Skip to content

RA 2019_01

Jump to bottom
BL Choy edited this page Jul 21, 2021 · 1 revision

--- Draft (First created on 20 May 2019. Updated on 10 Dec 2020). To be reviewed by TT-AvXML members ---

Amendment 79 to ICAO Annex 3 approved by the Air Navigation Commission

The proposed amendment (Amendment 79) to Annex 3 is envisaged for applicability on 5 Nov 2020, except for the provisions related to the dissemination of significant weather (SIGWX) forecasts in IWXXM GML form which are envisaged on 4 Nov 2021.

Comparison

Comparison is made against IWXXM version 3.0.0.

Details of the proposed changes

Proposal 1: Re-suspended volcanic ash

Table A2-1. Template for advisory message for volcanic ash

Analysis

  • Name of volcano: No change is required.
  • State or region: To accommodate the introduction of an "UNKNOWN" state or region a minor change to the schemas to allow the use of xsi:nil is required. An an update to TAC-to-XML Guidance on using the appropriate nilReason is also required.
  • Summit elevation: A minor change to the schema is required to introduce the concept of "SFC" which does not necessarily at 0 meters/feet on the referenced vertical datum. "UNKNOWN" can already be represented with the existing schema.
  • Information source: No change is required.
  • Eruption details: No change is required.
  • Remarks: No change is required.

Proposal 5: World Area Forecast System (WAFS) information

As of 4 Nov 2021, ..., SIGWX forecasts should be disseminated in IWXXM GML form.

Analysis

A minor change is required to accommodate new features of IWXXM for SIGWX forecasts.

Proposal 6: Tropical cyclone advisories and SIGMET for tropical cyclone

Table A2-2. Template for advisory message for tropical cyclones

Analysis

  • Identification of the type of message: No changes can be identified.
  • Observed CB cloud: No change to the schema is required. An update to TAC-to-XML Guidance on using the appropriate nilReason is required.
  • Changes in intensity: A minor change is required to introduce the new element.

Proposal 7: Space weather advisory information provisions

Table A2-3. Template for advisory message for space weather information

Analysis

  • Space weather effect and intensity: No change is required.
  • Observed or expected space weather phenomena: No change is required.
  • Forecast of the phenomena: No change is required.
  • Next advisory: No change is required.

Proposal 8: Indication of missing and/or incorrect parameters in METAR

Table A3-2. Template for METAR and SPECI (Part I) Table A3-2. Template for METAR and SPECI (Part II) Table A3-2. Template for METAR and SPECI (Part III)

Analysis

  • Surface wind, visibility, runway visual range, cloud, air and dew point temperature, pressure values: No change is required.
  • Sea-surface temperature and state of the sea or significant wave height: No change is required.
  • Sate of the runway: A minor change is required to remove the element (The removal has been deferred in Amendment 80 to Nov 2021).
  • Trend forecast: No change is required.

Proposal 11: Release of radioactive material in the atmosphere (There were some other fixes to the SIGMET/AIRMET template too)

Table A6-1A. Template for SIGMET and AIRMET messages (Part I) Table A6-1A. Template for SIGMET and AIRMET messages (Part II) Table A6-1A. Template for SIGMET and AIRMET messages (Part III) Table A6-1A. Template for SIGMET and AIRMET messages (Part IV) Table A6-1A. Template for SIGMET and AIRMET messages (Part V) Table A6-1A. Template for SIGMET and AIRMET messages (Part VI)

Analysis

  • Status indicator: No change can be identified.
  • Observed or forecast phenomenon, Level, Movement or expected movement, Change in intensity, Forecast time, TC forecast position, Forecast position, Repetition of phenomenon: A minor change is required which include:
    • change the multiplicity of iwxxm:eruptingVolcano and iwxxm:tropicalCyclone from [0..2] to [0..1] as only one volcano or tropical cyclone can be described in a SIGMET message.
    • deprecate the use of @volcanoId and @tropicalCycloneId as ash cloud/volcano and CB/tropical cyclone relationship can no longer be ambiguous.
    • change the multiplicity of iwxxm:analysis and iwxxm:forecastPositionAnalysis from [0..2] to [0..*]to allow for more than one OBS/FCST + FCST description connected by "AND" in Volcanic Ash SIGMET and Tropical Cyclone SIGMET.
  • Cancellation of SIGMET/AIRMET: No change is required.

Conclusion

  • METAR/SPECI: A minor No change is required (until Nov 2021).
  • TAF: No change is required.
  • SIGMET: A minor change is required.
  • AIRMET: A minor change is required.
  • Tropical Cyclone Advisory: A minor change is required.
  • Volcanic Ash Advisory: A minor change is required.
  • Space Weather Advisory: No change is required.
  • SIGWX forecasts: A minor change is required to accommodate the new features.

... go to TT-AvData Homepage on WMO Community website

Clone this wiki locally