earth science

IWXXM

IWXXM is a earth science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand IWXXM rather than just read about it. In short: ICAO Meteorological Information Exchange Model (IWXXM) is a format for reporting weather information in XML/GML. IWXXM includes XML/GML-based representations for products standardized in International Civil Aviation Organization (ICAO) Annex III, such as METAR/SPECI, TAF, SIGMET, AIRMET, Tropical Cyclone Advisory (TCA), Volcanic Ash Advisory (VAA), Space Weather Advisory and World Area Forecast System (WAFS) Signifi…

Key takeaways

IWXXM belongs to earth science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect IWXXM to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of IWXXM from memory before moving on to harder problems.

Reference excerpt

ICAO Meteorological Information Exchange Model (IWXXM) is a format for reporting weather information in XML/GML. IWXXM includes XML/GML-based representations for products standardized in International Civil Aviation Organization (ICAO) Annex III, such as METAR/SPECI, TAF, SIGMET, AIRMET, Tropical Cyclone Advisory (TCA), Volcanic Ash Advisory (VAA), Space Weather Advisory and World Area Forecast System (WAFS) Significant Weather (SIGWX) Forecast. IWXXM products are used for operational exchanges of meteorological information for use in aviation. ICAO Annex 3 defines what IWXXM capability is required at different time frames. These capabilities can also be considered in context of the ICAO SWIM-concept (Doc 10039, Manual on System Wide Information Management (SWIM) Concept). Unlike the traditional forms of the ICAO Annex III products, IWXXM is not intended to be directly used by aircraft pilots. IWXXM is designed to be consumed by software acting on behalf of pilots, such as display software.

History IWXXM Version 1 was introduced in October 2013, representing METAR, SPECI, TAF and SIGMET formats as specified in International Civil Aviation Organization (ICAO) Annex III, Amendment 76. IWXXM became an optional format for the bilateral exchange of weather reports in November 2013 when the amendment became applicable. The seventeenth WMO Congress approved IWXXM 1.1, a WMO standard data representation to be included in the new Volume I.3 of WMO-No. 306, Manual on Codes. IWXXM Version 2 was issued in August 2016 with the introduction of new products including AIRMET, Tropical Cyclone Advisory and Volcanic Ash Advisory, loads of improvements and bug fixes. Supported by the sixteenth session of the WMO Commission for Basic System in 2016, a slightly revised version IWXXM 2.1 has been approved by the sixty-ninth WMO Executive Council in May 2017. A patch (IWXXM Version 2.1.1) had been released and approved in Nov 2017 to fix minor issues on validation and examples. IWXXM Version 3 was first made available as version 3.0RC1 in July 2018. Major changes include restructuring and simplifying with the removal of Observations and Measurements model (O&M), addition of the new Space Weather Advisory and other changes with regard to Amendment 78 to ICAO Annex 3, and numerous fixes and enhancements. IWXXM 3.0RC2 was released in October 2018 for further comments. Another release candidate IWXXM 3.0RC3 was released in April 2019. Approval was received in October 2019 and IWXXM 3.0RC4 was released before publishing of the finalized version on 7 November 2019. IWXXM Version 2021-2 was published in Nov 2021 meeting new requirements in Amendments 79 and 80 to ICAO Annex 3, including the introduction of the new WAFS SIGWX Forecast to be provided by World Area Forecast Centers (WAFCs) by 2023. A bug fix version (IWXXM Version 2023-1) was published on 15 June 2023 to fix a few bugs involved in the schematron rules as well as introducing the missing icing phenomenon required in WAFS SIGWX Forecast. A new version of IWXXM is being developed in response to the proposed changes in the upcoming Amendment 81 to ICAO Annex 3.

Regulation IWXXM is regulated by WMO in association with ICAO. IWXXM is defined at the technical regulation level in WMO No.306 Volume I.3 to meet the regulatory requirements described in ICAO Annex III. Another document ICAO Doc 10003 is also available to provide a high level description of the model.

Development The WMO Commission for Observation, Infrastructures and Information Systems (INFCOM) Task Team on Aviation Data or TT-AvData (previously Commission for Basic System (CBS) Task Team on Aviation XML or TT-AvXML) and ICAO Meteorological Panel (METP) Working Group on Meteorological Information Exchange (WG-MIE) are involved in the development of IWXXM. The e-mail group was created to collect feedback from users. A GitHub repository has been created to engage community participation.

Relationship with WXXM WXXM is governed by FAA and EUROCONTROL for international products outside of those represented by ICAO or WMO. WXXM 1.0 was released in 2007. There were no new releases since the publication of WXXM 3.0.0 in 2019.

See also METAR/SPECI TAF SIGMET AIRMET Tropical Cyclone Advisory Volcanic Ash Advisory Space Weather Advisory WAFS Significant Weather Forecast

References

External links WMO IWXXM Schema Repository WMO Web-Accessible Codes Registry

Worked examples

Example 1 — a first encounter with IWXXM

Start with the simplest possible case. Write down what IWXXM claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In earth science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to IWXXM before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about IWXXM ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of IWXXM

In research: IWXXM appears in earth science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses IWXXM in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: IWXXM is common in secondary-school and first-year university syllabi. It links to neighbouring topics Aviation meteorology, Meteorological data and networks, Weather forecasting, so understanding it makes those chapters shorter.
In everyday life: Look for IWXXM outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study IWXXM in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what IWXXM means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain IWXXM out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is IWXXM in simple terms?

Why does IWXXM matter?

Because it connects several earth science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study IWXXM?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on IWXXM.