MANAIR Manual of Standards and Procedures for Aviation Forecasts: chapter 8

Chapter 8 Definitions

The following terms are defined in accordance with their use in this manual. These definitions may not be appropriate for general use.

Abbreviated English
Abbreviated English language using approved Meteorological Service of Canada (MSC) abbreviations as published in Manual of Word Abbreviations (MANAB).
Aerodrome advisory
A forecast, in TAF code, issued for aerodromes which do not fully meet Environment Canada's (EC) weather observing standards.
Aerodrome forecast (TAF)
A forecast, in TAF code, for a designated aerodrome usually issued on a routine basis. It consists of a concise statement of the expected meteorological conditions at the aerodrome for a specified period.
Any area of land, water (including the frozen surface thereof) or other supporting surface used, designed, prepared, equipped or set apart for use, either in whole or in part, for the arrival, departure, movement or servicing of aircraft. This includes any buildings, installations and equipment situated thereon or associated therewith.
Aeronautical Meteorological Forecaster (AMF)
An aeronautical meteorological forecaster is a meteorologist who meets, at a minimum, the definition and top-level competency standards as defined in the Manual on the Implementation of Education and Training Standards in Meteorology and Hydrology, Volume I, Meteorology (WMO-No. 1083), as they pertain to aeronautical meteorology, who is continuously and actively responsible for the content of any aviation weather forecast service. Additional AMF competencies may be required that are in keeping with Canadian regulations.
Air traffic control (ATC)
Service provided by ground-based controllers who direct aircraft on the ground and through controlled airspace. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other support for pilots when able.
Information message to advise pilots of the occurrence or expected occurrence of specified weather phenomena which may affect the safety of aircraft operations, which were not already included in the a Graphic Area Forecasts (GFA), and the development of those phenomena in time and space.
Alittude above ground level (AGL)
The altitude expressed in feet measured above ground level.
Alternate aerodrome (ALTERNATE)
An aerodrome to which an aircraft may proceed when it becomes either impossible or inadvisable to proceed to or land at the aerodrome of intended landing.
Altitude above Sea Level (ASL)
The altitude expressed in feet measured above sea level.
The vertical distance of a level, a point or an object considered as a point, measured from mean sea level.
Area of Responsibility (AOR)
The geographical area over which Canada has the responsibility for providing aviation weather forecast services to civil aviation. This area is composed of all seven Canadian domestic Flight Information Regions (FIRs) as well as the Gander Oceanic FIR/CTA as per international agreement.
Automated Weather Observation System (AWOS)
Automated Weather Observation System - A set of meteorological sensors and associated systems designed to electronically collect and disseminate meteorological data.
Aviation routine weather report (METAR)
An aviation report that describes the actual weather conditions at a specified location and at a specified time as observed from the ground. METAR is the name of the international meteorological code for an aviation routine weather report. METAR observations are normally taken and disseminated on the hour.
Aviation special weather report (SPECI)
A SPECI, the name of the code for an aviation selected special weather report, will be reported when weather changes of significance to aviation are observed.
Aviation weather service
The provision of weather information intended primarily for the safe, regular and efficient conduct of aviation operations.
Canadian Aviation Regulations (CAR)
The rules, enacted under the Aeronautics Act, that govern civil aviation in Canada. Replacing the Air Regulations and the Air Navigation Orders, the CARs and their associated standards came into force on October 10, 1996, after a comprehensive consultation process between Transport Canada and the aviation community. This cooperative and partnership approach to rule-making continues within the Canadian Aviation Regulation Advisory Council (CARAC), which discusses proposed amendments to the CARs and their associated standards.
Canadian Meteorological Aviation Centre (CMAC)
A meteorological centre dedicated to production of aviation weather forecasts and the monitoring of meteorological conditions which may affect flight operations in Canada. As such a CMAC fulfills the role of a meteorological watch office (MWO).
Canadian Meteorological Centre (CMC)
The component of the MSC responsible for the assimilation of weather data for objective and subjective analyses and forecasts and for generating numerical weather prediction products as guidance to support forecast production centres.
The lesser of the height above ground or water of the base of the lowest layer of cloud where the summation amount exceeds half the sky (more than four eights (4/8)) or the vertical visibility in a surface-based layer which completely obscures the sky.
Control area (CTA)
A controlled airspace extending upwards vertically from a specified height above the surface of the earth.
Department of National Defence (DND)
Federal government department with the authority and responsibility to provide and arrange the provision of meteorological services to support the safe, efficient conduct of military aviation operations and training.
Domestic aviation
All aviation operations taking place solely within Canada. It specifically excludes trans-border (Canada-United States) and all other international air transport operations.
Environment Canada (EC)
