now obsolete information;

(c) Time series of data or looping displays may include meteorological information that has expired or has been superseded.

AMC-DWD-01/MET.VIS.030 ICAO Meteorological Reports Textual coded meteorological reports (e.g., METARs and TAFs) shall be displayed or available for display in their original ICAO format as modified by the reporting States. If in addition to the original reports elements of such reports are extracted and displayed separately (e.g. surface visibility trend for the last three METAR reports), the integrity and the accessibility of the original coded text should be maintained. AMC-DWD-01/MET.VIS.035 Graphical Display of ICAO Standard Text Products Whenever a graphical visualisation of a textual coded meteorological product (e.g., METAR, TAF and SIGMET) is applied, a means shall be provided to the recipient user to associate both, the graphical visualisation and the underlying ICAO standard text product. AMC-DWD-01/MET.VIS.040 Formatting of Text Products For the display of textual coded meteorological product it is recommended to use means of digital typography to enhance readability. Text spacing, bold and/or italic fonts, and use of colour may be practical to enhance selected access to meteorological information, especially to single out significant weather information, e.g. operating minima. Any formatting shall not alter or omit the content of a text product. AMC-DWD-01/MET.VIS.050 Graphic Formatting and Display Criteria Graphical meteorological products provide an efficient and effective method for conveying meteorological information to aviation users.

(a) Graphical displays should use existing conventions for plotting or displaying meteorological information as far as possible. Occasionally more than one graphical depiction may be feasible for a single meteorological information (e.g. wind may be displayed as a wind barb, a digit combination of wind direction and wind speed, or colour-coded areas of wind speed). If more than one graphical depiction is used, there shall be no contradictions with regard to content between the various displays.

(b) The use of colour in displays is recommended but is not required. A consistent colour philosophy should be used throughout the display (and across linked applications) which is appropriate in the context of the information being displayed. To the greatest extent practical, colours should be in harmony with other sources of similar information and maintain consistency with all meteorological products used.


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(c) It is recommended to provide means of a context access (e.g. context menu, pop-up menu, mouse-over menu) for the graphical meteorological information as well for the associated time(s) and geographical content (e.g. a context menu for a selected point of a colour coded area of a temperature forecast could write out the temperature, the geographical coordinates and flight level, and the valid time of the forecast).

(d) Integrated displays that combine different meteorological information should use a consistent approach for depicting these various information. There should be a clear differentiation between the different meteorological phenomena or products displayed.

(e) If more than one meteorological element is displayed at a time and overlapping of graphical content is possible it shall be ascertained that all relevant information is accessible to the recipient user. To comply with this requirement, the following measures are recommended:

(1) Combinations of different display techniques like coloured areas, isolines, characters, numerals or symbols;

(2) Use of switchable graphical layers that enable the interactive access to every single element;

(3) Context-sensitive access dependent on geographical position or time.

Personnel and Training (MET.PERS)

AMC-DWD-01/MET.PERS.001 Scope The subpart MET.PERS establishes the training requirements for recipient user personnel to be met to enable the usage of digital meteorological data for operational aviation purposes. AMC-DWD-01/MET.PERS.002 Concurrent Regulations Whenever meteorological information is to be implemented for display in commercial air transport, air traffic services, aerodrome operations, general aviation, search and rescue operations, or any other air navigation service there are usually concurrent regulations in force for personnel training and the subsequent usage of information and products in these respective environments. If such regulations limit or exclude any acceptable means of compliance specified in this AMC, they must be considered prior to this AMC. If such regulations add further requirements, this AMC does not exempt these additional requirements. AMC-DWD-01/MET.PERS.005 General Remarks The display of meteorological products shall enable the recipient users to easily access meteorological information to increase situational awareness and to support decisions. To ensure easy recognition, correct understanding and appropriate application of meteorological information the following essential key elements (MET.PERS.010 - 014) shall be included and addressed in any personnel training. Those responsible for procedures and personnel training should provide adequate training to the recipient users before using an application displaying digital meteorological information. Details and frequency of personnel training should be suitable and adequate to the dedicated aeronautical operation and reflect the operational and safety aspects and limitations for the use of digital weather information concerned. AMC-DWD-01/MET.PERS.010 Basic Training If not covered already by certified training licenses (e.g. CPL/ATPL), the recipient users shall receive a basic training of atmospheric principles and aviation meteorology, including all meteorological elements, phenomena, information and products used in the application in question displaying digital meteorological information to be utilized to conduct aircraft operations, air navigation services and aerodrome operations.


