ECMWF aims to implement IFS blacklist changes in the second week of each month. During the first week, analysts evaluate automated and manual proposals for changes and run model experiments to test the blacklist change. Operational change requests are then submitted in the second week of the month (typically Monday or Tuesday). Occasionally operational IT constraints mean the change is postponed by a few days.
The blacklist changes include preparations for TAC to BUFR migrations. This is clearly indicated in the change document, i.e. denoted by subtype of the observations in the whitelist sections.
Every three months there is a synchronisation with WMO's OSCAR station database. This generally warrants a short blacklist change proposal of its own. The change is integrated into the blacklist code and the relevant change document can be passed on as well.
If you would like to be added to the e-mail distribution of this blacklist information please send an email to ifs_conventional_blacklist-request@lists.ecmwf.int with the word subscribe or unsubscribe as Subject. Please note that this service is restricted to ECMWF Member and Cooperating States.