Canadian federal government department responsible for providing meteorological information to Canadians to ensure their safety and promote informed decision making related to the environment.
Flight Information Region (FIR)
An airspace of defined dimensions extending upwards from the surface of the earth within which Flight Information Service (FIS) and alerting service are provided.
Flight Level (FL)
A standard nominal altitude of an aircraft, in hundreds of feet. This altitude is calculated from the international standard pressure datum of 1013.25 hPa (29.92 inHg), the average sea-level pressure, and therefore is not necessarily the same as the aircraft's true altitude either above mean sea level or above ground level.
A statement of expected meteorological conditions for a specified time or period, and for a specified area or portion of airspace.
Graphic Area Forecast (GFA)
A forecast in chart form describing the most probable meteorological conditions expected to occur between the surface and 24,000 feet over a given area at a specified time.
The vertical distance of a level, a point or an object considered as a point, measured from a specified datum, e.g. above ground.
International Civil Aviation Organization (ICAO)
A specialized agency of the United Nations, the objective of which is to develop the principles and techniques of international air navigation and to foster planning and development of international civil air transport.
Manual of word abbreviations authorized for use in transmissions over Environment Canada’s Telecommunication Networks.
Manual of surface weather observations which prescribes the standard procedures of the Meteorological Service of Canada for observing, recording and reporting weather conditions.
Meteorological Service of Canada (MSC)
The component of Environment Canada (EC) that leads, serves as the national focus, provides science, policy and service support to EC. MSC also provides ice services, including research, systematic observations and forecasts directly to clients. MSC coordinates nationally the standards for the delivery of the aviation weather program as required by Transport Canada and NAV CANADA. Furthermore, MSC prepares and delivers aviation and other forecast products required by the Department of National Defence (DND).
Meteorological Watch Office (MWO)
An office that maintains a continuous watch over meteorological conditions affecting flight operations within its specified area of responsibility. An MWO is responsible for the provision of SIGMET and AIRMET information as well as pertinent information on volcanic activity and radioactive release to the Air Navigation Services provider.
A private sector non-share capital corporation, financed through publicly-traded debt, which owns and operates Canada’s civil air navigation system. NAV CANADA has the responsibility for the provision of aviation weather services in Canadian airspace and any airspace in respect of which Canada has the responsibility for the provision of air traffic control services. NAV CANADA also specifies the location and frequency of aviation weather observations and forecasts, and is responsible for the dissemination of this information for aviation purposes.
A portion or a segment of the period of validity of a forecast.
Period of coverage
The span of time which a TAF program covers daily.
Period of validity
The span of time which a forecast encompasses. Also called "valid period," it is part of the aerodrome forecast. It must, however, be kept in mind that a forecast is only valid until another forecast is (regular, amended or corrected) is issued for the same area of responsibility or the same aerodrome.
Pilot report (PIREP)
A report by a pilot pertaining to weather conditions encountered in flight.
Plain English
As used in this manual, the expression "Plain English" is intended to mean non-abbreviated English language in a telegraphic type format intended to convey meteorological information to the aviation community as effectively and as efficiently as possible.
Prognostic chart
A forecast of one or several specified meteorological element for a specified time or period and a specified surface or portion of airspace, depicted graphically on a chart.
RCAP (Restricted Canada Air Pilot)
Approach plates for non-standard approaches or company specific approaches.
RNAV (Area navigation)
A method of navigation which permits aircraft operation on any desired flight path within the coverage of ground- or space-based NAVAIDs or within the limits of the capability of self-contained aids, or a combination of these.
An information message issued by a meteorological watch office (MWO) to advise pilots of the occurrence or expected occurrence of specified weather phenomena, which may affect the safety of aircraft operations, and the development of those phenomena in time and space.
Transport Canada (TC)
The federal authority responsible for the regulation of civil aviation.
Valid period
Alternate term for “Period of validity.”
Weather station
An establishment primarily responsible for the observing and reporting of weather conditions. The station may be operated by a human observer, a fully automated system or a combination of both. Complete or partial sets of meteorological parameters may be observed.
World Area Forecast System (WAFS)
A worldwide satellite broadcast system by which World Area Forecast Centres (WAFC) provide meteorological information for aviation purposes. These broadcasts are supervised by International Civil Aviation Organization (ICAO) in order to fulfill requirements of the ICAO Annex 3 covering meteorological information which is necessary for flights.
World Meteorological Organization (WMO)
A specialized agency of the United Nations (UN). It is the UN system's authoritative voice on the state and behavior of the Earth's atmosphere, its interaction with the oceans, the climate it produces and the resulting distribution of water resource.
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