Hi I am not a specialist, so sorry if it will not fit your question. I found a use case of INSPIRE that it might be related. Please, see here: http://inspire.ec.europa.eu/documents/Data_Specifications/INSPIRE_DataSpecification_AF_v3.0.pdf (Page 106)
Frederic, just as a remark: I'm sure you have looked for metadata regarding weather forecasts and hindcasts, which may be used as a basis for early warnings.