The originating OAC identifies each NAT Track Message, within the Remarks section appended to the end of the NAT Track message, by means of a 3-digit Track Message Identification (TMI) number equivalent to the Julian calendar date on which that OTS is effective. For example, the OTS effective on February 1st will be identified by TMI 032. (The Julian calendar date is a simple progression of numbered days without reference to months, with numbering starting from the first day of the year.).
In case the North Atlantic Tracks are modified, a letter is appended to the TMI number:
If any subsequent NAT Track amendments affecting the entry/exit points, route of flight (co-ordinates) or flight level allocation are made, the whole NAT Track Message will be re-issued. The reason for this amendment will be shown in the Notes and a successive alphabetic character, i.e. ‘A’, then ‘B’, etc., will be added to the end of the TMI number (e.g. TMI 032A).
I would like to know how such change is notified to the interested parties; is some ATCs issuing a NOTAM to declare that some changes have been done to the TM? If yes, where can I visualize such NOTAM?
One possible way to overcome my problem would consist in constantly checking if the TMI number has changed but this is not a very efficient way to proceed. I would rather expect some NOTAM which notifies the TMI number change.
Can you tell me if what I ask is plausible? If yes how can I proced?