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AMC-DWD-01/MET.PERS.011 Type of Information The recipient users shall be trained to understand the following types and categories of the displayed meteorological information and their respective applications and limitations of use as applicable:

(a) Observations; (b) analyses and composites; (c) nowcasting information; (d) forecasts; (e) advisories; (f) alerts; (g) and warnings.

AMC-DWD-01/MET.PERS.012 Meteorological Products The recipient users training shall address the following issues concerning the meteorological information, time and geo context of the products used:

(a) Source(s) and, if applicable, provider of the product; (b) type(s) and categories of meteorological information; (c) symbology, coding, abbreviations, acronyms, and colours used; (d) interpretation of meteorological elements and phenomena; (e) product valid fixed time or time period, age, product update cycles.

AMC-DWD-01/MET.PERS.013 Display Functions The recipient users training shall address the following issues concerning any display functions used for the access of meteorological information:

(a) Selection or combination of (different) meteorological products; (b) selection of time, particularly toggle between observation and forecast information; (c) selection of geo context; (d) access to legends and context information of displayed data

AMC-DWD-01/MET.PERS.014 Limitations of Use The recipient users training shall address any limitations of the use of the meteorological information on display, addressing:

(a) acceptable use cases (e.g. strategic planning only); (b) knowledge and understanding of the specific system’s capabilities and limitations; (c) reliability of information and sources depicted and any applicable disclaimer by the

service provider; (d) identification and understanding of limitations due to product latency; (e) identification of failures and malfunctions (e.g. incomplete uplinks, missing or corrupt

data); (f) human factors issues (e.g. avoiding fixation; managing workload).

Documentation and Manuals (MET.DOC)

AMC-DWD-01/MET.DOC.001 Scope The subpart MET.DOC establishes recommendations for the documentation and manuals accompanying displays for aeronautical meteorological data. AMC-DWD-01/MET.DOC.002 Concurrent Regulations Whenever meteorological information is to be implemented for display in commercial air transport, air traffic services, aerodrome operations, general aviation, search and rescue operations, or any other air navigation service there are usually concurrent regulations in force for documentation and (operating) manuals and the subsequent usage of information and products in these respective environments.


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If such regulations limit or exclude any acceptable means of compliance specified in this AMC, they must be considered prior to this AMC. If such regulations add further requirements, this AMC does not exempt these additional requirements. AMC-DWD-01/MET.DOC.005 General Remarks The display of meteorological products shall enable the recipient users to easily access meteorological information to increase situational awareness and to support decisions. To ensure easy recognition, correct understanding and appropriate application of meteorological information the following elements (MET.DOC.010 - 014) should be included and addressed in required documentations and operating manuals. The documentations and operating manuals should be suitable and adequate to the dedicated aeronautical operation and reflect the operational and safety aspects and limitations for the use of digital weather information concerned. AMC-DWD-01/MET.DOC.010 Basic Information It is recommended to address the following basic information in accompanying documentations:

(a) description of all meteorological elements, phenomena, information and products used in the application in question displaying digital meteorological information;

(b) description of substantial effects or hazards for aviation in connection with those meteorological phenomena.

AMC-DWD-01/MET.DOC.011 Type of Information The following types and categories of the displayed meteorological information and their respective applications and limitations of use (as applicable) should be included in accompanying documentations:

(a) Observations; (b) analyses and composites; (c) nowcasting information; (d) forecasts; (e) advisories; (f) alerts; (g) and warnings.

AMC-DWD-01/MET.DOC.012 Meteorological Products Accompanying documentations should include details on the following issues concerning the meteorological information, time and geo context of the products used:

(a) Source(s) and, if applicable, provider of the product; (b) type(s) and categories of meteorological information; (c) symbology, coding, abbreviations, acronyms, and colours used; (d) interpretation of meteorological elements and phenomena; (e) product valid fixed time or time period, age, product update cycles.

AMC-DWD-01/MET.DOC.013 Display Functions Accompanying documentations should address the following issues concerning any display functions used for the access of meteorological information:

(a) Selection or combination of (different) meteorological products; (b) selection of time, particularly toggle between observation and forecast information; (c) selection of geo context; (d) access to legends and context information of displayed data.


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AMC-DWD-01/MET.DOC.014 Limitations of Use Accompanying documentations should address any limitations of the use of the meteorological information on display, addressing:

(a) definition of acceptable use cases (e.g. strategic planning only); (b) description of the specific system’s capabilities and limitations; (c) reliability of information and sources depicted and any applicable disclaimer by the

related service providers; (d) description of limitations of the display use due to product latency; (e) description of system failures and malfunctions (e.g. incomplete uplinks, missing or

corrupt data) and accompanying mitigations; (f) information on human factors issues (e.g. avoiding fixation; managing workload).