--- title: "MET.TR.235 Aerodrome warnings and wind shear warnings and alerts — SPECIFIC REQUIREMENTS FOR PROVIDERS OF METEOROLOGICAL SERVICES, ATM/ANS · Avioverse" description: "Wind shear warnings shall be issued in accordance with the template in Appendix 4." url: "https://avioverse.aero/regulations/easa/atm-ans/part-met/subpart-b/met-tr-235" --- # MET.TR.235 Aerodrome warnings and wind shear warnings and alerts SPECIFIC REQUIREMENTS FOR PROVIDERS OF METEOROLOGICAL SERVICES · Regulation (EU) 2017/373 · EAR revision 12 Mar 2025 Official sources: [EASA Easy Access Rules (opens in a new tab)](https://www.easa.europa.eu/en/document-library/easy-access-rules/easy-access-rules-air-traffic-managementair-navigation-services-provision-services) · [EUR-Lex 2017/373 (opens in a new tab)](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32017R0373) IR Implementing rule ## MET.TR.235 Aerodrome warnings and wind shear warnings and alerts (a) Wind shear warnings shall be issued in accordance with the template in Appendix 4. (b) The sequence number referred to in the template in Appendix 4 shall correspond to the number of wind shear warnings issued for the aerodrome since 00.01 UTC on the day concerned. (c) Wind shear alerts shall give concise, up-to-date information related to the observed existence of wind shear involving a headwind/tailwind change of 15 kt or more which could adversely affect aircraft on the final approach path or initial take-off path and aircraft on the runway during the landing roll or take-off run. (d) Wind shear alert shall, if practicable, relate to specific sections of the runway and distances along the approach path or take-off path as agreed between the aerodrome meteorological office, the appropriate ATS units and the operators concerned. IR · MET.TR.235 — Regulation (EU) 2017/373 · Regulation (EU) 2021/1338 · ATM/ANS Easy Access Rules · EAR revision 12 Mar 2025 AMC Acceptable means of compliance ## AMC1 MET.TR.235 Aerodrome warnings and wind shear warnings and alerts AERODROME WARNINGS — TEMPLATE FOR AERODROME WARNINGS Aerodrome warnings should be issued in accordance with the template below or in another format where required by operators or aerodrome meteorological offices. | Template for aerodrome warnings Key: M = inclusion mandatory; C = inclusion conditional, included whenever applicable. Note 1: The ranges and resolutions for the numerical elements included in aerodrome warnings are provided in GM1 MET.TR.235. Note 2: The row numbers in the ‘Ref.’ column are included only for clarity and ease of reference, and are not part of the aerodrome warning. | | | | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Ref. | Element | Detailed content | Templates | | 1 | Location indicator of the aerodrome (M) | Location indicator of the aerodrome | nnnn | | 2 | Identification of the type of message (M) | Type of message and sequence number | AD WRNG \[n]n | | 3 | Validity period (M) | Day and time of validity period in UTC | VALID nnnnnn/nnnnnn | | 4 | IF THE AERODROME WARNING IS TO BE CANCELLED, SEE DETAILS AT THE END OF THE TEMPLATE. | | | | 5 | Phenomenon (M) | Description of the phenomenon causing the issuance of the aerodrome warning | TC nnnnnnnnnn or \[HVY] TS or GR or \[HVY] SN \[nnCM] or \[HVY] FZRA or \[HVY] FZDZ or RIME or \[HVY] SS or \[HVY] DS or SA or DU or SFC WSPD nn\[n]KT MAX nn\[n] or SFC WIND nnn/nn\[n]KT MAX nn\[n] or SQ or FROST or TSUNAMI or VA\[DEPO] or TOX CHEM or Free text up to 32 characters | | 6 | Observed or forecast phenomenon (M) | Indication whether the information is observed and expected to continue, or forecast | OBS \[AT nnnnZ] or FCST | | 7 | Changes in intensity (C) | Expected changes in intensity | INTSF or WKN or NC | | OR | | | | | 8 | Cancellation of the aerodrome warning | Cancellation of the aerodrome warning referring to its identification | CNL AD WRNG \[n]n nnnnnn/nnnnnn | (b) When the above template is used, the sequence number referred to in the template should correspond to the number of aerodrome