The SNOWTAM is a special series NOTAM notifying the presence or removal of hazardous conditions due to snow, ice, slush or standing water associated with snow, slush and ice on the movement area, by means of a specific format.
When information concerning snow, slush, ice and standing water is reported by means of a SNOWTAM, the message shall contain the information in the order of the SNOWTAM Format as provided in ICAO Annex 15.
The need for SNOWTAM encoding guidelines was identified by EUROCONTROL during the execution of the Digital SNOWTAM Trial held during the period of December 2009 to May 2010.
The automatic analysis of the incoming SNOWTAM messages showed that many originators and NOTAM offices have difficulties in adhering to the ICAO SNOWTAM syntax, especially for States that only occasionally issue such messages.
In order to support the States improve their SNOWTAM encoding, EUROCONTROL has with the support of the AI Operations Subgroup members and approval by the AIM/SWIM Team developed a set of SNOWTAM harmonisation guidelines.
The purpose of this document is to provide guidance to NOTAM operators and airport managers in correctly filling the various fields of the SNOWTAM message. The document includes examples of correct SNOWTAM format in grey shading. Also, to enable users to avoid syntactical errors, instructions are included in italic text which includes some ´not to do´ examples.
The guidelines do not contradict at any point the ICAO SARPS contained in Annex 15. Instead, these guidelines repeat and expand the ICAO SARPS with examples and suggestions based on real world "contamination" situations.
The updated version of the guidelines reflects the changes to the SNOWTAM format as provided by Amendment 37 to ICAO Annex 15 (applicable 14 November 2013), including the introduction of repeated item B when reporting on more than one runway and the change in reporting format in item H (estimated surface friction).
The document deals only with the syntactical correctness of the SNOWTAM messages. It does not provide operational guidelines, such as those provided by ICAO Annex 15, Appendix 2 or by other ICAO or Regional documents and circulars.
Some contents are as follows:
Minimal SNOWTAM information, Several fields on a single line and line feed, Runway closed, SNOWTAM numbering, SNOWTAM validity, Change in conditions - issue a new SNOWTAM, Use of “COR” in the Abbreviated heading, complete explanation of SNOWTAM fields, aerodrome location indicator, runway designator, cleared runway length etc.