VA Advisory (ICAO)

Required roles: AIS PIB API — Roles
Base endpoint: https://ais-pib-api.ibosoft.net.tr:2087/opmet-decoder-va-icao
Reference documents: ICAO Doc 10157 PANS-MET, Ed. 1 (27/11/25) · ICAO Doc 8400 PANS-ABC, Ed. 9, Amend. 33 (8/11/18)
Attribution: show ibonav.aero or "Decoded by Ibosoft" wherever decoded output is displayed
Data sources: none — decodes the message supplied in the request.
Last updated: 17 OCT 2026

About the reference documents: Related Documents and Resources

Decodes a volcanic ash advisory into readable fields, following the PANS-MET template. Optionally returns the volcano position and the ash-cloud areas in decimal degrees (parsed), ready for a map.

The format is that of PANS-MET Table A7-2. To get advisories to decode, see VA Advisory. A VONA is a different message: see VONA (ICAO).

Endpoints

POST /opmet-decoder-va-icao/decode?parsed=false
Content-Type: application/json

{ "raw": "<VA advisory text>" }

Parameters

Parameter	In	Default	Description
`raw`	body	—	Advisory text, at least 10 characters. A WMO bulletin heading is accepted and removed.
`parsed`	query	`false`	`true`: add the `parsed` object

How the template is processed

The advisory is line based: each element starts with its heading and a colon (DTG:, VAAC:, OBS VA CLD: …); the value runs to the next heading.
Field names and wording come from PANS-MET Table A7-2: output keys are the template element names; times, coordinates (N5403 E15927 → N54°03' E159°27'), levels and movements are written out. Abbreviations are expanded as defined in PANS-MET and PANS-ABC (Doc 8400).
M (mandatory) elements are always present (null when missing); C (conditional) elements (e.g. status TEST/EXER) only when present.
Ash clouds: the observed/estimated cloud and the +6, +12 and +18 hour forecasts are separate elements; NO VA EXP reads "No volcanic ash expected".
Values that do not follow the template are listed under Undecodable elements (neighbouring groups form one entry).

For the full list of elements, see PANS-MET Table A7-2.

Response

Example — PANS-MET Example A7-2 (shortened):

VA ADVISORY
DTG: 20240923/0130Z
VAAC: TOKYO
VOLCANO: KARYMSKY 300130
PSN: N5403 E15927
…
FCST VA CLD +18 HR: 23/1900Z NO VA EXP
NXT ADVISORY: 20240923/0730Z

{
  "Identification of the type of message": "Volcanic ash advisory",
  "Time of origin": "2024-09-23 01:30 UTC",
  "Name of VAAC": "TOKYO",
  "Name of volcano": "KARYMSKY 300130",
  "Location of volcano": "N54°03' E159°27'",
  "State or region": "RUSSIAN FEDERATION",
  "Advisory number": "2024/4",
  "Forecast ash cloud +18 HR": "Day 23 19:00 UTC No volcanic ash expected",
  "Next advisory": "2024-09-23 07:30 UTC",
  "…": "…",
  "positions": [{"start": 0, "end": 11}, "…"],
  "corrected_raw": "VA ADVISORY\nDTG: 20240923/0130Z\n…",
  "raw": "…",
  "parsed": {
    "utc_day": 23, "utc_time": "0130",
    "vaac": "TOKYO", "advisory_number": "2024/4",
    "position": {"lat": 54.05, "lon": 159.45},
    "extent": [
      {"phase": "Observed", "points": [{"lat": 54.0, "lon": 159.5}, "…"]},
      {"phase": "Forecast +6h", "points": ["…"]},
      {"phase": "Forecast +12h", "points": ["…"]}
    ]
  }
}

Key	Description
element keys	Decoded elements, in template order
`Undecodable elements`	Values that do not follow the template (only when there are any)
`corrected_raw`	The message after normalization; `positions` refer to this text
`positions`	Character spans `{start, end}` in `corrected_raw`, one per decoded value in output order
`parsed`	With `parsed=true`: time of origin (`utc_day`, `utc_time`), `vaac`, `advisory_number`, volcano `position` (`lat`/`lon`, signed decimal degrees) and `extent` — the ash-cloud areas per phase (`Observed`, `Forecast +6h`, `+12h`, `+18h`) as point lists

Errors

Code	Meaning
`400`	The message could not be parsed at all; `detail` explains why
`422`	`raw` is missing or shorter than 10 characters

VA Advisory (ICAO)#

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How the template is processed#

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