warnings issued for the aerodrome since 00.01 UTC on the day concerned. AMC · AMC1 MET.TR.235 — Regulation (EU) 2017/373 · ED Decision 2022/004/R · ATM/ANS Easy Access Rules · EAR revision 12 Mar 2025 GM Guidance material ## GM1 MET.TR.235 Aerodrome warnings and wind shear warnings and alerts RANGES AND RESOLUTIONS — AERODROME WARNINGS (a) The ranges and resolutions for the numerical elements included in aerodrome warnings are shown below: | Ranges and resolutions for the numerical elements included in volcanic ash and tropical cyclone advisories, SIGMET, AIRMET, aerodrome and wind shear warnings Note: The row numbers in the ‘Ref.’ column are included only for clarity and ease of reference, and are not part of the template. | | | | | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------- | ------------- | ---------- | | Ref. | Elements | Range | Resolution | | 1 | Summit elevation: FT | 000–27 000 | 1 | | | M | 000–8 100 | 1 | | 2 | Advisory number: for VA (index)\* | 000–2 000 | 1 | | | for TC (index)\* | 00–99 | 1 | | 3 | Maximum surface wind: KT | 00–199 | 1 | | 4 | Central pressure: hPa | 850–1 050 | 1 | | 5 | Surface wind speed: KT | 30–99 | 1 | | 6 | Surface visibility: M | 0000–0750 | 50 | | | M | 0800–5 000 | 100 | | 7 | Cloud: height of base: FT | 000–1 000 | 100 | | 8 | Cloud: height of top: FT | 000–9 900 | 100 | | | FT | 10 000–60 000 | 1 000 | | 9 | Latitudes: ° (degrees) | 00–90 | 1 | | | (minutes) | 00–60 | 1 | | 10 | Longitudes: ° (degrees) | 000–180 | 1 | | | (minutes) | 00–60 | 1 | | 11 | Flight levels: | 000–650 | 10 | | 12 | Movement: KT | 0–150 | 5 | | | KMH | 0–300 | 10 | | \* Non-dimensional | | | | (b) The explanations for the abbreviations can be found in ICAO Doc 8400 'Procedures for Air Navigation Services — ICAO Abbreviations and Codes (PANS-ABC)'. GM · GM1 MET.TR.235 — Regulation (EU) 2017/373 · ED Decision 2022/004/R · ATM/ANS Easy Access Rules · EAR revision 12 Mar 2025 GM Guidance material ## GM2 MET.TR.235 Aerodrome warnings and wind shear warnings and alerts AERODROME WARNINGS — EXAMPLES OF ELEMENTS Non-exhaustive examples of the different elements used in the formulation of aerodrome warnings are provided below. | Aerodrome warning — examples of elements Note 1: Consult the ‘aerodrome warning’ template in AMC1 MET.TR.235 to identify the mandatory (M), the conditional (C) or the optional (O) elements. Note 2: The ranges and resolutions for the numerical elements included in aerodrome warnings are provided in GM1 MET.TR.235. Note 3: The row numbers in the ‘Ref.’ column are included only for clarity and ease of reference, and are not part of the aerodrome warning. They do not correlate with the ‘Ref.’ column in AMC1 MET.TR.235. Refer to the ‘Element’ column when cross-referencing. | | | | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------ | ----------------------------------------------------------------------- | | Ref. | Element | Examples | | 1 | Location indicator of the aerodrome | YUCC | | 2 | Identification of the type of message | AD WRNG 2 | | 3 | Validity period | VALID 211230/211530 | | 4 | IF THE AERODROME WARNING IS TO BE CANCELLED, SEE DETAILS AT THE END OF THE TEMPLATE. | | | 5 | Phenomenon | TC ANDREW HVY SN 25CM SFC WSPD 40KT MAX 60 SFC WIND 230/40KT VA TSUNAMI | | 6 | Observed or forecast phenomenon | OBS AT 1200Z OBS | | 7 | Changes in intensity | WKN | | | OR | | | 8 | Cancellation of the aerodrome warning | CNL AD WRNG 2 211230/211530 | GM · GM2 MET.TR.235 — Regulation (EU) 2017/373 · ED Decision 2022/004/R · ATM/ANS Easy Access Rules · EAR revision 12 Mar 2025 GM Guidance material ## GM3 MET.TR.235 Aerodrome warnings and wind shear warnings and alerts Phenomenon (M) — TOX CHEM When issuing an aerodrome warning due to information related to toxic chemical affecting an aerodrome and or volcanic ash deposition, the warning should be filed by means of the use of free text up to 32 characters, e.g. TOX CHEM FCST XXXX AIRPORT NEARBY WKN. (XXXX = ICAO Location Indicator) GM · GM3 MET.TR.235 — Regulation (EU) 2017/373 · ED Decision 2022/004/R · ATM/ANS Easy Access Rules · EAR revision 12 Mar 2025 AMC Acceptable means of compliance ## AMC1 MET.TR.235(a) Aerodrome warnings and wind shear warnings and alerts AERODROME WARNINGS — FORMAT (a) The additional text should be prepared in abbreviated plain language using approved ICAO abbreviations and numerical values. If no ICAO-approved abbreviations are available, English plain language text should be used. (b) When quantitative criteria are necessary for the issuance of aerodrome warnings, the criteria used should be as agreed between the aerodrome meteorological office and the users concerned. AMC · AMC1 MET.TR.235(a) — Regulation (EU) 2017/373 · ED Decision 2020/008/R · ATM/ANS Easy Access Rules · EAR revision 12 Mar 2025 AMC Acceptable means of compliance ## AMC1 MET.TR.235(c) Aerodrome warnings and wind shear warnings and alerts WIND SHEAR WARNINGS - FORMAT (a) The use of text in addition to the abbreviations listed in the template in Appendix 4 should be kept to a minimum. The additional text should be prepared in abbreviated plain language using ICAO-approved abbreviations and numerical values. (b) When an aircraft report is used to prepare a wind shear warning or to confirm a warning previously issued, the corresponding aircraft report, including the aircraft type, should be disseminated unchanged in accordance with the local arrangements to those concerned. AMC · AMC1 MET.TR.235(c) — Regulation (EU) 2017/373 · ED Decision 2022/004/R · ATM/ANS Easy Access Rules · EAR revision 12 Mar 2025 GM Guidance material ## GM1 MET.TR.235(a) Aerodrome warnings and wind shear warnings and alerts WIND SHEAR TYPES Following reported encounters by both arriving and departing aircraft, two different wind shear warnings may exist: one for arriving aircraft and one for departing aircraft. GM · GM1 MET.TR.235(a) — Regulation (EU) 2017/373 · ED Decision 2020/008/R · ATM/ANS Easy Access Rules · EAR revision 12 Mar 2025 GM Guidance material ## GM2 MET.TR.235(a) Aerodrome warnings and wind shear warnings and alerts REPORTING THE INTENSITY OF WIND SHEAR Specifications for reporting the intensity of wind shear are still under development. It is recognised, however, that pilots, when reporting wind shear, may use the qualifying terms ‘moderate’, ‘strong’ or ‘severe’, based to a large extent on their subjective assessment of the intensity of the wind shear encountered. GM · GM2 MET.TR.235(a) — Regulation (EU) 2017/373 · ED Decision 2020/008/R · ATM/ANS Easy Access Rules · EAR revision 12 Mar 2025 GM Guidance material ## GM1 MET.TR.235(c) Aerodrome warnings and wind shear warnings and alerts DETECTION OF WIND SHEAR Wind shear conditions are normally associated with the following phenomena: (a) thunderstorms, microbursts, funnel cloud, tornado or waterspout, and gust fronts; (b) frontal surfaces; (c) strong surface winds coupled with local topography; (d) sea breeze fronts; (e) mountain waves, including low-level rotors in the terminal area; (f) low-level temperature inversions. GM · GM1 MET.TR.235(c) — Regulation (EU) 2017/373 · ED Decision 2020/008/R · ATM/ANS Easy Access Rules · EAR revision 12 Mar 2025 GM Guidance material ## GM1 MET.TR.235(d) Aerodrome warnings and wind shear warnings and alerts DISSEMINATION OF WIND SHEAR ALERTS The wind shear alerts are disseminated from automated, ground-based, wind shear remote-sensing or detection equipment in accordance with local arrangements to those concerned. GM · GM1 MET.TR.235(d) — Regulation (EU) 2017/373 · ED Decision 2017/001/R · ATM/ANS Easy Access Rules · EAR revision 12 Mar 2025 [All rules in SUBPART B — TECHNICAL REQUIREMENTS FOR PROVIDERS OF METEOROLOGICAL SERVICES (MET.TR)](https://avioverse.aero/regulations/easa/atm-ans/part-met/subpart-b) Consolidated from the EASA Easy Access Rules (revision 12 Mar 2025, extracted 2 Nov 2026) for convenience. Not the official publication — verify against the Official Journal of the European Union and the EASA publications before operational use.